TY - JOUR
A1 - Xu, Yaolin
A1 - Dong, Kang
A1 - Jie, Yulin
A1 - Adelhelm, Philipp
A1 - Chen, Yawei
A1 - Xu, Liang
A1 - Yu, Peiping
A1 - Kim, Junghwa
A1 - Kochovski, Zdravko
A1 - Yu, Zhilong
A1 - Li, Wanxia
A1 - LeBeau, James
A1 - Shao-Horn, Yang
A1 - Cao, Ruiguo
A1 - Jiao, Shuhong
A1 - Cheng, Tao
A1 - Manke, Ingo
A1 - Lu, Yan
T1 - Promoting mechanistic understanding of lithium deposition and solid-electrolyte interphase (SEI) formation using advanced characterization and simulation methods: recent progress, limitations, and future perspectives
JF - Avanced energy materials
N2 - In recent years, due to its great promise in boosting the energy density of lithium batteries for future energy storage, research on the Li metal anode, as an alternative to the graphite anode in Li-ion batteries, has gained significant momentum. However, the practical use of Li metal anodes has been plagued by unstable Li (re)deposition and poor cyclability. Although tremendous efforts have been devoted to the stabilization of Li metal anodes, the mechanisms of electrochemical (re-)deposition/dissolution of Li and solid-electrolyte-interphase (SEI) formation remain elusive. This article highlights the recent mechanistic understandings and observations of Li deposition/dissolution and SEI formation achieved from advanced characterization techniques and simulation methods, and discusses major limitations and open questions in these processes. In particular, the authors provide their perspectives on advanced and emerging/potential methods for obtaining new insights into these questions. In addition, they give an outlook into cutting-edge interdisciplinary research topics for Li metal anodes. It pushes beyond the current knowledge and is expected to accelerate development toward a more in-depth and comprehensive understanding, in order to guide future research on Li metal anodes toward practical application.
KW - advanced characterization
KW - Li deposition
KW - Li dissolution
KW - Li metal
KW - anodes
KW - mechanistic understanding
KW - solid-electrolyte-interphase
KW - theoretical simulation
Y1 - 2022
U6 - https://doi.org/10.1002/aenm.202200398
SN - 1614-6832
SN - 1614-6840
VL - 12
IS - 19
PB - Wiley
CY - Weinheim
ER -
TY - JOUR
A1 - Mayer, Dennis
A1 - Lever, Fabiano
A1 - Picconi, David
A1 - Metje, Jan
A1 - Ališauskas, Skirmantas
A1 - Calegari, Francesca
A1 - Düsterer, Stefan
A1 - Ehlert, Christopher
A1 - Feifel, Raimund
A1 - Niebuhr, Mario
A1 - Manschwetus, Bastian
A1 - Kuhlmann, Marion
A1 - Mazza, Tommaso
A1 - Robinson, Matthew Scott
A1 - Squibb, Richard J.
A1 - Trabattoni, Andrea
A1 - Wallner, Måns
A1 - Saalfrank, Peter
A1 - Wolf, Thomas J. A.
A1 - Gühr, Markus
T1 - Following excited-state chemical shifts in molecular ultrafast x-ray photoelectron spectroscopy
JF - Nature communications
N2 - Imaging the charge flow in photoexcited molecules would provide key information on photophysical and photochemical processes. Here the authors demonstrate tracking in real time after photoexcitation the change in charge density at a specific site of 2-thiouracil using time-resolved X-ray photoelectron spectroscopy. The conversion of photon energy into other energetic forms in molecules is accompanied by charge moving on ultrafast timescales. We directly observe the charge motion at a specific site in an electronically excited molecule using time-resolved x-ray photoelectron spectroscopy (TR-XPS). We extend the concept of static chemical shift from conventional XPS by the excited-state chemical shift (ESCS), which is connected to the charge in the framework of a potential model. This allows us to invert TR-XPS spectra to the dynamic charge at a specific atom. We demonstrate the power of TR-XPS by using sulphur 2p-core-electron-emission probing to study the UV-excited dynamics of 2-thiouracil. The method allows us to discover that a major part of the population relaxes to the molecular ground state within 220-250 fs. In addition, a 250-fs oscillation, visible in the kinetic energy of the TR-XPS, reveals a coherent exchange of population among electronic states.
Y1 - 2022
U6 - https://doi.org/10.1038/s41467-021-27908-y
SN - 2041-1723
N1 - Publisher correction: https://doi.org/10.1038/s41467-022-28584-2
VL - 13
IS - 1
PB - Nature Research
CY - Berlin
ER -
TY - JOUR
A1 - Ning, Jiaoyi
A1 - Yu, Hongtao
A1 - Mei, Shilin
A1 - Schütze, Yannik
A1 - Risse, Sebastian
A1 - Kardjilov, Nikolay
A1 - Hilger, André
A1 - Manke, Ingo
A1 - Bande, Annika
A1 - Ruiz, Victor G.
A1 - Dzubiella, Joachim
A1 - Meng, Hong
A1 - Lu, Yan
T1 - Constructing binder- and carbon additive-free organosulfur cathodes based on conducting thiol-polymers through electropolymerization for lithium-sulfur batteries
JF - ChemSusChem
N2 - Herein, the concept of constructing binder- and carbon additive-free organosulfur cathode was proved based on thiol-containing conducting polymer poly(4-(thiophene-3-yl) benzenethiol) (PTBT). The PTBT featured the polythiophene-structure main chain as a highly conducting framework and the benzenethiol side chain to copolymerize with sulfur and form a crosslinked organosulfur polymer (namely S/PTBT). Meanwhile, it could be in-situ deposited on the current collector by electro-polymerization, making it a binder-free and free-standing cathode for Li-S batteries. The S/PTBT cathode exhibited a reversible capacity of around 870 mAh g(-1) at 0.1 C and improved cycling performance compared to the physically mixed cathode (namely S&PTBT). This multifunction cathode eliminated the influence of the additives (carbon/binder), making it suitable to be applied as a model electrode for operando analysis. Operando X-ray imaging revealed the remarkable effect in the suppression of polysulfides shuttle via introducing covalent bonds, paving the way for the study of the intrinsic mechanisms in Li-S batteries.
KW - electrochemistry
KW - energy storage
KW - lithium-sulfur batteries
KW - operando
KW - studies
KW - organosulfur
Y1 - 2022
U6 - https://doi.org/10.1002/cssc.202200434
SN - 1864-5631
SN - 1864-564X
VL - 15
IS - 14
PB - Wiley
CY - Weinheim
ER -
TY - JOUR
A1 - Neusser, David
A1 - Sun, Bowen
A1 - Tan, Wen Liang
A1 - Thomsen, Lars
A1 - Schultz, Thorsten
A1 - Perdigon-Toro, Lorena
A1 - Koch, Norbert
A1 - Shoaee, Safa
A1 - McNeill, Christopher R.
A1 - Neher, Dieter
A1 - Ludwigs, Sabine
T1 - Spectroelectrochemically determined energy levels of PM6:Y6 blends and their relevance to solar cell performance
JF - Journal of materials chemistry : C, Materials for optical and electronic devices
N2 - Recent advances in organic solar cell performance have been mainly driven forward by combining high-performance p-type donor-acceptor copolymers (e.g.PM6) and non-fullerene small molecule acceptors (e.g.Y6) as bulk-heterojunction layers. A general observation in such devices is that the device performance, e.g., the open-circuit voltage, is strongly dependent on the processing solvent. While the morphology is a typically named key parameter, the energetics of donor-acceptor blends are equally important, but less straightforward to access in the active multicomponent layer. Here, we propose to use spectral onsets during electrochemical cycling in a systematic spectroelectrochemical study of blend films to access the redox behavior and the frontier orbital energy levels of the individual compounds. Our study reveals that the highest occupied molecular orbital offset (Delta E-HOMO) in PM6:Y6 blends is similar to 0.3 eV, which is comparable to the binding energy of Y6 excitons and therefore implies a nearly zero driving force for the dissociation of Y6 excitons. Switching the PM6 orientation in the blend films from face-on to edge-on in bulk has only a minor influence on the positions of the energy levels, but shows significant differences in the open circuit voltage of the device. We explain this phenomenon by the different interfacial molecular orientations, which are known to affect the non-radiative decay rate of the charge-transfer state. We compare our results to ultraviolet photoelectron spectroscopy data, which shows distinct differences in the HOMO offsets in the PM6:Y6 blend compared to neat films. This highlights the necessity to measure the energy levels of the individual compounds in device-relevant blend films.
Y1 - 2022
U6 - https://doi.org/10.1039/d2tc01918c
SN - 2050-7526
SN - 2050-7534
VL - 10
IS - 32
SP - 11565
EP - 11578
PB - Royal Society of Chemistry
CY - Cambridge
ER -
TY - JOUR
A1 - Stefancu, Andrei
A1 - Nan, Lin
A1 - Zhu, Li
A1 - Chis, Vasile
A1 - Bald, Ilko
A1 - Liu, Min
A1 - Leopold, Nicolae
A1 - Maier, Stefan A.
A1 - Cortes, Emiliano
T1 - Controlling plasmonic chemistry pathways through specific ion effects
JF - Advanced optical materials
N2 - Plasmon-driven dehalogenation of brominated purines has been recently explored as a model system to understand fundamental aspects of plasmon-assisted chemical reactions. Here, it is shown that divalent Ca2+ ions strongly bridge the adsorption of bromoadenine (Br-Ade) to Ag surfaces.
Such ion-mediated binding increases the molecule's adsorption energy leading to an overlap of the metal energy states and the molecular states, enabling the chemical interface damping (CID) of the plasmon modes of the Ag nanostructures (i.e., direct electron transfer from the metal to Br-Ade).
Consequently, the conversion of Br-Ade to adenine almost doubles following the addition of Ca2+.
These experimental results, supported by theoretical calculations of the local density of states of the Ag/Br-Ade complex, indicate a change of the charge transfer pathway driving the dehalogenation reaction, from Landau damping (in the lack of Ca2+ ions) to CID (after the addition of Ca2+).
The results show that the surface dynamics of chemical species (including water molecules) play an essential role in charge transfer at plasmonic interfaces and cannot be ignored. It is envisioned that these results will help in designing more efficient nanoreactors, harnessing the full potential of plasmon-assisted chemistry.
KW - chemical interface damping
KW - Hofmeister effect
KW - hydration layer
KW - plasmonic chemistry
KW - specific ion effects
KW - surface-enhanced Raman scattering
Y1 - 2022
U6 - https://doi.org/10.1002/adom.202200397
SN - 2195-1071
VL - 10
IS - 14
PB - Wiley-VCH
CY - Weinheim
ER -
TY - JOUR
A1 - Michaelis, Vivien
A1 - Aengenheister, Leonie
A1 - Tuchtenhagen, Max
A1 - Rinklebe, Jörg
A1 - Ebert, Franziska
A1 - Schwerdtle, Tanja
A1 - Buerki-Thurnherr, Tina
A1 - Bornhorst, Julia
T1 - Differences and interactions in placental manganese and iron transfer across an in vitro model of human villous trophoblasts
JF - International journal of molecular sciences
N2 - Manganese (Mn) as well as iron (Fe) are essential trace elements (TE) important for the maintenance of physiological functions including fetal development. However, in the case of Mn, evidence suggests that excess levels of intrauterine Mn are associated with adverse pregnancy outcomes. Although Mn is known to cross the placenta, the fundamentals of Mn transfer kinetics and mechanisms are largely unknown. Moreover, exposure to combinations of TEs should be considered in mechanistic transfer studies, in particular for TEs expected to share similar transfer pathways. Here, we performed a mechanistic in vitro study on the placental transfer of Mn across a BeWo b30 trophoblast layer. Our data revealed distinct differences in the placental transfer of Mn and Fe. While placental permeability to Fe showed a clear inverse dose-dependency, Mn transfer was largely independent of the applied doses. Concurrent exposure of Mn and Fe revealed transfer interactions of Fe and Mn, indicating that they share common transfer mechanisms. In general, mRNA and protein expression of discussed transporters like DMT1, TfR, or FPN were only marginally altered in BeWo cells despite the different exposure scenarios highlighting that Mn transfer across the trophoblast layer likely involves a combination of active and passive transport processes.
KW - manganese
KW - iron
KW - placental transfer
KW - TE interactions
KW - BeWo b30
KW - trophoblasts
Y1 - 2022
U6 - https://doi.org/10.3390/ijms23063296
SN - 1422-0067
VL - 23
IS - 6
PB - MDPI
CY - Basel
ER -
TY - GEN
A1 - Bande, Annika
A1 - González, Leticia
A1 - Klamroth, Tillmann
A1 - Tremblay, Jean Christophe
T1 - Theoretical chemistry and quantum dynamics at interfaces
BT - Celebrating the career of Peter Saalfrank on the occasion of his 60th birthday
T2 - Chemical physics : a journal devoted to experimental and theoretical research involving problems of both a chemical and physical nature
Y1 - 2022
U6 - https://doi.org/10.1016/j.chemphys.2022.111509
SN - 0301-0104
SN - 1873-4421
VL - 558
PB - Elsevier Science
CY - Amsterdam [u.a.]
ER -
TY - JOUR
A1 - Crovetto, Andrea
A1 - Kojda, Danny
A1 - Yi, Feng
A1 - Heinselman, Karen N.
A1 - LaVan, David A.
A1 - Habicht, Klaus
A1 - Unold, Thomas
A1 - Zakutayev, Andriy
T1 - Crystallize It before It diffuses
BT - kinetic stabilization of thin-film phosphorus-rich semiconductor CuP2
JF - Journal of the american chemical society
N2 - Numerous phosphorus-rich metal phosphides containing both P-P bonds and metal-P bonds are known from the solid-state chemistry literature. A method to grow these materials in thin-film form would be desirable, as thin films are required in many applications and they are an ideal platform for high-throughput studies. In addition, the high density and smooth surfaces achievable in thin films are a significant advantage for characterization of transport and optical properties. Despite these benefits, there is hardly any published work on even the simplest binary phosphorus-rich phosphide films. Here, we demonstrate growth of single-phase CuP2 films by a two-step process involving reactive sputtering of amorphous CuP2+x and rapid annealing in an inert atmosphere. At the crystallization temperature, CuP2 is thermodynamically unstable with respect to Cu3P and P-4. However, CuP2 can be stabilized if the amorphous precursors are mixed on the atomic scale and are sufficiently close to the desired composition (neither too P poor nor too P rich). Fast formation of polycrystalline CuP2, combined with a short annealing time, makes it possible to bypass the diffusion processes responsible for decomposition. We find that thin-film CuP2 is a 1.5 eV band gap semiconductor with interesting properties, such as a high optical absorption coefficient (above 10(5) cm(-1)), low thermal conductivity (1.1 W/(K m)), and composition-insensitive electrical conductivity (around 1 S/cm). We anticipate that our processing route can be extended to other phosphorus-rich phosphides that are still awaiting thin-film synthesis and will lead to a more complete understanding of these materials and of their potential applications.
Y1 - 2022
U6 - https://doi.org/10.1021/jacs.2c04868
SN - 0002-7863
SN - 1520-5126
VL - 144
IS - 29
SP - 13334
EP - 13343
PB - American Chemical Society
CY - Washington
ER -
TY - JOUR
A1 - Tung, Wing Tai
A1 - Maring, Janita A.
A1 - Xu, Xun
A1 - Liu, Yue
A1 - Becker, Matthias
A1 - Somesh, Dipthi Bachamanda
A1 - Klose, Kristin
A1 - Wang, Weiwei
A1 - Sun, Xianlei
A1 - Ullah, Imran
A1 - Kratz, Karl
A1 - Neffe, Axel T.
A1 - Stamm, Christof
A1 - Ma, Nan
A1 - Lendlein, Andreas
T1 - In vivo performance of a cell and factor free multifunctional fiber mesh modulating postinfarct myocardial remodeling
JF - Advanced Functional Materials
N2 - Guidance of postinfarct myocardial remodeling processes by an epicardial patch system may alleviate the consequences of ischemic heart disease. As macrophages are highly relevant in balancing immune response and regenerative processes their suitable instruction would ensure therapeutic success. A polymeric mesh capable of attracting and instructing monocytes by purely physical cues and accelerating implant degradation at the cell/implant interface is designed. In a murine model for myocardial infarction the meshes are compared to those either coated with extracellular matrix or loaded with induced cardiomyocyte progenitor cells. All implants promote macrophage infiltration and polarization in the epicardium, which is verified by in vitro experiments. 6 weeks post-MI, especially the implantation of the mesh attenuates left ventricular adverse remodeling processes as shown by reduced infarct size (14.7% vs 28-32%) and increased wall thickness (854 mu m vs 400-600 mu m), enhanced angiogenesis/arteriogenesis (more than 50% increase compared to controls and other groups), and improved heart function (ejection fraction = 36.8% compared to 12.7-31.3%). Upscaling as well as process controls is comprehensively considered in the presented mesh fabrication scheme to warrant further progression from bench to bedside.
KW - bioinstructive materials
KW - cardiac regeneration
KW - function by structure;
KW - modulation of in vivo regeneration
KW - multifunctional biomaterials
Y1 - 2022
U6 - https://doi.org/10.1002/adfm.202110179
SN - 1616-301X
SN - 1616-3028
VL - 32
IS - 31
PB - Wiley
CY - Weinheim
ER -
TY - JOUR
A1 - Mei, Shilin
A1 - Siebert, Andreas
A1 - Xu, Yaolin
A1 - Quan, Ting
A1 - Garcia-Diez, Raul
A1 - Bär, Marcus
A1 - Härtel, Paul
A1 - Abendroth, Thomas
A1 - Dörfler, Susanne
A1 - Kaskel, Stefan
A1 - Lu, Yan
T1 - Large-Scale Synthesis of Nanostructured Carbon-Ti4O7 Hollow Particles as Efficient Sulfur Host Materials for Multilayer Lithium-Sulfur Pouch Cells
JF - Batteries & supercaps
N2 - Applications of advanced cathode materials with well-designed chemical components and/or optimized nanostructures promoting the sulfur redox kinetics and suppressing the shuttle effect of polysulfides are highly valued. However, in the case of actual lithium-sulfur (Li-S) batteries under practical working conditions, one long-term obstacle still exists, which is mainly due to the difficulties in massive synthesis of such nanomaterials with low cost and ease of control on the nanostructure. Herein, we develop a facile synthesis of carbon coated Ti4O7 hollow nanoparticles (Ti4O7) using spherical polymer electrolyte brush as soft template, which is scalable via utilizing a minipilot reactor. The C Ti4O7 hollow nanoparticles provide strong chemical adsorption to polysulfides through the large polar surface and additional physical confinement by rich micro- & mesopores and have successfully been employed as an efficient sulfur host for multilayer pouch cells. Besides, the sluggish kinetics of the sulfur and lithium sulfide redox mechanism can be improved by the highly conductive Ti4O7 via catalyzation of the conversion of polysulfides. Consequently, the C-Ti4O7 based pouch cell endows a high discharge capacity of 1003 mAhg(-1) at 0.05 C, a high-capacity retention of 83.7% after 100 cycles at 0.1 C, and a high Coulombic efficiency of 97.5% at the 100th cycle. This work proposes an effective approach to transfer the synthesis of hollow Ti4O7 nanoparticles from lab- to large-scale production, paving the way to explore a wide range of advanced nanomaterials for multilayer Li-S pouch cells.
KW - lithium-sulfur batteries
KW - pouch cell
KW - spherical polyelectrolyte brushes (SPB)
KW - Ti4O7
Y1 - 2022
U6 - https://doi.org/10.1002/batt.202100398
SN - 2566-6223
VL - 5
IS - 6
PB - Wiley-VCH
CY - Weinheim
ER -
TY - JOUR
A1 - Lepre, Enrico
A1 - Heske, Julian
A1 - Nowakowski, Michal
A1 - Scoppola, Ernesto
A1 - Zizak, Ivo
A1 - Heil, Tobias
A1 - Kühne, Thomas D.
A1 - Antonietti, Markus
A1 - Lopez-Salas, Nieves
A1 - Albero, Josep
T1 - Ni-based electrocatalysts for unconventional CO2 reduction reaction to formic acid
JF - Nano energy
N2 - Electrochemical reduction stands as an alternative to revalorize CO2. Among the different alternatives, Ni single atoms supported on carbonaceous materials are an appealing catalytic solution due to the low cost and versatility of the support and the optimal usage of Ni and its predicted selectivity and efficiency (ca. 100% towards CO). Herein, we have used noble carbonaceous support derived from cytosine to load Ni subnanometric sites. The large heteroatom content of the support allows the stabilization of up to 11 wt% of Ni without the formation of nanoparticles through a simple impregnation plus calcination approach, where nickel promotes the stabilization of C3NOx frameworks and the oxidative support promotes a high oxidation state of nickel. EXAFS analysis points at nickel single atoms or subnanometric clusters coordinated by oxygen in the material surface. Unlike the wellknown N-coordinated Ni single sites selectivity towards CO2 reduction, O-coordinated-Ni single sites (ca. 7 wt% of Ni) reduced CO2 to CO, but subnanometric clusters (11 wt% of Ni) foster the unprecedented formation of HCOOH with 27% Faradaic efficiency at - 1.4 V. Larger Ni amounts ended up on the formation of NiO nanoparticles and almost 100% selectivity towards hydrogen evolution.
KW - CO 2 reduction reaction
KW - Noble carbon
KW - Ni-O4 electrocatalysts
KW - Formic acid
Y1 - 2022
U6 - https://doi.org/10.1016/j.nanoen.2022.107191
SN - 2211-2855
SN - 2211-3282
VL - 97
PB - Elsevier
CY - Amsterdam
ER -
TY - JOUR
A1 - Pham, Duong Tung
A1 - Quan, Ting
A1 - Mei, Shilin
A1 - Lu, Yan
T1 - Colloidal metal sulfide nanoparticles for high performance electrochemical energy storage systems
JF - Current opinion in green and sustainable chemistry
N2 - Transition metal sulfides have emerged as excellent replacement candidates of traditional insertion electrode materials based on their conversion or alloying mechanisms, facilitating high specific capacity and rate ability. However, parasitic reactions such as massive volume change during the discharge/ charge processes, intermediate polysulfide dissolution, and passivating solid electrolyte interface formation have led to poor cyclability, hindering their feasibility and applicability in energy storage systems. Colloidal metal sulfide nanoparticles, a special class that integrates the intrinsic chemical properties of metal sulfides and their specified structural features, have fairly enlarged their contribution due to the synergistic effect. This review highlights the latest synthetic approaches based on colloidal process. Their corresponding electrochemical outcomes will also be discussed, which are thoroughly updated along with their insight scientific standpoints.
Y1 - 2022
U6 - https://doi.org/10.1016/j.cogsc.2022.100596
SN - 2452-2236
VL - 34
PB - Elsevier
CY - Amsterdam
ER -
TY - JOUR
A1 - Pessanha, Tatiana
A1 - Paschoalino, Waldemir J.
A1 - Deroco, Patricia B.
A1 - Kogikoski Junior, Sergio
A1 - Moraes, Ana C. M. de
A1 - Carvalho Castro de Silva, Cecilia de
A1 - Kubota, Lauro T.
T1 - Interfacial capacitance of graphene oxide films electrodes
BT - Fundamental studies on electrolytes interface aiming (bio)sensing applications
JF - Electroanalysis : an internatinal journal devoted to electroanalysis, sensors and bioelectronic devices
N2 - The understanding of bidimensional materials dynamics and its electrolyte interface equilibrium, such as graphene oxide (GO), is critical for the development of a capacitive biosensing platform. The interfacial capacitance (C-i) of graphene-based materials may be tuned by experimental conditions such as pH optimization and cation size playing key roles at the enhancement of their capacitive properties allowing their application as novel capacitive biosensors. Here we reported a systematic study of C-i of multilayer GO films in different aqueous electrolytes employing electrochemical impedance spectroscopy for the application in a capacitive detection system. We demonstrated that the presence of ionizable oxygen-containing functional groups within multilayer GO film favors the interactions and the accumulation of cations in the structure of the electrodes enhancing the GO C-i in aqueous solutions, where at pH 7.0 (the best condition) the C-i was 340 mu F mg(-1) at -0.01 V vs Ag/AgCl. We also established that the hydrated cation radius affects the mobility and interaction with GO functional groups and it plays a critical role in the Ci, as demonstrated in the presence of different cations Na+=640 mu F mg(-1), Li+=575 mu F mg(-1) and TMA(+)=477 mu F mg(-1). As a proof-of-concept, the capacitive behaviour of GO was explored as biosensing platform for standard streptavidin-biotin systems. For this system, the C-i varied linearly with the log of the concentration of the targeting analyte in the range from 10 pg mL(-1) to 100 ng mL(-1), showing the promising applicability of capacitive GO based sensors for label-free biosensing.
KW - Interfacial capacitance
KW - Graphene oxide
KW - Functional groups
KW - Electrochemical impedance
KW - Graphene derivates
Y1 - 2021
U6 - https://doi.org/10.1002/elan.202100220
SN - 1521-4109
SN - 1040-0397
VL - 34
IS - 4
SP - 692
EP - 700
PB - Wiley-VCH
CY - Weinheim
ER -
TY - JOUR
A1 - Wang, Peixi
A1 - Geiger, Christina
A1 - Kreuzer, Lucas
A1 - Widmann, Tobias
A1 - Reitenbach, Julija
A1 - Liang, Suzhe
A1 - Cubitt, Robert
A1 - Henschel, Cristiane
A1 - Laschewsky, André
A1 - Papadakis, Christine M.
A1 - Müller-Buschbaum, Peter
T1 - Poly(sulfobetaine)-based diblock copolymer thin films in water/acetone atmosphere: modulation of water hydration and co-nonsolvency-triggered film contraction
JF - Langmuir : the ACS journal of surfaces and colloids
N2 - The water swelling and subsequent solvent exchange including co-nonsolvency behavior of thin films of a doubly thermo-responsive diblock copolymer (DBC) are studied viaspectral reflectance, time-of-flight neutron reflectometry, and Fourier transform infrared spectroscopy.
The DBC consists of a thermo-responsive zwitterionic (poly(4-((3-methacrylamidopropyl) dimethylammonio) butane-1-sulfonate)) (PSBP) block, featuring an upper critical solution temperature transition in aqueous media but being insoluble in acetone, and a nonionic poly(N-isopropylmethacrylamide) (PNIPMAM) block, featuring a lower critical solution temperature transition in water, while being soluble in acetone.
Homogeneous DBC films of 50-100 nm thickness are first swollen in saturated water vapor (H2OorD2O), before they are subjected to a contraction process by exposure to mixed saturated water/acetone vapor (H2OorD2O/acetone-d6 = 9:1 v/v).
The affinity of the DBC film toward H2O is stronger than for D2O, as inferred from the higher film thickness in the swollen state and the higher absorbed water content, thus revealing a pronounced isotope sensitivity.
During the co-solvent-induced switching by mixed water/acetone vapor, a two-step film contraction is observed, which is attributed to the delayed expulsion of water molecules and uptake of acetone molecules.
The swelling kinetics are compared for both mixed vapors (H2O/acetone-d6 and D2O/acetone-d6) and with those of the related homopolymer films.
Moreover, the concomitant variations of the local environment around the hydrophilic groups located in the PSBP and PNIPMAM blocks are followed.
The first contraction step turns out to be dominated by the behavior of the PSBP block, where as the second one is dominated by the PNIPMAM block.
The unusual swelling and contraction behavior of the latter block is attributed to its co-nonsolvency behavior.
Furthermore, we observe cooperative hydration effects in the DBC films, that is, both polymer blocks influence each other's solvation behavior.
Y1 - 2022
U6 - https://doi.org/10.1021/acs.langmuir.2c00451
SN - 0743-7463
SN - 1520-5827
VL - 38
IS - 22
SP - 6934
EP - 6948
PB - American Chemical Society
CY - Washington
ER -
TY - JOUR
A1 - Kuntze, Kim
A1 - Viljakka, Jani
A1 - Titov, Evgenii
A1 - Ahmed, Zafar
A1 - Kalenius, Elina
A1 - Saalfrank, Peter
A1 - Priimagi, Arri
T1 - Towards low-energy-light-driven bistable photoswitches
BT - ortho-fluoroaminoazobenzenes
JF - Photochemical & photobiological sciences / European Society for Photobiology
N2 - Thermally stable photoswitches that are driven with low-energy light are rare, yet crucial for extending the applicability of photoresponsive molecules and materials towards, e.g., living systems. Combined ortho-fluorination and -amination couples high visible light absorptivity of o-aminoazobenzenes with the extraordinary bistability of o-fluoroazobenzenes. Herein, we report a library of easily accessible o-aminofluoroazobenzenes and establish structure-property relationships regarding spectral qualities, visible light isomerization efficiency and thermal stability of the cis-isomer with respect to the degree of o-substitution and choice of amino substituent. We rationalize the experimental results with quantum chemical calculations, revealing the nature of low-lying excited states and providing insight into thermal isomerization. The synthesized azobenzenes absorb at up to 600 nm and their thermal cis-lifetimes range from milliseconds to months. The most unique example can be driven from trans to cis with any wavelength from UV up to 595 nm, while still exhibiting a thermal cis-lifetime of 81 days.
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Y1 - 2022
U6 - https://doi.org/10.1007/s43630-021-00145-4
SN - 1474-905X
SN - 1474-9092
VL - 21
IS - 2
SP - 159
EP - 173
PB - Springer
CY - Heidelberg
ER -
TY - JOUR
A1 - Xie, Dongjiu
A1 - Xu, Yaolin
A1 - Wang, Yonglei
A1 - Pan, Xuefeng
A1 - Härk, Eneli
A1 - Kochovski, Zdravko
A1 - Eljarrat, Alberto
A1 - Müller, Johannes
A1 - Koch, Christoph T.
A1 - Yuan, Jiayin
A1 - Lu, Yan
T1 - Poly(ionic liquid) nanovesicle-templated carbon nanocapsules functionalized with uniform iron nitride nanoparticles as catalytic sulfur host for Li-S batteries
JF - ACS nano
N2 - Poly(ionic liquid)s (PIL) are common precursors for heteroatom-doped carbon materials. Despite a relatively higher carbonization yield, the PIL-to-carbon conversion process faces challenges in preserving morphological and structural motifs on the nanoscale. Assisted by a thin polydopamine coating route and ion exchange, imidazoliumbased PIL nanovesicles were successfully applied in morphology-maintaining carbonization to prepare carbon composite nanocapsules. Extending this strategy further to their composites, we demonstrate the synthesis of carbon composite nanocapsules functionalized with iron nitride nanoparticles of an ultrafine, uniform size of 3-5 nm (termed "FexN@C "). Due to its unique nanostructure, the sulfur-loaded FexN@C electrode was tested to efficiently mitigate the notorious shuttle effect of lithium polysulfides (LiPSs) in Li-S batteries. The cavity of the carbon nanocapsules was spotted to better the loading content of sulfur. The well-dispersed iron nitride nanoparticles effectively catalyze the conversion of LiPSs to Li2S, owing to their high electronic conductivity and strong binding power to LiPSs. Benefiting from this well-crafted composite nanostructure, the constructed FexN@C/S cathode demonstrated a fairly high discharge capacity of 1085 mAh g(-1) at 0.5 C initially, and a remaining value of 930 mAh g(-1 )after 200 cycles. In addition, it exhibits an excellent rate capability with a high initial discharge capacity of 889.8 mAh g(-1) at 2 C. This facile PIL-to-nanocarbon synthetic approach is applicable for the exquisite design of complex hybrid carbon nanostructures with potential use in electrochemical energy storage and conversion.
KW - poly(ionic liquid)s
KW - nanovesicles
KW - sulfur host
KW - iron nitride
KW - Li-S
KW - batteries
Y1 - 2022
U6 - https://doi.org/10.1021/acsnano.2c01992
SN - 1936-0851
SN - 1936-086X
VL - 16
IS - 7
SP - 10554
EP - 10565
PB - American Chemical Society
CY - Washington
ER -
TY - JOUR
A1 - Pan, Xuefeng
A1 - Sarhan, Radwan Mohamed
A1 - Kochovski, Zdravko
A1 - Chen, Guosong
A1 - Taubert, Andreas
A1 - Mei, Shilin
A1 - Lu, Yan
T1 - Template synthesis of dual-functional porous MoS2 nanoparticles with photothermal conversion and catalytic properties
JF - Nanoscale
N2 - Advanced catalysis triggered by photothermal conversion effects has aroused increasing interest due to its huge potential in environmental purification.
In this work, we developed a novel approach to the fast degradation of 4-nitrophenol (4-Nip) using porous MoS2 nanoparticles as catalysts, which integrate the intrinsic catalytic property of MoS2 with its photothermal conversion capability.
Using assembled polystyrene-b-poly(2-vinylpyridine) block copolymers as soft templates, various MoS 2 particles were prepared, which exhibited tailored morphologies (e.g., pomegranate-like, hollow, and open porous structures).
The photothermal conversion performance of these featured particles was compared under near-infrared (NIR) light irradiation.
Intriguingly, when these porous MoS2 particles were further employed as catalysts for the reduction of 4-Nip, the reaction rate constant was increased by a factor of 1.5 under NIR illumination.
We attribute this catalytic enhancement to the open porous architecture and light-to-heat conversion performance of the MoS2 particles. This contribution offers new opportunities for efficient photothermal-assisted catalysis.
Y1 - 2022
U6 - https://doi.org/10.1039/d2nr01040b
SN - 2040-3372
VL - 14
IS - 18
SP - 6888
EP - 6901
PB - RSC Publ. (Royal Society of Chemistry)
CY - Cambridge
ER -
TY - JOUR
A1 - Zhao, Yuhang
A1 - Sarhan, Radwan Mohamed
A1 - Eljarrat, Alberto
A1 - Kochovski, Zdravko
A1 - Koch, Christoph
A1 - Schmidt, Bernd
A1 - Koopman, Wouter-Willem Adriaan
A1 - Lu, Yan
T1 - Surface-functionalized Au-Pd nanorods with enhanced photothermal conversion and catalytic performance
JF - ACS applied materials & interfaces
N2 - Bimetallic nanostructures comprising plasmonic and catalytic components have recently emerged as a promising approach to generate a new type of photo-enhanced nanoreactors. Most designs however concentrate on plasmon-induced charge separation, leaving photo-generated heat as a side product.
This work presents a photoreactor based on Au-Pd nanorods with an optimized photothermal conversion, which aims to effectively utilize the photo-generated heat to increase the rate of Pd-catalyzed reactions. Dumbbell-shaped Au nanorods were fabricated via a seed-mediated growth method using binary surfactants. Pd clusters were selectively grown at the tips of the Au nanorods, using the zeta potential as a new synthetic parameter to indicate the surfactant remaining on the nanorod surface.
The photothermal conversion of the Au-Pd nanorods was improved with a thin layer of polydopamine (PDA) or TiO2.
As a result, a 60% higher temperature increment of the dispersion compared to that for bare Au rods at the same light intensity and particle density could be achieved.
The catalytic performance of the coated particles was then tested using the reduction of 4-nitrophenol as the model reaction. Under light, the PDA-coated Au-Pd nanorods exhibited an improved catalytic activity, increasing the reaction rate by a factor 3.
An analysis of the activation energy confirmed the photoheating effect to be the dominant mechanism accelerating the reaction. Thus, the increased photothermal heating is responsible for the reaction acceleration.
Interestingly, the same analysis shows a roughly 10% higher reaction rate for particles under illumination compared to under dark heating, possibly implying a crucial role of localized heat gradients at the particle surface.
Finally, the coating thickness was identified as an essential parameter determining the photothermal conversion efficiency and the reaction acceleration.
KW - Au-Pd nanorods
KW - PDA
KW - photothermal conversion
KW - surface plasmon
KW - 4-nitrophenol
Y1 - 2022
U6 - https://doi.org/10.1021/acsami.2c00221
SN - 1944-8244
SN - 1944-8252
VL - 14
IS - 15
SP - 17259
EP - 17272
PB - American Chemical Society
CY - Washington, DC
ER -
TY - JOUR
A1 - Floyd, Thomas G.
A1 - Song, Ji-Inn
A1 - Hapeshi, Alexia
A1 - Laroque, Sophie
A1 - Hartlieb, Matthias
A1 - Perrier, Sebastien
T1 - Bottlebrush copolymers for gene delivery: influence of architecture, charge density, and backbone length on transfection efficiency
JF - Journal of materials chemistry : B, materials for biology and medicine
N2 - The influence of polymer architecture of polycations on their ability to transfect mammalian cells is probed. Polymer bottle brushes with grafts made from partially hydrolysed poly(2-ethyl-2-oxazoline) are used while varying the length of the polymer backbone as well as the degree of hydrolysis (cationic charge content). Polyplex formation is investigated via gel electrophoresis, dye-displacement and dynamic light scattering. Bottle brushes show a superior ability to complex pDNA when compared to linear copolymers. Also, nucleic acid release was found to be improved by a graft architecture. Polyplexes based on bottle brush copolymers showed an elongated shape in transmission electron microscopy images. The cytotoxicity against mammalian cells is drastically reduced when a graft architecture is used instead of linear copolymers. Moreover, the best-performing bottle brush copolymer showed a transfection ability comparable with that of linear poly(ethylenimine), the gold standard of polymeric transfection agents, which is used as positive control. In combination with their markedly lowered cytotoxicity, cationic bottle brush copolymers are therefore shown to be a highly promising class of gene delivery vectors.
Y1 - 2022
U6 - https://doi.org/10.1039/d2tb00490a
SN - 2050-750X
SN - 2050-7518
VL - 10
IS - 19
SP - 3696
EP - 3704
PB - Royal Society of Chemistry
CY - London [u.a.]
ER -
TY - JOUR
A1 - Abbasi, Ali
A1 - Xu, Yaolin
A1 - Khezri, Ramin
A1 - Etesami, Mohammad
A1 - Lin, C.
A1 - Kheawhom, Soorathep
A1 - Lu, Yan
T1 - Advances in characteristics improvement of polymeric membranes/separators for zinc-air batteries
JF - Materials Today Sustainability
N2 - Zinc-air batteries (ZABs) are gaining popularity for a wide range of applications due to their high energy density, excellent safety, and environmental friendliness. A membrane/separator is a critical component of ZABs, with substantial implications for battery performance and stability, particularly in the case of a battery in solid state format, which has captured increased attention in recent years. In this review, recent advances as well as insight into the architecture of polymeric membrane/separators for ZABs including porous polymer separators (PPSs), gel polymer electrolytes (GPEs), solid polymer electrolytes (SPEs) and anion exchange membranes (AEMs) are discussed. The paper puts forward strategies to enhance stability, ionic conductivity, ionic selectivity, electrolyte storage capacity and mechanical properties for each type of polymeric membrane. In addition, the remaining major obstacles as well as the most potential avenues for future research are examined in detail.
KW - Ionic selectivity
KW - Ionic conductivity
KW - Gel polymer
KW - Ion exchange
KW - Porous
KW - polymer
Y1 - 2022
U6 - https://doi.org/10.1016/j.mtsust.2022.100126
SN - 2589-2347
VL - 18
PB - Elsevier
CY - Amsterdam
ER -
TY - JOUR
A1 - Mayer, Dennis
A1 - Picconi, David
A1 - Robinson, Matthew S.
A1 - Gühr, Markus
T1 - Experimental and theoretical gas-phase absorption spectra of thionated uracils
JF - Chemical physics : a journal devoted to experimental and theoretical research involving problems of both a chemical and physical nature
N2 - We present a comparative study of the gas-phase UV spectra of uracil and its thionated counterparts (2-thiouracil, 4-thiouracil and 2,4-dithiouracil), closely supported by time-dependent density functional theory calculations to assign the transitions observed. We systematically discuss pure gas-phase spectra for the (thio)uracils in the range of 200-400 nm (similar to 3.2-6.4 eV), and examine the spectra of all four species with a single theoretical approach. We note that specific vibrational modelling is needed to accurately determine the spectra across the examined wavelength range, and systematically model the transitions that appear at wavelengths shorter than 250 nm. Additionally, we find in the cases of 2-thiouracil and 2,4-dithiouracil, that the gas-phase spectra deviate significantly from some previously published solution-phase spectra, especially those collected in basic environments.
KW - Thiouracil
KW - Uracil
KW - UV-VIS Spectroscopy
KW - Excited-state calculations;
KW - TD-DFT
KW - Gas phase
Y1 - 2022
U6 - https://doi.org/10.1016/j.chemphys.2022.111500
SN - 0301-0104
VL - 558
PB - Elsevier
CY - Amsterdam
ER -
TY - JOUR
A1 - Ilic, Ivan
A1 - Schutjajew, Konstantin
A1 - Zhang, Wuyong
A1 - Oschatz, Martin
T1 - Changes of porosity of hard carbons during mechanical treatment and the relevance for sodium-ion anodes
JF - Carbon : an international journal sponsored by the American Carbon Society
N2 - Lithium-ion batteries have revolutionized battery technology. However, the scarcity of lithium in nature is driving the search for alternatives. For that reason, sodium-ion batteries have attracted increasing attention in recent years. The main obstacle to their development is the anode as, unlike for lithium-ion batteries, graphite cannot be used due to the inability to form stoichiometrically useful intercalation compounds with sodium. A promising candidate for sodium storage is hard carbon a form of nongraphitisable carbon, that can be synthesized from various precursor materials. Processing of hard carbons is often done by using mechanochemical treatments. Although it is generally accepted and often observed that they can influence the porosity of hard carbons, their effect on battery performance not well understood. Here, the changes in porosity occurring during ball milling are elucidated and related to the properties of hard carbons in sodium storage. Analysis by combined gas physisorption and small angle X-ray scattering shows that porosity changes during ball milling with a significant increase of the open porosity, unsuitable for reversible sodium storage, and decrease of the closed porosity, suitable for reversible sodium storage. While pristine hard carbon can store 58.5 mAh g(-1) in the closed pores, upon 5 h of mechanical treatment in a ball mill it can only store 35.5 mAh g(-1). The obtained results are furthermore pointing towards the disputed "intercalation-adsorption" mechanism.
KW - Hard carbons
KW - Sodium-ion batteries
KW - Anodes
KW - Microporosity
KW - Ball milling
Y1 - 2022
U6 - https://doi.org/10.1016/j.carbon.2021.09.063
SN - 0008-6223
SN - 1873-3891
VL - 186
SP - 55
EP - 63
PB - Elsevier Science
CY - Amsterdam [u.a.]
ER -
TY - JOUR
A1 - Gupta, Banshi D.
A1 - Pathak, Anisha
A1 - Shrivastav, Anand
T1 - Optical Biomedical Diagnostics Using Lab-on-Fiber Technology
BT - a review
JF - Photonics : open access journal
N2 - Point-of-care and in-vivo bio-diagnostic tools are the current need for the present critical scenarios in the healthcare industry. The past few decades have seen a surge in research activities related to solving the challenges associated with precise on-site bio-sensing. Cutting-edge fiber optic technology enables the interaction of light with functionalized fiber surfaces at remote locations to develop a novel, miniaturized and cost-effective lab on fiber technology for bio-sensing applications. The recent remarkable developments in the field of nanotechnology provide innumerable functionalization methodologies to develop selective bio-recognition elements for label free biosensors. These exceptional methods may be easily integrated with fiber surfaces to provide highly selective light-matter interaction depending on various transduction mechanisms. In the present review, an overview of optical fiber-based biosensors has been provided with focus on physical principles used, along with the functionalization protocols for the detection of various biological analytes to diagnose the disease. The design and performance of these biosensors in terms of operating range, selectivity, response time and limit of detection have been discussed. In the concluding remarks, the challenges associated with these biosensors and the improvement required to develop handheld devices to enable direct target detection have been highlighted.
KW - fiber optic sensors
KW - synthesis
KW - interferometry
KW - fluorescence
KW - SERS
KW - SPR
KW - immunosensors
KW - enzymatic sensors
KW - molecular imprinted polymers
Y1 - 2022
U6 - https://doi.org/10.3390/photonics9020086
SN - 2304-6732
VL - 9
IS - 2
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Yue, Yanhua
A1 - Melani, Giacomo
A1 - Kirsch, Harald
A1 - Paarmann, Alexander
A1 - Saalfrank, Peter
A1 - Campen, Richard Kramer
A1 - Tong, Yujin
T1 - Structure and Reactivity of a-Al2O3(0001) Surfaces: How Do Al-I and Gibbsite-like Terminations Interconvert?
JF - The journal of physical chemistry / publ. weekly by the American Chemical Society. C, Energy, materials, and catalysis
N2 - The alpha-Al2O3(0001) surface has been extensively studied because of its significance in both fundamental research and application. Prior work suggests that in ultra-high-vacuum (UHV), in the absence of water, the so-called Al-I termination is thermodynamically favored, while in ambient, in contact with liquid water, a Gibbsite-like layer is created. While the view of the alpha- Al2O3(0001)/H2O(l) interface appears relatively clear in theory, experimental characterization of this system has resulted in estimates of surface acidity, i.e., isoelectric points, that differ by 4 pH units and surface structure that in some reports has non-hydrogen-bonded surface aluminol (Al-OH) groups and in others does not. In this study, we employed vibrational sum frequency spectroscopy (VSFS) and density functional theory (DFT) simulation to study the surface phonon modes of the differently terminated alpha-Al2O3(0001) surfaces in both UHV and ambient. We find that, on either water dosing of the Al-I in UHV or heat-induced dehydroxylation of the Gibbsite-like in ambient, the surfaces do not interconvert. This observation offers a new explanation for disagreements in prior work on the alpha-Al2O3(0001)/liquid water interface -different preparation methods may create surfaces that do not interconvert-and shows that the surface phonon spectral response offers a novel probe of interfacial hydrogen bonding structure.
Y1 - 2022
U6 - https://doi.org/10.1021/acs.jpcc.2c03743
SN - 1932-7447
SN - 1932-7455
VL - 126
IS - 31
SP - 13467
EP - 13476
PB - American Chemical Society
CY - Washington
ER -
TY - JOUR
A1 - Tarazona Lizcano, Natalia Andrea
A1 - Machatschek, Rainhard Gabriel
A1 - Balcucho, Jennifer
A1 - Castro-Mayorga, Jinneth Lorena
A1 - Saldarriaga, Juan Francisco
A1 - Lendlein, Andreas
T1 - Opportunities and challenges for integrating the development of sustainable polymer materials within an international circular (bio)economy concept
JF - MRS energy & sustainability : science & technology & socio-economics & policy
N2 - The production and consumption of commodity polymers have been an indispensable part of the development of our modern society. Owing to their adjustable properties and variety of functions, polymer-based materials will continue playing important roles in achieving the Sustainable Development Goals (SDG)s, defined by the United Nations, in key areas such as healthcare, transport, food preservation, construction, electronics, and water management. Considering the serious environmental crisis, generated by increasing consumption of plastics, leading-edge polymers need to incorporate two types of functions: Those that directly arise from the demands of the application (e.g. selective gas and liquid permeation, actuation or charge transport) and those that enable minimization of environmental harm, e.g., through prolongation of the functional lifetime, minimization of material usage, or through predictable disintegration into non-toxic fragments. Here, we give examples of how the incorporation of a thoughtful combination of properties/functions can enhance the sustainability of plastics ranging from material design to waste management. We focus on tools to measure and reduce the negative impacts of plastics on the environment throughout their life cycle, the use of renewable sources for their synthesis, the design of biodegradable and/or recyclable materials, and the use of biotechnological strategies for enzymatic recycling of plastics that fits into a circular bioeconomy. Finally, we discuss future applications for sustainable plastics with the aim to achieve the SDGs through international cooperation.
Leading-edge polymer-based materials for consumer and advanced applications are necessary to achieve sustainable development at a global scale. It is essential to understand how sustainability can be incorporated in these materials via green chemistry, the integration of bio-based building blocks from biorefineries, circular bioeconomy strategies, and combined smart and functional capabilities.
KW - biomaterial
KW - degradable
KW - functional
KW - life cycle assessment
KW - renewable
KW - sustainability
Y1 - 2022
U6 - https://doi.org/10.1557/s43581-021-00015-7
SN - 2329-2229
SN - 2329-2237
VL - 9
IS - 1
SP - 28
EP - 34
PB - Springer Nature
CY - London
ER -
TY - JOUR
A1 - Mullan, Thomas
A1 - Maschio, Lorenzo
A1 - Saalfrank, Peter
A1 - Usvyat, Denis
T1 - Reaction barriers on non-conducting surfaces beyond periodic local MP2
BT - Diffusion of hydrogen on alpha-Al2O3 (0001) as a test case
JF - The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr
N2 - The quest for "chemical accuracy" is becoming more and more demanded in the field of structure and kinetics of molecules at solid surfaces. In this paper, as an example, we focus on the barrier for hydrogen diffusion on a alpha-Al2O3 (0001) surface, aiming for a couple cluster singles, doubles, and perturbative triples [CCSD(T)]-level benchmark. We employ the density functional theory (DFT) optimized minimum and transition state structures reported by Heiden, Usvyat, and Saalfrank [J. Phys. Chem. C 123, 6675 (2019)]. The barrier is first evaluated at the periodic Hartree-Fock and local Moller-Plesset second-order perturbation (MP2) level of theory. The possible sources of errors are then analyzed, which includes basis set incompleteness error, frozen core, density fitting, local approximation errors, as well as the MP2 method error. Using periodic and embedded fragment models, corrections to these errors are evaluated. In particular, two corrections are found to be non-negligible (both from the chemical accuracy perspective and at the scale of the barrier value of 0.72 eV): the correction to the frozen core-approximation of 0.06 eV and the CCSD(T) correction of 0.07 eV. Our correlated wave function results are compared to barriers obtained from DFT. Among the tested DFT functionals, the best performing for this barrier is B3LYP-D3.
Y1 - 2022
U6 - https://doi.org/10.1063/5.0082805
SN - 0021-9606
SN - 1089-7690
VL - 156
IS - 7
PB - AIP Publishing
CY - Melville
ER -
TY - JOUR
A1 - Hoffmann, Falk
A1 - Machatschek, Rainhard Gabriel
A1 - Lendlein, Andreas
T1 - Analytical model and Monte Carlo simulations of polymer degradation with improved chain cut statistics
JF - Journal of materials research : JMR
N2 - The degradation of polymers is described by mathematical models based on bond cleavage statistics including the decreasing probability of chain cuts with decreasing average chain length. We derive equations for the degradation of chains under a random chain cut and a chain end cut mechanism, which are compared to existing models. The results are used to predict the influence of internal molecular parameters. It is shown that both chain cut mechanisms lead to a similar shape of the mass or molecular mass loss curve. A characteristic time is derived, which can be used to extract the maximum length of soluble fragments l of the polymer. We show that the complete description is needed to extract the degradation rate constant k from the molecular mass loss curve and that l can be used to design polymers that lose less mechanical stability before entering the mass loss phase.
KW - Modeling
KW - Degradable
KW - Polymer
KW - Molecular weight
KW - Simulation
Y1 - 2022
U6 - https://doi.org/10.1557/s43578-022-00495-4
SN - 0884-2914
SN - 2044-5326
VL - 37
IS - 5
SP - 1093
EP - 1101
PB - Springer
CY - Heidelberg
ER -
TY - JOUR
A1 - Lau, Skadi
A1 - Gossen, Manfred
A1 - Lendlein, Andreas
A1 - Jung, Friedrich
T1 - Differential sensitivity of assays for determining vein endothelial cell senescence
JF - Clinical hemorheology and microcirculation : blood flow and vessels
N2 - In vivo endothelialization of polymer-based cardiovascular implant materials is a promising strategy to reduce the risk of platelet adherence and the subsequent thrombus formation and implant failure. However, endothelial cells from elderly patients are likely to exhibit a senescent phenotype that may counteract endothelialization. The senescence status of cells should therefore be investigated prior to implantation of devices designed to be integrated in the blood vessel wall. Here, human umbilical vein endothelial cells (HUVEC) were cultivated up to passage (P) 4, 10 and 26/27 to determine the population doubling time and the senescence status by four different methods. Determination of the senescence-associated beta-galactosidase activity (SA-beta-Gal) was carried out by colorimetric staining and microscopy (i), as well as by photometric quantification (ii), and the expression of senescence-associated nuclear proteins p16 and p21 as well as the proliferation marker Ki67 was assessed by immunostaining (iii), and by flow cytometry (iv). The population doubling time of P27-cells was remarkably greater (103 +/- 65 h) compared to P4-cells (24 +/- 3 h) and P10-cell (37 +/- 15 h). Among the four different methods tested, the photometric SA-beta-Gal activity assay and the flow cytometric determination of p16 and Ki67 were most effective in discriminating P27-cells from P4- and P10-cells. These methods combined with functional endothelial cell analyses might aid predictions on the performance of implant endothelialization in vivo.
KW - Ageing
KW - population doubling time
KW - senescence-associated
KW - beta-galactosidase
KW - cell cycle inhibitors
KW - p16
KW - p21
KW - Ki67
Y1 - 2022
U6 - https://doi.org/10.3233/CH-211294
SN - 1386-0291
SN - 1875-8622
VL - 81
IS - 3
SP - 191
EP - 203
PB - IOS Press
CY - Amsterdam
ER -
TY - JOUR
A1 - Tartivel, Lucile
A1 - Blocki, Anna M.
A1 - Braune, Steffen
A1 - Jung, Friedrich
A1 - Behl, Marc
A1 - Lendlein, Andreas
T1 - An Inverse shape-memory hydrogel scaffold switching upon cooling in a tissue-tolerated temperature range
JF - Advanced materials interfaces
N2 - Tissue reconstruction has an unmet need for soft active scaffolds that enable gentle loading with regeneration-directing bioactive components by soaking up but also provide macroscopic dimensional stability. Here microporous hydrogels capable of an inverse shape-memory effect (iSME) are described, which in contrast to classical shape-memory polymers (SMPs) recover their permanent shape upon cooling. These hydrogels are designed as covalently photo cross-linked polymer networks with oligo(ethylene glycol)-oligo(propylene glycol)-oligo(ethylene glycol) (OEG-OPG-OEG) segments. When heated after deformation, the OEG-OPG-OEG segments form micelles fixing the temporary shape. Upon cooling, the micelles dissociate again, the deformation is reversed and the permanent shape is obtained. Applicability of this iSME is demonstrated by the gentle loading of platelet-rich plasma (PRP) without causing any platelet activation during this process. PRP is highly bioactive and is widely acknowledged for its regenerative effects. Hence, the microporous inverse shape-memory hydrogel (iSMH) with a cooling induced pore-size effect represents a promising candidate scaffold for tissue regeneration for potential usage in minimally invasive surgery applications.
KW - active scaffold
KW - critical micellation temperature
KW - hydrogel
KW - inverse
KW - shape-memory effect
KW - platelet-rich plasma
Y1 - 2022
U6 - https://doi.org/10.1002/admi.202101588
SN - 2196-7350
VL - 9
IS - 6
PB - Wiley
CY - Hoboken
ER -
TY - JOUR
A1 - Tang, Jo Sing Julia
A1 - Smaczniak, Aline Debrassi
A1 - Tepper, Lucas
A1 - Rosencrantz, Sophia
A1 - Aleksanyan, Mina
A1 - Dähne, Lars
A1 - Rosencrantz, Ruben R.
T1 - Glycopolymer based LbL multilayer thin films with embedded liposomes
JF - Macromolecular bioscience
N2 - Layer-by-layer (LbL) self-assembly emerged as an efficient technique for fabricating coating systems for, e.g., drug delivery systems with great versatility and control. In this work, protecting group free and aqueous-based syntheses of bioinspired glycopolymer electrolytes aredescribed. Thin films of the glycopolymers are fabricated by LbL self-assembly and function as scaffolds for liposomes, which potentially can encapsulate active substances. The adsorbed mass, pH stability, and integrity of glycopolymer coatings as well as the embedded liposomes are investigated via whispering gallery mode (WGM) technology and quartz crystal microbalance with dissipation (QCM-D) monitoring , which enable label-free characterization. Glycopolymer thin films, with and without liposomes, are stable in the physiological pH range. QCM-D measurements verify the integrity of lipid vesicles. Thus, the fabrication of glycopolymer-based surface coatings with embedded and intact liposomes is presented.
KW - glycopolymers
KW - layer-by-layer self-assembly
KW - liposomes
KW - polyelectrolyte
KW - multilayer film
Y1 - 2022
U6 - https://doi.org/10.1002/mabi.202100461
SN - 1616-5187
SN - 1616-5195
VL - 22
IS - 4
PB - Wiley-VCH
CY - Weinheim
ER -
TY - JOUR
A1 - Abdou, Nicole
A1 - Alonso, Bruno
A1 - Brun, Nicolas
A1 - Landois, Perine
A1 - Taubert, Andreas
A1 - Hesemann, Peter
A1 - Mehdi, Ahmad
T1 - Ionic guest in ionic host
BT - ionosilica ionogel composites via ionic liquid confinement in ionosilica supports
JF - Materials chemistry frontiers
N2 - Ionosilica ionogels, i.e. composites consisting of an ionic liquid (IL) guest confined in an ionosilica host matrix, were synthesized via a non-hydrolytic sol-gel procedure from a tris-trialcoxysilylated amine precursor using the IL [BMIM]NTf2 as solvent. Various ionosilica ionogels were prepared starting from variable volumes of IL in the presence of formic acid. The resulting brittle and nearly colourless monoliths are composed of different amounts of IL guests confined in an ionosilica host as evidenced via thermogravimetric analysis, FT-IR, and C-13 CP-MAS solid-state NMR spectroscopy. In the following, we focused on confinement effects between the ionic host and guest. Special host-guest interactions between the IL guest and the ionosilica host were evidenced by H-1 solid-state NMR, Raman spectroscopy, and broadband dielectric spectroscopy (BDS) measurements. The three techniques indicate a strongly reduced ion mobility in the ionosilica ionogel composites containing small volume fractions of confined IL, compared to conventional silica-based ionogels. We conclude that the ionic ionosilica host stabilizes an IL layer on the host surface; this then results in a strongly reduced ion mobility compared to conventional silica hosts. The ion mobility progressively increases for systems containing higher volume fractions of IL and finally reaches the values observed in conventional silica based ionogels. These results therefore point towards strong interactions and confinement effects between the ionic host and the ionic guest on the ionosilica surface. Furthermore, this approach allows confining high volume fractions of IL into self-standing monoliths while preserving high ionic conductivity. These effects may be of interest in domains where IL phases must be anchored on solid supports to avoid leaching or IL spilling, e.g., in catalysis, in gas separation/sequestration devices or for the elaboration of solid electrolytes for (lithium-ion) batteries and supercapacitors.
Y1 - 2022
U6 - https://doi.org/10.1039/d2qm00021k
SN - 2052-1537
VL - 6
IS - 7
SP - 939
EP - 947
PB - Royal Society of Chemistry
CY - Cambridge
ER -
TY - JOUR
A1 - Bapolisi, Alain Murhimalika
A1 - Kielb, Patrycja
A1 - Bekir, Marek
A1 - Lehnen, Anne-Catherine
A1 - Radon, Christin
A1 - Laroque, Sophie
A1 - Wendler, Petra
A1 - Müller-Werkmeister, Henrike
A1 - Hartlieb, Matthias
T1 - Antimicrobial polymers of linear and bottlebrush architecture
BT - Probing the membrane interaction and physicochemical properties
JF - Macromolecular rapid communications : publishing the newsletters of the European Polymer Federation
N2 - Polymeric antimicrobial peptide mimics are a promising alternative for the future management of the daunting problems associated with antimicrobial resistance. However, the development of successful antimicrobial polymers (APs) requires careful control of factors such as amphiphilic balance, molecular weight, dispersity, sequence, and architecture. While most of the earlier developed APs focus on random linear copolymers, the development of APs with advanced architectures proves to be more potent. It is recently developed multivalent bottlebrush APs with improved antibacterial and hemocompatibility profiles, outperforming their linear counterparts. Understanding the rationale behind the outstanding biological activity of these newly developed antimicrobials is vital to further improving their performance. This work investigates the physicochemical properties governing the differences in activity between linear and bottlebrush architectures using various spectroscopic and microscopic techniques. Linear copolymers are more solvated, thermo-responsive, and possess facial amphiphilicity resulting in random aggregations when interacting with liposomes mimicking Escheria coli membranes. The bottlebrush copolymers adopt a more stable secondary conformation in aqueous solution in comparison to linear copolymers, conferring rapid and more specific binding mechanism to membranes. The advantageous physicochemical properties of the bottlebrush topology seem to be a determinant factor in the activity of these promising APs.
KW - antimicrobial polymers
KW - bottlebrush copolymers
KW - liposomes
KW - membrane
KW - interactions
KW - quartz crystal microbalance
Y1 - 2022
U6 - https://doi.org/10.1002/marc.202200288
SN - 1521-3927
SN - 1022-1336
VL - 43
IS - 19
PB - Wiley-VCH
CY - Weinheim
ER -
TY - JOUR
A1 - Kim, Jiyong
A1 - Kim, Yohan
A1 - Park, Kyoungwon
A1 - Boeffel, Christine
A1 - Choi, Hyung-Seok
A1 - Taubert, Andreas
A1 - Wedel, Armin
T1 - Ligand Effect in 1-Octanethiol Passivation of InP/ZnSe/ZnS Quantum Dots-Evidence of Incomplete Surface Passivation during Synthesis
JF - Small : nano micro
N2 - The lack of anionic carboxylate ligands on the surface of InP/ZnSe/ZnS quantum dots (QDs), where zinc carboxylate ligands can be converted to carboxylic acid or carboxylate ligands via proton transfer by 1-octanethiol, is demonstrated. The as-synthesized QDs initially have an under-coordinated vacancy surface, which is passivated by solvent ligands such as ethanol and acetone. Upon exposure of 1-octanethiol to the QD surface, 1-octanethiol effectively induces the surface binding of anionic carboxylate ligands (derived from zinc carboxylate ligands) by proton transfer, which consequently exchanges ethanol and acetone ligands that bind on the incomplete QD surface. These systematic chemical analyses, such as thermogravimetric analysis-mass spectrometry and proton nuclear magnetic resonance spectroscopy, directly show the interplay of surface ligands, and it associates with QD light-emitting diodes (QD-LEDs). It is believed that this better understanding can lead to industrially feasible QD-LEDs.
KW - colloidal quantum dots
KW - incomplete surface passivation
KW - indium
KW - phosphide
KW - surface chemistry
KW - thiol passivation
Y1 - 2022
U6 - https://doi.org/10.1002/smll.202203093
SN - 1613-6810
SN - 1613-6829
PB - Wiley-VCH
CY - Weinheim
ER -
TY - JOUR
A1 - Doering, Ulrike
A1 - Grigoriev, Dmitry
A1 - Tapio, Kosti
A1 - Bald, Ilko
A1 - Böker, Alexander
T1 - Synthesis of nanostructured protein-mineral-microcapsules by sonication
JF - Soft matter
N2 - We propose a simple and eco-friendly method for the formation of composite protein-mineral-microcapsules induced by ultrasound treatment. Protein- and nanoparticle-stabilized oil-in-water (O/W) emulsions loaded with different oils are prepared using high-intensity ultrasound. The formation of thin composite mineral proteinaceous shells is realized with various types of nanoparticles, which are pre-modified with Bovine Serum Albumin (BSA) and subsequently characterized by EDX, TGA, zeta potential measurements and Raman spectroscopy. Cryo-SEM and EDX mapping visualizations show the homogeneous distribution of the densely packed nanoparticles in the capsule shell. In contrast to the results reported in our previous paper,(1) the shell of those nanostructured composite microcapsules is not cross-linked by the intermolecular disulfide bonds between BSA molecules. Instead, a Pickering-Emulsion formation takes place because of the amphiphilicity-driven spontaneous attachment of the BSA-modified nanoparticles at the oil/water interface. Using colloidal particles for the formation of the shell of the microcapsules, in our case silica, hydroxyapatite and calcium carbonate nanoparticles, is promising for the creation of new functional materials. The nanoparticulate building blocks of the composite shell with different chemical, physical or morphological properties can contribute to additional, sometimes even multiple, features of the resulting capsules. Microcapsules with shells of densely packed nanoparticles could find interesting applications in pharmaceutical science, cosmetics or in food technology.
Y1 - 2022
U6 - https://doi.org/10.1039/d1sm01638e
SN - 1744-6848
VL - 18
IS - 13
SP - 2558
EP - 2568
PB - Royal Society of Chemistry
CY - London
ER -
TY - JOUR
A1 - Yang, Jin
A1 - Ghosh, Samrat
A1 - Roeser, Jérôme
A1 - Acharjya, Amitava
A1 - Penschke, Christopher
A1 - Tsutsui, Yusuke
A1 - Rabeah, Jabor
A1 - Wang, Tianyi
A1 - Tameu, Simon Yves Djoko
A1 - Ye, Meng-Yang
A1 - Grüneberg, Julia
A1 - Li, Shuang
A1 - Li, Changxia
A1 - Schomaecker, Reinhard
A1 - Van de Krol, Roel
A1 - Seki, Shu
A1 - Saalfrank, Peter
A1 - Thomas, Arne
T1 - Constitutional isomerism of the linkages in donor–acceptor covalent organic frameworks and its impact on photocatalysis
JF - Nature Communications
N2 - When new covalent organic frameworks (COFs) are designed, the main efforts are typically focused on selecting specific building blocks with certain geometries and properties to control the structure and function of the final COFs. The nature of the linkage (imine, boroxine, vinyl, etc.) between these building blocks naturally also defines their properties. However, besides the linkage type, the orientation, i.e., the constitutional isomerism of these linkages, has rarely been considered so far as an essential aspect. In this work, three pairs of constitutionally isomeric imine-linked donor-acceptor (D-A) COFs are synthesized, which are different in the orientation of the imine bonds (D-C=N-A (DCNA) and D-N=C-A (DNCA)). The constitutional isomers show substantial differences in their photophysical properties and consequently in their photocatalytic performance. Indeed, all DCNA COFs show enhanced photocatalytic H2 evolution performance than the corresponding DNCA COFs. Besides the imine COFs shown here, it can be concluded that the proposed concept of constitutional isomerism of linkages in COFs is quite universal and should be considered when designing and tuning the properties of COFs.
Y1 - 2022
U6 - https://doi.org/10.1038/s41467-022-33875-9
SN - 2041-1723
VL - 13
IS - 1
PB - Nature Publishing Group UK
CY - [London]
ER -
TY - JOUR
A1 - Zhang, Shanshan
A1 - Liu, Yue
A1 - Machatschek, Rainhard Gabriel
A1 - Lendlein, Andreas
T1 - Ultrathin collagen type I films formed at the air-water interface
JF - MRS advances : a journal of the Materials Research Society (MRS)
N2 - Collagen-based biomaterials with oriented fibrils have shown great application potential in medicine. However, it is still challenging to control the type I collagen fibrillogenesis in ultrathin films. Here, we report an approach to produce cohesive and well-organized type I collagen ultrathin films of about 10 nm thickness using the Langmuir-Blodgett technique. Ellipsometry, rheology, and Brewster angle microscopy are applied to investigate in situ how the molecules behave at the air-water interface, both at room temperature and 37 degrees C. The interfacial storage modulus observed at room temperature vanishes upon heating, indicating the existence and disappearance of the network structure in the protein nanosheet. The films were spanning over holes as large as 1 mm diameter when transferred at room temperature, proving the strong cohesive interactions. A highly aligned and fibrillar structure was observed by atomic force microscopy (AFM) and optical microscopy.
Y1 - 2022
U6 - https://doi.org/10.1557/s43580-021-00160-8
SN - 2059-8521
VL - 7
IS - 4
SP - 56
EP - 62
PB - Springer Nature Switzerland AG
CY - Cham
ER -
TY - JOUR
A1 - Roy, Parna
A1 - Mukherjee, Arpita
A1 - Mondal, Pritha
A1 - Bhattacharyya, Biswajit
A1 - Narayan, Awadhesh
A1 - Pandey, Anshu
T1 - Electronic structure and spectroscopy of I-III-VI2 nanocrystals
BT - a perspective
JF - The journal of physical chemistry : C, Nanomaterials and interfaces
N2 - I-III-VI2 semiconductor nanocrystals have been applied to a host of energy conversion devices with great success. Large scale implementation of device concepts based on these materials has, however, been somewhat stymied by the strong role of defects in determining the optoelectronic characteristics of these materials. Here we present a perspective view of the role of electronic structure and defects on the physical properties, particularly the spectroscopy, of this family of materials. Applications of these materials are further discussed in this context.
Y1 - 2022
U6 - https://doi.org/10.1021/acs.jpcc.1c10922
SN - 1932-7447
SN - 1932-7455
VL - 126
IS - 17
SP - 7364
EP - 7373
PB - American Chemical Society
CY - Washington
ER -
TY - JOUR
A1 - Madani, Amiera
A1 - Anghileri, Lucia
A1 - Heydenreich, Matthias
A1 - Möller, Heiko Michael
A1 - Pieber, Bartholomäus
T1 - Benzylic fluorination induced by a charge-transfer complex with a solvent-dependent selectivity switch
JF - Organic letters / publ. by the American Chemical Society
N2 - We present a divergent strategy for the fluorination of phenylacetic acid derivatives that is induced by a charge-transfer complex between Selectfluor and 4-(dimethylamino)pyridine. A comprehensive investigation of the conditions revealed a critical role of the solvent on the reaction outcome. In the presence of water, decarboxylative fluorination through a single-electron oxidation is dominant. Non-aqueous conditions result in the clean formation of alpha-fluoro-alpha-arylcarboxylic acids.
KW - Charge transfer
KW - Halogenation
KW - Oxidation
KW - Reaction products
KW - Reagents
Y1 - 2022
U6 - https://doi.org/10.1021/acs.orglett.2c02050
SN - 1523-7060
SN - 1523-7052
VL - 24
IS - 29
SP - 5376
EP - 5380
PB - American Chemical Society
CY - Washington
ER -
TY - JOUR
A1 - Mazarei, Elham
A1 - Barker, John R.
T1 - CH2 + O-2
BT - reaction mechanism, biradical and zwitterionic character, and formation of CH2OO, the simplest Criegee intermediate
JF - Physical chemistry, chemical physics : PCCP ; a journal of European Chemical Societies
N2 - The singlet and triplet potential surfaces for the title reaction were investigated using the CBS-QB3 level of theory. The wave functions for some species exhibited multireference character and required the CASPT2/6-31+G(d,p) and CASPT2/aug-cc-pVTZ levels of theory to obtain accurate relative energies. A Natural Bond Orbital Analysis showed that triplet (CH2OO)-C-3 (the simplest Criegee intermediate) and (CH2O2)-C-3 (dioxirane) have mostly polar biradical character, while singlet (CH2OO)-C-1 has some zwitterionic character and a planar structure. Canonical variational transition state theory (CVTST) and master equation simulations were used to analyze the reaction system. CVTST predicts that the rate constant for reaction of (CH2)-C-1 + O-3(2) is more than ten times as fast as the reaction of (CH2)-C-3 ((XB1)-B-3) + O-3(2) and the ratio remains almost independent of temperature from 900 K to 3000 K. The master equation simulations predict that at low pressures the (CH2O)-C-1 + O-3 product set is dominant at all temperatures and the primary yield of OH radicals is negligible below 600 K, due to competition with other primary reactions in this complex system.
Y1 - 2021
U6 - https://doi.org/10.1039/d1cp04372b
SN - 1463-9076
SN - 1463-9084
VL - 24
IS - 2
SP - 914
EP - 927
PB - Royal Society of Chemistry
CY - Cambridge
ER -
TY - JOUR
A1 - Schürmann, Robin
A1 - Titov, Evgenii
A1 - Ebel, Kenny
A1 - Kogikoski Junior, Sergio
A1 - Mostafa, Amr
A1 - Saalfrank, Peter
A1 - Milosavljević, Aleksandar R.
A1 - Bald, Ilko
T1 - The electronic structure of the metal-organic interface of isolated ligand coated gold nanoparticles
JF - Nanoscale Advances
N2 - Light induced electron transfer reactions of molecules on the surface of noble metal nanoparticles (NPs) depend significantly on the electronic properties of the metal-organic interface. Hybridized metal-molecule states and dipoles at the interface alter the work function and facilitate or hinder electron transfer between the NPs and ligand. X-ray photoelectron spectroscopy (XPS) measurements of isolated AuNPs coated with thiolated ligands in a vacuum have been performed as a function of photon energy, and the depth dependent information of the metal-organic interface has been obtained. The role of surface dipoles in the XPS measurements of isolated ligand coated NPs is discussed and the binding energy of the Au 4f states is shifted by around 0.8 eV in the outer atomic layers of 4-nitrothiophenol coated AuNPs, facilitating electron transport towards the molecules. Moreover, the influence of the interface dipole depends significantly on the adsorbed ligand molecules. The present study paves the way towards the engineering of the electronic properties of the nanoparticle surface, which is of utmost importance for the application of plasmonic nanoparticles in the fields of heterogeneous catalysis and solar energy conversion.
Y1 - 2022
U6 - https://doi.org/10.1039/d1na00737h
SN - 2516-0230
VL - 4
IS - 6
SP - 1599
EP - 1607
PB - Royal Society of Chemistry
CY - Cambridge
ER -
TY - JOUR
A1 - Li, Zhen
A1 - Spangenberg, Erik
A1 - Schicks, Judith Maria
A1 - Kempka, Thomas
T1 - Numerical simulation of hydrate formation in the LArge-Scale Reservoir Simulator (LARS)
JF - Energies : open-access journal of related scientific research, technology development and studies in policy and management
N2 - The LArge-scale Reservoir Simulator (LARS) has been previously developed to study hydrate dissociation in hydrate-bearing systems under in-situ conditions. In the present study, a numerical framework of equations of state describing hydrate formation at equilibrium conditions has been elaborated and integrated with a numerical flow and transport simulator to investigate a multi-stage hydrate formation experiment undertaken in LARS. A verification of the implemented modeling framework has been carried out by benchmarking it against another established numerical code. Three-dimensional (3D) model calibration has been performed based on laboratory data available from temperature sensors, fluid sampling, and electrical resistivity tomography. The simulation results demonstrate that temperature profiles, spatial hydrate distribution, and bulk hydrate saturation are consistent with the observations. Furthermore, our numerical framework can be applied to calibrate geophysical measurements, optimize post-processing workflows for monitoring data, improve the design of hydrate formation experiments, and investigate the temporal evolution of sub-permafrost methane hydrate reservoirs.
KW - methane hydrate
KW - temperature sensor
KW - electrical resistivity tomography
KW - hydrate formation
KW - numerical simulation
Y1 - 2022
U6 - https://doi.org/10.3390/en15061974
SN - 1996-1073
VL - 15
IS - 6
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Goswami, Koushik
T1 - Inertial particle under active fluctuations
BT - diffusion and work distributions
JF - Physical review E, Statistical, nonlinear, and soft matter physics
N2 - We study the underdamped motion of a passive particle in an active environment. Using the phase space path integral method we find the probability distribution function of position and velocity for a free and a harmonically bound particle. The environment is characterized by an active noise which is described as the Ornstein-Uhlenbeck process (OUP). Taking two similar, yet slightly different OUP models, it is shown how inertia along with other relevant parameters affect the dynamics of the particle. Further we investigate the work fluctuations of a harmonically trapped particle by considering the trap center being pulled at a constant speed. Finally, the fluctuation theorem of work is validated with an effective temperature in the steady-state limit.
Y1 - 2022
U6 - https://doi.org/10.1103/PhysRevE.105.044123
SN - 2470-0045
SN - 2470-0053
VL - 105
IS - 4
PB - American Physical Society
CY - College Park
ER -
TY - JOUR
A1 - Xie, Dongjiu
A1 - Jouini, Oumeima
A1 - Mei, Shilin
A1 - Quan, Ting
A1 - Xu, Yaolin
A1 - Kochovski, Zdravko
A1 - Lu, Yan
T1 - Spherical polyelectrolyte brushes templated hollow C@MnO nanospheres as sulfur host materials for Li-S batteries
JF - ChemNanoMat : Chemistry of Nanomaterials for Energy, Biology and More
N2 - Li-S battery has been considered as the next-generation energy storage device, which still suffers from the shuttle effect of lithium polysulfides (LiPSs). In this work, mesoporous hollow carbon-coated MnO nanospheres (C@MnO) have been designed and synthesized using spherical polyelectrolyte brushes (SPB) as template, KMnO4 as MnO precursor, and polydopamine as carbon source to improve the electrochemical performance of Li-S battery. The hollow C@MnO nanospheres enable the combination of physical confinement and chemical adsorption of the LiPSs. The thin carbon coating layer can provide good electrical conductivity and additional physical confinement to polysulfides. Moreover, the encapsulated MnO inside the carbon shell exhibits strong chemical adsorption to polysulfides. The constructed C@MnO/S cathode shows the discharge capacity of 1026 mAh g(-1) at 0.1 C with 79% capacity retention after 80 cycles. The synthesized hollow C@MnO nanoparticles can work as highly efficient sulfur host materials, providing an effective solution to suppress the shuttle effect in Li-S battery.
KW - hollow nanospheres
KW - lithium-sulfur battery
KW - manganese monoxide
KW - sperical
KW - polyelectrolyte brushes
Y1 - 2022
U6 - https://doi.org/10.1002/cnma.202100455
SN - 2199-692X
VL - 8
IS - 4
PB - Wiley-VCH
CY - Weinheim
ER -
TY - JOUR
A1 - Fischer, Eric Wolfgang
A1 - Werther, Michael
A1 - Bouakline, Foudhil
A1 - Grossmann, Frank
A1 - Saalfrank, Peter
T1 - Non-Markovian vibrational relaxation dynamics at surfaces
JF - The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr
N2 - Vibrational dynamics of adsorbates near surfaces plays both an important role for applied surface science and as a model lab for studying fundamental problems of open quantum systems. We employ a previously developed model for the relaxation of a D-Si-Si bending mode at a D:Si(100)-(2 x 1) surface, induced by a "bath " of more than 2000 phonon modes [Lorenz and P. Saalfrank, Chem. Phys. 482, 69 (2017)], to extend previous work along various directions. First, we use a Hierarchical Effective Mode (HEM) model [Fischer et al., J. Chem. Phys. 153, 064704 (2020)] to study relaxation of higher excited vibrational states than hitherto done by solving a high-dimensional system-bath time-dependent Schrodinger equation (TDSE). In the HEM approach, (many) real bath modes are replaced by (much less) effective bath modes. Accordingly, we are able to examine scaling laws for vibrational relaxation lifetimes for a realistic surface science problem. Second, we compare the performance of the multilayer multiconfigurational time-dependent Hartree (ML-MCTDH) approach with that of the recently developed coherent-state-based multi-Davydov-D2 Ansatz [Zhou et al., J. Chem. Phys. 143, 014113 (2015)]. Both approaches work well, with some computational advantages for the latter in the presented context. Third, we apply open-system density matrix theory in comparison with basically "exact " solutions of the multi-mode TDSEs. Specifically, we use an open-system Liouville-von Neumann (LvN) equation treating vibration-phonon coupling as Markovian dissipation in Lindblad form to quantify effects beyond the Born-Markov approximation. Published under an exclusive license by AIP Publishing.
KW - phonons
KW - Vibrational states
KW - Chemical dynamics
KW - Adsorption
KW - Surface science
KW - Open quantum systems
KW - Density-matrix
KW - Coherent states
KW - Markov processes
Y1 - 2022
U6 - https://doi.org/10.1063/5.0092836
SN - 0021-9606
SN - 1089-7690
SN - 1520-9032
VL - 156
IS - 21
PB - AIP Publishing
CY - Melville
ER -
TY - JOUR
A1 - Chea, Sany
A1 - Nguyen, Khac Toan
A1 - Rosencrantz, Ruben R.
T1 - Microwave-Assisted Synthesis of 5 '-O-methacryloylcytidine Using the Immobilized Lipase Novozym 435
JF - Molecules
N2 - Nucleobase building blocks have been demonstrated to be strong candidates when it comes to DNA/RNA-like materials by benefiting from hydrogen bond interactions as physical properties. Modifying at the 5 ' position is the simplest way to develop nucleobase-based structures by transesterification using the lipase Novozym 435. Herein, we describe the optimization of the lipase-catalyzed synthesis of the monomer 5 '-O-methacryloylcytidine with the assistance of microwave irradiation. Variable reaction parameters, such as enzyme concentration, molar ratio of the substrate, reaction temperature and reaction time, were investigated to find the optimum reaction condition in terms of obtaining the highest yield.
KW - microwave irradiation
KW - Novozym 435
KW - cytidine
KW - monomer
KW - smart materials
Y1 - 2022
U6 - https://doi.org/10.3390/molecules27134112
SN - 1420-3049
VL - 27
IS - 13
PB - MDPI
CY - Basel
ER -
TY - JOUR
A1 - Balischewski, Christian
A1 - Bhattacharyya, Biswajit
A1 - Sperlich, Eric
A1 - Günter, Christina
A1 - Beqiraj, Alkit
A1 - Klamroth, Tillmann
A1 - Behrens, Karsten
A1 - Mies, Stefan
A1 - Kelling, Alexandra
A1 - Lubahn, Susanne
A1 - Holtzheimer, Lea
A1 - Nitschke, Anne
A1 - Taubert, Andreas
T1 - Tetrahalidometallate(II) ionic liquids with more than one metal
BT - the effect of bromide versus chloride
JF - Chemistry - a European journal
N2 - Fifteen N-butylpyridinium salts - five monometallic [C4Py](2)[MBr4] and ten bimetallic [C4Py](2)[(M0.5M0.5Br4)-M-a-Br-b] (M=Co, Cu, Mn, Ni, Zn) - were synthesized, and their structures and thermal and electrochemical properties were studied. All the compounds are ionic liquids (ILs) with melting points between 64 and 101 degrees C. Powder and single-crystal X-ray diffraction show that all ILs are isostructural. The electrochemical stability windows of the ILs are between 2 and 3 V. The conductivities at room temperature are between 10(-5) and 10(-6) S cm(-1). At elevated temperatures, the conductivities reach up to 10(-4) S cm(-1) at 70 degrees C. The structures and properties of the current bromide-based ILs were also compared with those of previous examples using chloride ligands, which illustrated differences and similarities between the two groups of ILs.
KW - electrochemistry
KW - ionic liquids
KW - metal-containing ionic liquids;
KW - N-butylpyridinium bromide
KW - tetrahalidometallates
Y1 - 2022
U6 - https://doi.org/10.1002/chem.202201068
SN - 1521-3765
VL - 28
IS - 64
PB - Wiley-VCH
CY - Weinheim
ER -
TY - JOUR
A1 - Sandmann, Michael
A1 - Münzberg, Marvin
A1 - Bressel, Lena
A1 - Reich, Oliver
A1 - Hass, Roland
T1 - Inline monitoring of high cell density cultivation of Scenedesmus rubescens in a mesh ultra-thin layer photobioreactor by photon density wave spectroscopy
JF - BMC Research Notes / Biomed Central
N2 - Objective Due to multiple light scattering that occurs inside and between cells, quantitative optical spectroscopy in turbid biological suspensions is still a major challenge. This includes also optical inline determination of biomass in bioprocessing. Photon Density Wave (PDW) spectroscopy, a technique based on multiple light scattering, enables the independent and absolute determination of optical key parameters of concentrated cell suspensions, which allow to determine biomass during cultivation. Results A unique reactor type, called "mesh ultra-thin layer photobioreactor" was used to create a highly concentrated algal suspension. PDW spectroscopy measurements were carried out continuously in the reactor without any need of sampling or sample preparation, over 3 weeks, and with 10-min time resolution. Conventional dry matter content and coulter counter measurements have been employed as established offline reference analysis. The PBR allowed peak cell dry weight (CDW) of 33.4 g L-1. It is shown that the reduced scattering coefficient determined by PDW spectroscopy is strongly correlated with the biomass concentration in suspension and is thus suitable for process understanding. The reactor in combination with the fiber-optical measurement approach will lead to a better process management.
KW - Photon density wave spectroscopy
KW - Multiple light scattering
KW - Process
KW - analytical technology
KW - Fiber-optical spectroscopy
KW - Mesh ultra-thin layer
KW - photobioreactor
Y1 - 2022
U6 - https://doi.org/10.1186/s13104-022-05943-2
SN - 1756-0500
VL - 15
IS - 1
PB - Biomed Central (London)
CY - London
ER -
TY - JOUR
A1 - Schürmann, Robin
A1 - Nagel, Alessandro
A1 - Juergensen, Sabrina
A1 - Pathak, Anisha
A1 - Reich, Stephanie
A1 - Pacholski, Claudia
A1 - Bald, Ilko
T1 - Microscopic understanding of reaction rates observed in plasmon chemistry of nanoparticle-ligand systems
JF - The journal of physical chemistry : C, Nanomaterials and interfaces
N2 - Surface-enhanced Raman scattering (SERS) is an effective and widely used technique to study chemical reactions induced or catalyzed by plasmonic substrates, since the experimental setup allows us to trigger and track the reaction simultaneously and identify the products. However, on substrates with plasmonic hotspots, the total signal mainly originates from these nanoscopic volumes with high reactivity and the information about the overall consumption remains obscure in SERS measurements. This has important implications; for example, the apparent reaction order in SERS measurements does not correlate with the real reaction order, whereas the apparent reaction rates are proportional to the real reaction rates as demonstrated by finite-difference time-domain (FDTD) simulations. We determined the electric field enhancement distribution of a gold nanoparticle (AuNP) monolayer and calculated the SERS intensities in light-driven reactions in an adsorbed self-assembled molecular monolayer on the AuNP surface. Accordingly, even if a high conversion is observed in SERS due to the high reactivity in the hotspots, most of the adsorbed molecules on the AuNP surface remain unreacted. The theoretical findings are compared with the hot-electron-induced dehalogenation of 4-bromothiophenol, indicating a time dependency of the hot-carrier concentration in plasmon-mediated reactions. To fit the kinetics of plasmon-mediated reactions in plasmonic hotspots, fractal-like kinetics are well suited to account for the inhomogeneity of reactive sites on the substrates, whereas also modified standard kinetics model allows equally well fits. The outcomes of this study are on the one hand essential to derive a mechanistic understanding of reactions on plasmonic substrates by SERS measurements and on the other hand to drive plasmonic reactions with high local precision and facilitate the engineering of chemistry on a nanoscale.
Y1 - 2022
U6 - https://doi.org/10.1021/acs.jpcc.2c00278
SN - 1932-7447
SN - 1932-7455
VL - 126
IS - 11
SP - 5333
EP - 5342
PB - American Chemical Society
CY - Washington
ER -
TY - JOUR
A1 - Chea, Sany
A1 - Schade, Kristin
A1 - Reinicke, Stefan
A1 - Bleul, Regina
A1 - Rosencrantz, Ruben R.
T1 - Synthesis and self-assembly of cytidine- and guanosine-based copolymers
JF - Polymer Chemistry
N2 - The base pairing property and the "melting" behavior of oligonucleotides can take advantage to develop new smart thermoresponsive and programmable materials. Complementary cytidine- (C) and guanosine- (G) based monomers were blockcopolymerized using RAFT polymerization technique with poly-(N-(2-hydroxypropyl) methacrylamide) (pHPMA) as the hydrophilic macro chain transfer agent (macro-CTA). C-C, G-G and C-G hydrogen bond interactions of blockcopolymers with respectively C and G moieties have been investigated using SEM, DLS and UV-Vis. Mixing and heating both complementary copolymers resulted in reforming new aggregates. Due to the ribose moiety of the isolated nucleoside-bearing blockcopolymers, the polarity is increased for better solubility. Self-assembly investigations of these bioinspired compounds are the crucial basis for the development of potential future drug delivery systems.
Y1 - 2022
U6 - https://doi.org/10.1039/d2py00615d
SN - 1759-9954
SN - 1759-9962
VL - 13
IS - 35
SP - 5058
EP - 5067
PB - Royal Society of Chemistry
CY - Cambridge
ER -
TY - JOUR
A1 - Sperlich, Eric
A1 - Köckerling, Martin
T1 - [Nb6Cl14(pyrazine)(4)], a versatile precursor for ligand-supported hexanuclear niobium cluster compounds: synthesis, characterization, follow-up reactions, and intermolecular interactions
JF - Inorganic chemistry
N2 - The compound [Nb6Cl14(pyrazine)(4)]center dot 2CH(2)Cl(2) (1) was investigated for its suitability as a starting compound for new ligand-supported hexanuclear niobium cluster compounds. The synthesis, stability to air and increased temperature, solubility and usability for subsequent reactions of 1, and purification and separation of the reaction products are discussed. The compounds with cluster units [Nb6Cl14L4], where L = iso-quinoline N-oxides (2), 1,1-dimethylethylenediamines (3), or thiazoles (4), and [Nb6Cl14(PEt3)(3.76)(Et3PO)(0.24)]-[Nb6Cl14(MeCN)(4)]center dot 4MeCN (5) are presented as follow-up products. The crystal structures of compounds 1-5 are analyzed, and the structures are discussed with respect to their intraand intermolecular bonding situations and crystal packing. In addition to hydrogen bonds and pi-pi interactions, the appearance of chalcogen and halogen bonds and lone pair-pi interactions between Nb-6 cluster units was observed for the first time.
KW - Cluster chemistry
KW - crystals
KW - ligands
KW - molecules
KW - transition metals
Y1 - 2022
U6 - https://doi.org/10.1021/acs.inorgchem.1c03109
SN - 0020-1669
SN - 1520-510X
VL - 61
IS - 5
SP - 2409
EP - 2420
PB - American Chemical Society
CY - Washington
ER -