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  - Breternitz, Joachim
A1  - Schorr, Susan
T1  - Symmetry relations in wurtzite nitrides and oxide nitrides and the curious case of Pmc2(1)
JF  - Acta crystallographica / International Union of Crystallography. Section A, Foundations and advances
N2  - Binary III-V nitrides such as AlN, GaN and InN in the wurtzite-type structure have long been considered as potent semiconducting materials because of their optoelectronic properties, amongst others. With rising concerns over the utilization of scarce elements, a replacement of the trivalent cations by others in ternary and multinary nitrides has led to the development of different variants of nitrides and oxide nitrides crystallizing in lower-symmetry variants of wurtzite. This work presents the symmetry relationships between these structural types specific to nitrides and oxide nitrides and updates some prior work on this matter. The non-existence of compounds crystallizing in Pmc2(1), formally the highest subgroup of the wurtzite type fulfilling Pauling's rules for 1:1:2 stoichiometries, has been puzzling scientists for a while; a rationalization is given, from a crystallographic basis, of why this space group is unlikely to be adopted.
KW  - group-subgroup relationships
KW  - nitride materials
KW  - wurtzite type
Y1  - 2021
U6  - https://doi.org/10.1107/S2053273320015971
SN  - 2053-2733
VL  - 77
IS  - 3
SP  - 208
EP  - 216
PB  - Blackwell
CY  - Oxford [u.a.]
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  - Haubitz, Toni
A1  - Drobot, Björn
A1  - Tsushima, Satoru
A1  - Steudtner, Robin
A1  - Stumpf, Thorsten
A1  - Kumke, Michael Uwe
T1  - Quenching mechanism of uranyl(VI) by chloride and bromide in aqueous and non-aqueous solutions
JF  - The journal of physical chemistry : A, Molecules, spectroscopy, kinetics, environment & general theory
N2  - A major hindrance in utilizing uranyl(VI) luminescence as a standard analytical tool, for example, in environmental monitoring or nuclear industries, is quenching by other ions such as halide ions, which are present in many relevant matrices of uranyl(VI) speciation. Here, we demonstrate through a combination of time-resolved laser-induced fluorescence spectroscopy, transient absorption spectroscopy, and quantum chemistry that coordinating solvent molecules play a crucial role in U(VI) halide luminescence quenching. We show that our previously suggested quenching mechanism based on an internal redox reaction of the 1:2-uranyl-halide-complex holds also true for bromide-induced quenching of uranyl(VI). By adopting specific organic solvents, we were able to suppress the separation of the oxidized halide ligand X-2(center dot-) and the formed uranyl(V) into fully solvated ions, thereby "reigniting" U(VI) luminescence. Time-dependent density functional theory calculations show that quenching occurs through the outer-sphere complex of U(VI) and halide in water, while the ligand-to-metal charge transfer is strongly reduced in acetonitrile.
Y1  - 2021
U6  - https://doi.org/10.1021/acs.jpca.1c02487
SN  - 1089-5639
SN  - 1520-5215
VL  - 125
IS  - 20
SP  - 4380
EP  - 4389
PB  - American Chemical Society
CY  - Washington
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  - Reitenbach, Julija
A1  - Geiger, Christina
A1  - Wang, Peixi
A1  - Vagias, Apostolos N.
A1  - Cubitt, Robert
A1  - Schanzenbach, Dirk
A1  - Laschewsky, André
A1  - Papadakis, Christine M.
A1  - Müller-Buschbaum, Peter
T1  - Effect of magnesium salts with chaotropic anions on the swelling behavior of PNIPMAM thin films
JF  - Macromolecules : a publication of the American Chemical Society
N2  - Poly(N-isopropylmethacrylamide) (PNIPMAM) is a stimuli responsive polymer, which in thin film geometry exhibits a volume-phase transition upon temperature increase in water vapor. The swelling behavior of PNIPMAM thin films containing magnesium salts in water vapor is investigated in view of their potential application as nanodevices. Both the extent and the kinetics of the swelling ratio as well as the water content are probed with in situ time-of-flight neutron reflectometry. Additionally, in situ Fourier-transform infrared (FTIR) spectroscopy provides information about the local solvation of the specific functional groups, while two-dimensional FTIR correlation analysis further elucidates the temporal sequence of solvation events. The addition of Mg(ClO4)2 or Mg(NO3)2 enhances the sensitivity of the polymer and therefore the responsiveness of switches and sensors based on PNIPMAM thin films. It is found that Mg(NO3)2 leads to a higher relative water uptake and therefore achieves the highest thickness gain in the swollen state.
Y1  - 2023
U6  - https://doi.org/10.1021/acs.macromol.2c02282
SN  - 0024-9297
SN  - 1520-5835
VL  - 56
IS  - 2
SP  - 567
EP  - 577
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - CHAP
A1  - Breternitz, Joachim
A1  - Schorr, Susan
T1  - Halide perovskites
BT  - structural systematisation and what we learn from it
T2  - Acta crystallographica / International Union of Crystallography. Section A, Foundations and advances
KW  - halide perovskites
KW  - semiconductors
KW  - group-subgroup relations
KW  - twinning
Y1  - 2021
SN  - 2053-2733
SN  - 1600-5724
SN  - 1600-8596
SN  - 0108-7673
SN  - 0567-7394
VL  - 77
IS  - Suppl.
SP  - C750
EP  - C750
PB  - Blackwell
CY  - Oxford [u.a.]
ER  - 
TY  - JOUR
A1  - Nchiozem-Ngnitedem, Vaderament-Alexe
A1  - Sperlich, Eric
A1  - Matieta, Valaire Yemene
A1  - Kuete, Jenifer Reine Ngnouzouba
A1  - Kuete, Victor
A1  - Omer, Ejlal A. A.
A1  - Efferth, Thomas
A1  - Schmidt, Bernd
T1  - Synthesis and bioactivity of isoflavones from ficus carica and some non-natural analogues
JF  - Journal of natural products : Lloydia
N2  - FicucariconeD (1) and its 4 '-demethyl congener 2 are isoflavones isolated from fruits of Ficus carica that share a 5,7-dimethoxy-6-prenyl-substituted A-ring. Both naturalproducts were, for the first time, obtained by chemical synthesisin six steps, starting from 2,4,6-trihydroxyacetophenone. Key stepsare a microwave-promoted tandem sequence of Claisen- and Cope-rearrangementsto install the 6-prenyl substituent and a Suzuki-Miyaura crosscoupling for installing the B-ring. By using various boronic acids,non-natural analogues become conveniently available. All compoundswere tested for cytotoxicity against drug-sensitive and drug-resistanthuman leukemia cell lines, but were found to be inactive. The compoundswere also tested for antimicrobial activities against a panel of eightGram-negative and two Gram-positive bacterial strains. Addition ofthe efflux pump inhibitor phenylalanine-arginine-beta-naphthylamide(PA beta N) significantly improved the antibiotic activity in mostcases, with MIC values as low as 2.5 mu M and activity improvementfactors as high as 128-fold.
KW  - Antimicrobial activity
KW  - Bacteria
KW  - Ethers
KW  - Flavonoids
KW  - Mixtures
Y1  - 2023
U6  - https://doi.org/10.1021/acs.jnatprod.3c00219
SN  - 0163-3864
SN  - 1520-6025
VL  - 86
IS  - 6
SP  - 1520
EP  - 1528
PB  - American Chemical Society
CY  - Washington, DC
ER  - 
TY  - JOUR
A1  - Geiger, Christina
A1  - Reitenbach, Julija
A1  - Henschel, Cristiane
A1  - Kreuzer, Lucas
A1  - Widmann, Tobias
A1  - Wang, Peixi
A1  - Mangiapia, Gaetano
A1  - Moulin, Jean-François
A1  - Papadakis, Christine M.
A1  - Laschewsky, André
A1  - Müller-Buschbaum, Peter
T1  - Ternary nanoswitches realized with multiresponsive PMMA-b-PNIPMAM films in mixed water/acetone vapor atmospheres
JF  - Advanced engineering materials
N2  - To systematically add functionality to nanoscale polymer switches, an understanding of their responsive behavior is crucial. Herein, solvent vapor stimuli are applied to thin films of a diblock copolymer consisting of a short poly(methyl methacrylate) (PMMA) block and a long poly(N-isopropylmethacrylamide) (PNIPMAM) block for realizing ternary nanoswitches. Three significantly distinct film states are successfully implemented by the combination of amphiphilicity and co-nonsolvency effect. The exposure of the thin films to nitrogen, pure water vapor, and mixed water/acetone (90 vol%/10 vol%) vapor switches the films from a dried to a hydrated (solvated and swollen) and a water/acetone-exchanged (solvated and contracted) equilibrium state. These three states have distinctly different film thicknesses and solvent contents, which act as switch positions "off," "on," and "standby." For understanding the switching process, time-of-flight neutron reflectometry (ToF-NR) and spectral reflectance (SR) studies of the swelling and dehydration process are complemented by information on the local solvation of functional groups probed with Fourier-transform infrared (FTIR) spectroscopy. An accelerated responsive behavior beyond a minimum hydration/solvation level is attributed to the fast build-up and depletion of the hydration shell of PNIPMAM, caused by its hydrophobic moieties promoting a cooperative hydration character.
KW  - co-nonsolvency
KW  - diblock copolymers
KW  - nanoswitches
KW  - neutron reflectometry
KW  - thin films
Y1  - 2021
U6  - https://doi.org/10.1002/adem.202100191
SN  - 1438-1656
SN  - 1527-2648
VL  - 23
IS  - 11
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Melani, Giacomo
A1  - Nagata, Yuki
A1  - Saalfrank, Peter
T1  - Vibrational energy relaxation of interfacial OH on a water-covered alpha-Al2O3(0001) surface
BT  - a non-equilibrium ab initio molecular dynamics study
JF  - Physical chemistry, chemical physics : PCCP ; a journal of European chemical societies
N2  - Vibrational relaxation of adsorbates is a sensitive tool to probe energy transfer at gas/solid and liquid/solid interfaces. The most direct way to study relaxation dynamics uses time-resolved spectroscopy. Here we report on a non-equilibrium ab initio molecular dynamics (NE-AIMD) methodology to model vibrational relaxation of OH vibrations on a hydroxylated, water-covered alpha-Al2O3(0001) surface. In our NE-AIMD approach, after exciting selected O-H bonds their coupling to surface phonons and to the water adlayer is analyzed in detail, by following both the energy flow in time, as well as the time-evolution of Vibrational Density of States (VDOS) curves. The latter are obtained from Time-dependent Correlation Functions (TCFs) and serve as prototypical, generic representatives of time-resolved vibrational spectra. As most important results, (i) we find a few-picosecond lifetime of the excited modes and (ii) identify both hydrogen-bonded aluminols and water molecules in the adsorbed water layer as main dissipative channels, while the direct coupling to Al2O3 surface phonons is of minor importance on the timescales of interest. Our NE-AIMD/TCF methodology is powerful for complex adsorbate systems, in principle even reacting ones, and opens a way towards time-resolved vibrational spectroscopy.
Y1  - 2021
U6  - https://doi.org/10.1039/d0cp03777j
SN  - 1463-9076
SN  - 1463-9084
VL  - 23
IS  - 13
SP  - 7714
EP  - 7723
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Wang, Zhenyu
A1  - Fritsch, Daniel
A1  - Berendts, Stefan
A1  - Lerch, Martin
A1  - Breternitz, Joachim
A1  - Schorr, Susan
T1  - Elucidation of the reaction mechanism for the synthesis of ZnGeN2 through Zn2GeO4 ammonolysis
JF  - Chemical science / RSC, Royal Society of Chemistry
N2  - Ternary II-IV-N-2 materials have been considered as a promising class of materials that combine photovoltaic performance with earth-abundance and low toxicity. When switching from binary III-V materials to ternary II-IV-N-2 materials, further structural complexity is added to the system that may influence its optoelectronic properties. Herein, we present a systematic study of the reaction of Zn2GeO4 with NH3 that produces zinc germanium oxide nitrides, and ultimately approach stoichiometric ZnGeN2, using a combination of chemical analyses, X-ray powder diffraction and DFT calculations. Elucidating the reaction mechanism as being dominated by Zn and O extrusion at the later reaction stages, we give an insight into studying structure-property relationships in this emerging class of materials.
Y1  - 2021
U6  - https://doi.org/10.1039/d1sc00328c
SN  - 2041-6539
VL  - 12
IS  - 24
SP  - 8493
EP  - 8500
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Saeedi Garakani, Sadaf
A1  - Xie, Dongjiu
A1  - Khorsand Kheirabad, Atefeh
A1  - Lu, Yan
A1  - Yuan, Jiayin
T1  - Template-synthesis of a poly(ionic liquid)-derived Fe1-xS/nitrogen-doped porous carbon membrane and its electrode application in lithium-sulfur batteries
JF  - Materials advances
N2  - This study deals with the facile synthesis of Fe1-xS nanoparticle-containing nitrogen-doped porous carbon membranes (denoted as Fe1-xS/N-PCMs) via vacuum carbonization of hybrid porous poly(ionic liquid) (PIL) membranes, and their successful use as a sulfur host material to mitigate the shuttle effect in lithium-sulfur (Li-S) batteries. The hybrid porous PIL membranes as the sacrificial template were prepared via ionic crosslinking of a cationic PIL with base-neutralized 1,1 '-ferrocenedicarboxylic acid, so that the iron source was molecularly incorporated into the template. The carbonization process was investigated in detail at different temperatures, and the chemical and porous structures of the carbon products were comprehensively analyzed. The Fe1-xS/N-PCMs prepared at 900 degrees C have a multimodal pore size distribution with a satisfactorily high surface area and well-dispersed iron sulfide nanoparticles to physically and chemically confine the LiPSs. The sulfur/Fe1-xS/N-PCM composites were then tested as electrodes in Li-S batteries, showing much improved capacity, rate performance and cycle stability, in comparison to iron sulfide-free, nitrogen-doped porous carbon membranes.
Y1  - 2021
U6  - https://doi.org/10.1039/d1ma00441g
SN  - 2633-5409
VL  - 2
IS  - 15
SP  - 5203
EP  - 5212
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Xu, Xun
A1  - Nie, Yan
A1  - Wang, Weiwei
A1  - Ma, Nan
A1  - Lendlein, Andreas
T1  - Periodic thermomechanical modulation of toll-like receptor expression and distribution in mesenchymal stromal cells
JF  - MRS communications / a publication of the Materials Research Society
N2  - Toll-like receptor (TLR) can trigger an immune response against virus including SARS-CoV-2. TLR expression/distribution is varying in mesenchymal stromal cells (MSCs) depending on their culture environments. Here, to explore the effect of periodic thermomechanical cues on TLRs, thermally controlled shape-memory polymer sheets with programmable actuation capacity were created. The proportion of MSCs expressing SARS-CoV-2-associated TLRs was increased upon stimulation. The TLR4/7 colocalization was promoted and retained in the endoplasmic reticula. The TLR redistribution was driven by myosin-mediated F-actin assembly. These results highlight the potential of boosting the immunity for combating COVID-19 via thermomechanical preconditioning of MSCs.
KW  - Actuation
KW  - Antiviral
KW  - Biomaterial
KW  - COVID-19
KW  - Shape memory
Y1  - 2021
U6  - https://doi.org/10.1557/s43579-021-00049-5
SN  - 2159-6859
SN  - 2159-6867
VL  - 11
IS  - 4
SP  - 425
EP  - 431
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Schulze, Nicole
A1  - Koetz, Joachim
T1  - Kinetically controlled growth of gold nanotriangles in a vesicular template phase by adding a strongly alternating polyampholyte
JF  - Journal of dispersion science and technology
N2  - This paper is focused on the temperature-dependent synthesis of gold nanotriangles in a vesicular template phase, containing phosphatidylcholine and AOT, by adding the strongly alternating polyampholyte PalPhBisCarb.
UV-vis absorption spectra in combination with TEM micrographs show that flat gold nanoplatelets are formed predominantly in the presence of the polyampholyte at 45°C. The formation of triangular and hexagonal nanoplatelets can be directly influenced by the kinetic approach, i.e., by varying the polyampholyte dosage rate at 45°C. Corresponding zeta potential measurements indicate that a temperature-dependent adsorption of the polyampholyte on the {111} faces will induce the symmetry breaking effect, which is responsible for the kinetically controlled hindered vertical and preferred lateral growth of the nanoplatelets.
KW  - Kinetically controlled nanocrystal growth
KW  - nanotriangles
KW  - polyampholytes
Y1  - 2016
U6  - https://doi.org/10.1080/01932691.2016.1220318
SN  - 0193-2691
SN  - 1532-2351
VL  - 38
IS  - 8
SP  - 1073
EP  - 1078
PB  - Taylor & Francis
CY  - Philadelphia
ER  - 
TY  - THES
A1  - Margraf, Johannes T.
T1  - Science-driven chemical machine learning
Y1  - 2023
ER  - 
TY  - JOUR
A1  - Deng, Zijun
A1  - Wang, Weiwei
A1  - Xu, Xun
A1  - Ma, Nan
A1  - Lendlein, Andreas
T1  - Polydopamine-based biofunctional substrate coating promotes mesenchymal stem cell migration
JF  - MRS advances : a journal of the Materials Research Society (MRS)
N2  - Rapid migration of mesenchymal stem cells (MSCs) on device surfaces could support in vivo tissue integration and might facilitate in vitro organoid formation. Here, polydopamine (PDA) is explored as a biofunctional coating to effectively promote MSC motility. It is hypothesized that PDA stimulates fibronectin deposition and in this way enhances integrin-mediated migration capability. The random and directional cell migration was investigated by time-lapse microscopy and gap closure assay respectively, and analysed with softwares as computational tools. A higher amount of deposited fibronectin was observed on PDA substrate, compared to the non-coated substrate. The integrin beta 1 activation and focal adhesion kinase (FAK) phosphorylation at Y397 were enhanced on PDA substrate, but the F-actin cytoskeleton was not altered, suggesting MSC migration on PDA was regulated by integrin initiated FAK signalling. This study strengthens the biofunctionality of PDA coating for regulating stem cells and offering a way of facilitating tissue integration of devices.
Y1  - 2021
U6  - https://doi.org/10.1557/s43580-021-00091-4
SN  - 2059-8521
VL  - 6
IS  - 31
SP  - 739
EP  - 744
PB  - Springer Nature Switzerland AG
CY  - Cham
ER  - 
TY  - JOUR
A1  - Machatschek, Rainhard Gabriel
A1  - Saretia, Shivam
A1  - Lendlein, Andreas
T1  - Assessing the influence of temperature-memory creation on the degradation of copolyesterurethanes in ultrathin films
JF  - Advanced materials interfaces
N2  - Copolyesterurethanes (PDLCLs) based on oligo(epsilon-caprolactone) (OCL) and oligo(omega-pentadecalactone) (OPDL) segments are biodegradable thermoplastic temperature-memory polymers. The temperature-memory capability in these polymers with crystallizable control units is implemented by a thermomechanical programming process causing alterations in the crystallite arrangement and chain organization. These morphological changes can potentially affect degradation. Initial observations on the macroscopic level inspire the hypothesis that switching of the controlling units causes an accelerated degradation of the material, resulting in programmable degradation by sequential coupling of functions. Hence, detailed degradation studies on Langmuir films of a PDLCL with 40 wt% OPDL content are carried out under enzymatic catalysis. The temperature-memory creation procedure is mimicked by compression at different temperatures. The evolution of the chain organization and mechanical properties during the degradation process is investigated by means of polarization-modulated infrared reflection absorption spectroscopy, interfacial rheology and to some extend by X-ray reflectivity. The experiments on PDLCL Langmuir films imply that degradability is not enhanced by thermal switching, as the former depends on the temperature during cold programming. Nevertheless, the thin film experiments show that the leaching of OCL segments does not induce further crystallization of the OPDL segments, which is beneficial for a controlled and predictable degradation.
KW  - block copolymers
KW  - degradation
KW  - Langmuir monolayers
KW  - rheology
KW  - temperature-memory polymers
Y1  - 2021
U6  - https://doi.org/10.1002/admi.202001926
SN  - 2196-7350
VL  - 8
IS  - 6
PB  - Wiley-VCH
CY  - Weinheim
ER  -