@article{HaubitzFudickarLinkeretal.2020,
  author    = {Haubitz, Toni and Fudickar, Werner and Linker, Torsten and Kumke, Michael Uwe},
  title     = {pH-sensitive fluorescence switching of pyridylanthracenes},
  series = {The journal of physical chemistry : A, Molecules, spectroscopy, kinetics, environment \& general theory},
  volume    = {124},
  journal   = {The journal of physical chemistry : A, Molecules, spectroscopy, kinetics, environment \& general theory},
  number    = {52},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {1089-5639},
  doi       = {10.1021/acs.jpca.0c09911},
  pages     = {11017 -- 11024},
  year      = {2020},
  abstract  = {9,10-substituted anthracenes are known for their useful optical properties like fluorescence, which makes them frequently used probes in sensing applications. In this article, we investigate the fundamental photophysical properties of three pyridyl-substituted variants. The nitrogen atoms in the pyridinium six-membered rings are located in the ortho-, meta-, and para-positions in relation to the anthracene core. Absorption, fluorescence, and transient absorption measurements were carried out and were complemented by theoretical calculations. We monitored the photophysics of the anthracene derivatives in chloroform and water investigating the protonated as well as their nonprotonated forms. We found that the optical properties of the nonprotonated forms are strongly determined by the anthracene chromophore, with only small differences to other 9,10-substituted anthracenes, for example diphenyl anthracene. In contrast, protonation leads to a strong decrease in fluorescence intensity and lifetime. Transient absorption measurements and theoretical calculations revealed the formation of a charge-transfer state in the protonated chromophores, where electron density is shifted from the anthracene moiety toward the protonated pyridyl substituents. While the para- and ortho-derivatives' charge transfer is still moderately fluorescent, the meta-derivative is affected much stronger and shows nearly no fluorescence. This nitrogen-atom-position-dependent sensitivity to hydronium activity makes a combination of these fluorophores very attractive for pH-sensing applications covering a broadened pH range.},
  language  = {en}
}
@article{SchildeKellingUmbreenetal.2016,
  author    = {Schilde, Uwe and Kelling, Alexandra and Umbreen, Sumaira and Linker, Torsten},
  title     = {Crystal structures of three bicyclic carbohydrate derivatives},
  series = {Acta crystallographica Section E ; Crystallographic communications},
  volume    = {72},
  journal   = {Acta crystallographica Section E ; Crystallographic communications},
  number    = {12},
  publisher = {IUCR},
  address   = {Chester},
  issn      = {2056-9890},
  doi       = {10.1107/S2056989016018727},
  pages     = {1839 -- 1844},
  year      = {2016},
  abstract  = {The title compounds, [(1R,3R,4R,5R,6S)-4,5-bis(acetyloxy)-7-oxo-2-oxabicyclo- [4.2.0]octan-3-yl]methyl acetate, C14H18O8, (I), [(1S,4R,5S,6R)-5-acetyloxy-7- hydroxyimino-2-oxobicyclo[4.2.0]octan-4-yl acetate, C11H15NO6, (II), and [(3aR,5R,6R,7R,7aS)-6,7-bis(acetyloxy)-2-oxooctahydropyrano[3,2-b]pyrrol-5- yl]methyl acetate, C14H19NO8, (III), are stable bicyclic carbohydrate derivatives. They can easily be synthesized in a few steps from commercially available glycals. As a result of the ring strain from the four-membered rings in (I) and (II), the conformations of the carbohydrates deviate strongly from the ideal chair form. Compound (II) occurs in the boat form. In the five-membered lactam (III), on the other hand, the carbohydrate adopts an almost ideal chair conformation. As a result of the distortion of the sugar rings, the configurations of the three bicyclic carbohydrate derivatives could not be determined from their NMR coupling constants. From our three crystal structure determinations, we were able to establish for the first time the absolute configurations of all new stereocenters of the carbohydrate rings.},
  language  = {en}
}
@article{PerovicQinOschatz2020,
  author    = {Perovic, Milena and Qin, Qing and Oschatz, Martin},
  title     = {From molecular precursors to nanoparticles},
  series = {Advanced functional materials},
  volume    = {30},
  journal   = {Advanced functional materials},
  number    = {41},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1616-301X},
  doi       = {10.1002/adfm.201908371},
  pages     = {21},
  year      = {2020},
  abstract  = {Nanoporous carbon materials (NCMs) provide the "function" of high specific surface area and thus have large interface area for interactions with surrounding species, which is of particular importance in applications related to adsorption processes. The strength and mechanism of adsorption depend on the pore architecture of the NCMs. In addition, chemical functionalization can be used to induce changes of electron density and/or electron density distribution in the pore walls, thus further modifying the interactions between carbons and guest species. Typical approaches for functionalization of nanoporous materials with regular atomic construction like porous silica, metal-organic frameworks, or zeolites, cannot be applied to NCMs due to their less defined local atomic construction and abundant defects. Therefore, synthetic strategies that offer a higher degree of control over the process of functionalization are needed. Synthetic approaches for covalent functionalization of NCMs, that is, for the incorporation of heteroatoms into the carbon backbone, are critically reviewed with a special focus on strategies following the concept "from molecules to materials." Approaches for coordinative functionalization with metallic species, and the functionalization by nanocomposite formation between pristine carbon materials and heteroatom-containing carbons, are introduced as well. Particular focus is given to the influences of these functionalizations in adsorption-related applications.},
  language  = {en}
}
@article{HollandMoritzGraupnerMoelleretal.2018,
  author    = {Holland-Moritz, Henry and Graupner, Julia and M{\"o}ller, Wolfhard and Pacholski, Claudia and Ronning, Carsten},
  title     = {Dynamics of nanoparticle morphology under low energy ion irradiation},
  series = {Nanotechnology},
  volume    = {29},
  journal   = {Nanotechnology},
  number    = {31},
  publisher = {IOP Publ. Ltd.},
  address   = {Bristol},
  issn      = {0957-4484},
  doi       = {10.1088/1361-6528/aac36c},
  pages     = {7},
  year      = {2018},
  abstract  = {If nanostructures are irradiated with energetic ions, the mechanism of sputtering becomes important when the ion range matches about the size of the nanoparticle. Gold nanoparticles with diameters of similar to 50 nm on top of silicon substrates with a native oxide layer were irradiated by gallium ions with energies ranging from 1 to 30 keV in a focused ion beam system. High resolution in situ scanning electron microscopy imaging permits detailed insights in the dynamics of the morphology change and sputter yield. Compared to bulk-like structures or thin films, a pronounced shaping and enhanced sputtering in the nanostructures occurs, which enables a specific shaping of these structures using ion beams. This effect depends on the ratio of nanoparticle size and ion energy. In the investigated energy regime, the sputter yield increases at increasing ion energy and shows a distinct dependence on the nanoparticle size. The experimental findings are directly compared to Monte Carlo simulations obtained from iradina and TRI3DYN, where the latter takes into account dynamic morphological and compositional changes of the target.},
  language  = {en}
}
@article{MorgnerBennemannCywińskietal.2017,
  author    = {Morgner, Frank and Bennemann, Mark and Cywiński, Piotr J. and Kollosche, Matthias and G{\´o}rski, Krzysztof and Pietraszkiewicz, Marek and Geßner, Andr{\´e} and L{\"o}hmannsr{\"o}ben, Hans-Gerd},
  title     = {Elastic FRET sensors for contactless pressure measurement},
  series = {RSC Advances : an international journal to further the chemical sciences},
  volume    = {7},
  journal   = {RSC Advances : an international journal to further the chemical sciences},
  publisher = {RSC Publishing},
  address   = {Cambridge},
  issn      = {2046-2069},
  doi       = {10.1039/c7ra06379b},
  pages     = {50578 -- 50583},
  year      = {2017},
  abstract  = {Contactless pressure monitoring based on Forster resonance energy transfer between donor/acceptor pairs immobilized within elastomers is demonstrated. The donor/acceptor energy transfer is employed by dispersing terbium(III) tris[(2-hydroxybenzoyl)-2-aminoethyl] amine complex (LLC, donor) and CdSe/ZnS quantum dots (QD655, acceptor) in styrene-ethylene/buthylene-styrene (SEBS) and poly(dimethylsiloxane) (PDMS). The continuous monitoring of QD luminescence showed a reversible intensity change as the pressure signal is alternated between two stable states indicating a pressure sensitivity of 6350 cps kPa(-1). Time-resolved measurements show the pressure impact on the FRET signal due to an increase of decay time (270 ms up to 420 ms) for the donor signal and parallel drop of decay time (170 mu s to 155 mu s) for the acceptor signal as the net pressure applied. The LLC/QD655 sensors enable a contactless readout as well as space resolved monitoring to enable miniaturization towards smaller integrated stretchable opto-electronics. Elastic FRET sensors can potentially lead to developing profitable analysis systems capable to outdo conventional wired electronic systems (inductive, capacitive, ultrasonic and photoelectric sensors) especially for point-of-care diagnostics, biological monitoring required for wearable electronics.},
  language  = {en}
}
@misc{PerovicQinOschatz2020,
  author    = {Perovic, Milena and Qin, Qing and Oschatz, Martin},
  title     = {From molecular precursors to nanoparticles},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-51614},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-516140},
  pages     = {23},
  year      = {2020},
  abstract  = {Nanoporous carbon materials (NCMs) provide the "function" of high specific surface area and thus have large interface area for interactions with surrounding species, which is of particular importance in applications related to adsorption processes. The strength and mechanism of adsorption depend on the pore architecture of the NCMs. In addition, chemical functionalization can be used to induce changes of electron density and/or electron density distribution in the pore walls, thus further modifying the interactions between carbons and guest species. Typical approaches for functionalization of nanoporous materials with regular atomic construction like porous silica, metal-organic frameworks, or zeolites, cannot be applied to NCMs due to their less defined local atomic construction and abundant defects. Therefore, synthetic strategies that offer a higher degree of control over the process of functionalization are needed. Synthetic approaches for covalent functionalization of NCMs, that is, for the incorporation of heteroatoms into the carbon backbone, are critically reviewed with a special focus on strategies following the concept "from molecules to materials." Approaches for coordinative functionalization with metallic species, and the functionalization by nanocomposite formation between pristine carbon materials and heteroatom-containing carbons, are introduced as well. Particular focus is given to the influences of these functionalizations in adsorption-related applications.},
  language  = {en}
}
@article{GaebelBeinMathaueretal.2021,
  author    = {Gaebel, Tina and Bein, Daniel and Mathauer, Daniel and Utecht, Manuel and Palmer, Richard E. and Klamroth, Tillmann},
  title     = {Nonlocal STM manipulation of chlorobenzene on Si(111)-7 x 7},
  series = {The journal of physical chemistry : C, Nanomaterials and interfaces},
  volume    = {125},
  journal   = {The journal of physical chemistry : C, Nanomaterials and interfaces},
  number    = {22},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {1932-7447},
  doi       = {10.1021/acs.jpcc.1c02612},
  pages     = {12175 -- 12184},
  year      = {2021},
  abstract  = {We use quantum chemical cluster models together with constrained density STM Ph CI functional theory (DFT) and ab initio molecular dynamics (AIMD) for open system to simulate tip and rationalize nonlocal scanning tunneling microscope (STM) manipulation experiments for Philh ci chlorobenzene (PhCl) on a Si(111)-7 X 7 surface. We consider three different processes, namely, the electron-induced dissociation of the carbon-chlorine bond for physisorbed PhCl molecules at low temperatures and the electron- or hole-induced desorption of chemisorbed PhCl at 300 K. All processes can be induced nonlocally, i.e., up to several nanometers (nm) away from the injection site, in STM experiments. We rationalize and explain the experimental findings regarding the STM-induced dissociation using constrained DFT. The coupling of STM-induced ion resonances to nuclear degrees of freedom is simulated with AIMD using the Gadzuk averaging approach for open systems. From this data, we predict a 4 fs lifetime for the cationic resonance. For the anion model, desorption could not be observed. In addition, the same cluster models are used for transition-state theory calculations, which are compared to and validated against time-lapse STM experiments.},
  language  = {en}
}
@article{EbelBald2022,
  author    = {Ebel, Kenny and Bald, Ilko},
  title     = {Low-energy (5-20 eV) electron-induced single and double strand breaks in well-defined DNA sequences},
  series = {The journal of physical chemistry letters / American Chemical Society},
  volume    = {13},
  journal   = {The journal of physical chemistry letters / American Chemical Society},
  number    = {22},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {1948-7185},
  doi       = {10.1021/acs.jpclett.2c00684},
  pages     = {4871 -- 4876},
  year      = {2022},
  abstract  = {Ionizing radiation is used in cancer radiation therapy to effectively damage the DNA of tumors. The main damage is due to generation of highly reactive secondary species such as low-energy electrons (LEEs). The accurate quantification of DNA radiation damage of well-defined DNA target sequences in terms of absolute cross sections for LEE-induced DNA strand breaks is possible by the DNA origami technique; however, to date, it is possible only for DNA single strands. In the present work DNA double strand breaks in the DNA sequence 5'-d(CAC)(4)/5'd(GTG)(4) are compared with DNA single strand breaks in the oligonucleotides 5'-d(CAC)(4) and 5'-d(GTG)(4) upon irradiation with LEEs in the energy range from 5 to 20 eV. A maximum of strand break cross section was found around 7 and 10 eV independent of the DNA sequence, indicating that dissociative electron attachment is the underlying mechanism of strand breakage and confirming previous studies using plasmid DNA.},
  language  = {en}
}
@phdthesis{Latza2020,
  author    = {Latza, Victoria Maria},
  title     = {Interactions involving lipid-based surfaces},
  doi       = {10.25932/publishup-44559},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-445593},
  school      = {Universit{\"a}t Potsdam},
  pages     = {217},
  year      = {2020},
  abstract  = {Interactions involving biological interfaces such as lipid-based membranes are of paramount importance for all life processes. The same also applies to artificial interfaces to which biological matter is exposed, for example the surfaces of drug delivery systems or implants. This thesis deals with the two main types of interface interactions, namely (i) interactions between a single interface and the molecular components of the surrounding aqueous medium and (ii) interactions between two interfaces. Each type is investigated with regard to an important scientific problem in the fields of biotechnology and biology: 1.) The adsorption of proteins to surfaces functionalized with hydrophilic polymer brushes; a process of great biomedical relevance in context with harmful foreign-body-response to implants and drug delivery systems. 2.) The influence of glycolipids on the interaction between lipid membranes; a hitherto largely unexplored phenomenon with potentially great biological relevance. Both problems are addressed with the help of (quasi-)planar, lipid-based model surfaces in combination with x-ray and neutron scattering techniques which yield detailed structural insights into the interaction processes. Regarding the adsorption of proteins to brush-functionalized surfaces, the first scenario considered is the exposure of the surfaces to human blood serum containing a multitude of protein species. Significant blood protein adsorption was observed despite the functionalization, which is commonly believed to act as a protein repellent. The adsorption consists of two distinct modes, namely strong adsorption to the brush grafting surface and weak adsorption to the brush itself. The second aspect investigated was the fate of the brush-functionalized surfaces when exposed to aqueous media containing immune proteins (antibodies) against the brush polymer, an emerging problem in current biomedical applications. To this end, it was found that antibody binding cannot be prevented by variation of the brush grafting density or the polymer length. This result motivates the search for alternative, strictly non-antigenic brush chemistries. With respect to the influence of glycolipids on the interaction between lipid membranes, this thesis focused on the glycolipids' ability to crosslink and thereby to tightly attract adjacent membranes. This adherence is due to preferential saccharide-saccharide interactions occurring among the glycolipid headgroups. This phenomenon had previously been described for lipids with special oligo-saccharide motifs. Here, it was investigated how common this phenomenon is among glycolipids with a variety of more abundant saccharide-headgroups. It was found that glycolipid-induced membrane crosslinking is equally observed for some of these abundant glycolipid types, strongly suggesting that this under-explored phenomenon is potentially of great biological relevance.},
  language  = {en}
}
@misc{NoechelReddyWangetal.2015,
  author    = {N{\"o}chel, Ulrich and Reddy, Chaganti Srinivasa and Wang, Ke and Cui, Jing and Zizak, Ivo and Behl, Marc and Kratz, Karl and Lendlein, Andreas},
  title     = {Nanostructural changes in crystallizable controlling units determine the temperature-memory of polymers},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-81124},
  pages     = {8284 -- 8293},
  year      = {2015},
  abstract  = {Temperature-memory polymers remember the temperature, where they were deformed recently, enabled by broad thermal transitions. In this study, we explored a series of crosslinked poly[ethylene-co-(vinyl acetate)] networks (cPEVAs) comprising crystallizable polyethylene (PE) controlling units exhibiting a pronounced temperature-memory effect (TME) between 16 and 99 °C related to a broad melting transition (∼100 °C). The nanostructural changes in such cPEVAs during programming and activation of the TME were analyzed via in situ X-ray scattering and specific annealing experiments. Different contributions to the mechanism of memorizing high or low deformation temperatures (Tdeform) were observed in cPEVA, which can be associated to the average PE crystal sizes. At high deformation temperatures (>50 °C), newly formed PE crystals, which are established during cooling when fixing the temporary shape, dominated the TME mechanism. In contrast, at low Tdeform (<50 °C), corresponding to a cold drawing scenario, the deformation led preferably to a disruption of existing large crystals into smaller ones, which then fix the temporary shape upon cooling. The observed mechanism of memorizing a deformation temperature might enable the prediction of the TME behavior and the knowledge based design of other TMPs with crystallizable controlling units.},
  language  = {en}
}
@article{NoechelReddyWangetal.2015,
  author    = {N{\"o}chel, Ulrich and Reddy, Chaganti Srinivasa and Wang, Ke and Cui, Jing and Zizak, Ivo and Behl, Marc and Kratz, Karl and Lendlein, Andreas},
  title     = {Nanostructural changes in crystallizable controlling units determine the temperature-memory of polymers},
  series = {Journal of Materials Chemistry A, Materials for energy and sustainability},
  volume    = {16},
  journal   = {Journal of Materials Chemistry A, Materials for energy and sustainability},
  number    = {3},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {2050-7488},
  doi       = {10.1039/c4ta06586g},
  pages     = {8284 -- 8293},
  year      = {2015},
  abstract  = {Temperature-memory polymers remember the temperature, where they were deformed recently, enabled by broad thermal transitions. In this study, we explored a series of crosslinked poly[ethylene-co-(vinyl acetate)] networks (cPEVAs) comprising crystallizable polyethylene (PE) controlling units exhibiting a pronounced temperature-memory effect (TME) between 16 and 99 °C related to a broad melting transition (∼100 °C). The nanostructural changes in such cPEVAs during programming and activation of the TME were analyzed via in situ X-ray scattering and specific annealing experiments. Different contributions to the mechanism of memorizing high or low deformation temperatures (Tdeform) were observed in cPEVA, which can be associated to the average PE crystal sizes. At high deformation temperatures (>50 °C), newly formed PE crystals, which are established during cooling when fixing the temporary shape, dominated the TME mechanism. In contrast, at low Tdeform (<50 °C), corresponding to a cold drawing scenario, the deformation led preferably to a disruption of existing large crystals into smaller ones, which then fix the temporary shape upon cooling. The observed mechanism of memorizing a deformation temperature might enable the prediction of the TME behavior and the knowledge based design of other TMPs with crystallizable controlling units.},
  language  = {en}
}
@article{YestePrimusAlcantaraetal.2020,
  author    = {Yeste, Maria Pilar and Primus, Philipp-Alexander and Alcantara, Rodrigo and Cauqui, Miguel Angel and Calvino, Juan Jose and Pintado, Jos{\´e} Mar{\´i}a and Blanco, Ginesa},
  title     = {Surface characterization of two Ce0.62Zr0.38O2 mixed oxides with different reducibility},
  series = {Applied surface science : a journal devoted to applied physics and chemistry of surfaces and interfaces},
  volume    = {503},
  journal   = {Applied surface science : a journal devoted to applied physics and chemistry of surfaces and interfaces},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0169-4332},
  doi       = {10.1016/j.apsusc.2019.144255},
  pages     = {9},
  year      = {2020},
  abstract  = {This paper presents a study of the surface properties of two Ce/Zr mixed oxides with different reducibility, obtained by applying distinct thermal ageing treatments to an oxide with the composition Ce0.62Zr0.38O2. The surface composition was investigated by XPS. Chemical reactivity of the surface was studied by adsorption of the probe molecules CO2, D-2 and methanol. Nanostructural characterization was carried out by XRD, Raman and high-resolution Eu3+ spectroscopy (FLNS). The characterization showed only slight variations in surface composition and bulk Ce-Zr distribution, but hardy differences concerning the type and strength of acidic surface centres, as well as strong differences in the ability to dissociate hydrogen. Structural variations between both samples were identified by comparing the optical spectra of Eu3+ in surface doped samples.},
  language  = {en}
}
@article{BastianYudeGuerenuKurganovaetal.2020,
  author    = {Bastian, Philipp U. and Yu, Leixiao and de Guere{\~n}u Kurganova, Anna Lopez and Haag, Rainer and Kumke, Michael Uwe},
  title     = {Bioinspired confinement of upconversion nanoparticles for improved performance in aqueous solution},
  series = {The journal of physical chemistry : C, Nanomaterials and interfaces},
  volume    = {124},
  journal   = {The journal of physical chemistry : C, Nanomaterials and interfaces},
  number    = {52},
  publisher = {American Chemical Society},
  address   = {Washington, DC},
  issn      = {1932-7447},
  doi       = {10.1021/acs.jpcc.0c09798},
  pages     = {28623 -- 28635},
  year      = {2020},
  abstract  = {The resonance energy transfer (RET) from NaYF4:Yb,Er upconverting nanoparticles (UNCPs) to a dye (5-carboxytetramethylrhodamine (TAMRA)) was investigated by photoluminescence experiments and microscale thermophoresis (MST). The dye was excited via RET from the UCNPs which was excited in the near-infrared (NIR). The change of the dye diffusion speed (free vs coupled) was investigated by MST. RET shows significant changes in the decay times of the dye as well as of the UCNPs. MST reveals significant changes in the diffusion speed. A unique amphiphilic coating polymer (customized mussel protein (CMP) polymer) for UCNP surface coating was used, which mimics blood protein adsorption and mussel food protein adhesion to transfer the UCNP into the aqueous phase and to allow surface functionalization. The CMP provides very good water dispersibility to the UCNPs and minimizes ligand exchange and subsequent UCNP aging reactions because of the interlinkage of the CMP on the UCNP surface. Moreover, CMP provides N-3-functional groups for dick chemistry-based functionalization demonstrated with the dye 5-carboxytetramethylrhodamine (TAMRA). This establishes the principle coupling scheme for suitable biomarkers such as antibodies. The CMP provides very stable aqueous UCNP dispersions that are storable up to 3 years in a fridge at 5 degrees C without dissolution or coagulation. The outstanding properties of CMP in shielding the UCNP from unwanted solvent effects is reflected in the distinct increase of the photoluminescence decay times after UCNP functionalization. The UCNP-to-TAMRA energy transfer is also spectroscopically investigated at low temperatures (4-200 K), revealing that one of the two green Er(III) emission bands contributes the major part to the energy transfer. The TAMRA fluorescence decay time increases by a factor of 9500 from 2.28 ns up to 22 mu s due to radiationless energy transfer from the UCNP after NIR excitation of the latter. This underlines the unique properties of CMP as a versatile capping ligand for distinctly improving the UCNPs' performance in aqueous solutions, for coupling of biomolecules, and for applications for in vitro and in vivo experiments using UCNPs as optical probes in life science applications.},
  language  = {en}
}
@article{FischerAndersSaalfrank2022,
  author    = {Fischer, Eric Wolfgang and Anders, Janet and Saalfrank, Peter},
  title     = {Cavity-altered thermal isomerization rates and dynamical resonant localization in vibro-polaritonic chemistry},
  series = {The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr},
  volume    = {156},
  journal   = {The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr},
  number    = {15},
  publisher = {American Institute of Physics},
  address   = {Melville, NY},
  issn      = {0021-9606},
  doi       = {10.1063/5.0076434},
  pages     = {16},
  year      = {2022},
  abstract  = {It has been experimentally demonstrated that reaction rates for molecules embedded in microfluidic optical cavities are altered when compared to rates observed under "ordinary" reaction conditions. However, precise mechanisms of how strong coupling of an optical cavity mode to molecular vibrations affects the reactivity and how resonance behavior emerges are still under dispute. In the present work, we approach these mechanistic issues from the perspective of a thermal model reaction, the inversion of ammonia along the umbrella mode, in the presence of a single-cavity mode of varying frequency and coupling strength. A topological analysis of the related cavity Born-Oppenheimer potential energy surface in combination with quantum mechanical and transition state theory rate calculations reveals two quantum effects, leading to decelerated reaction rates in qualitative agreement with experiments: the stiffening of quantized modes perpendicular to the reaction path at the transition state, which reduces the number of thermally accessible reaction channels, and the broadening of the barrier region, which attenuates tunneling. We find these two effects to be very robust in a fluctuating environment, causing statistical variations of potential parameters, such as the barrier height. Furthermore, by solving the time-dependent Schrodinger equation in the vibrational strong coupling regime, we identify a resonance behavior, in qualitative agreement with experimental and earlier theoretical work. The latter manifests as reduced reaction probability when the cavity frequency omega(c) is tuned resonant to a molecular reactant frequency. We find this effect to be based on the dynamical localization of the vibro-polaritonic wavepacket in the reactant well.},
  language  = {en}
}
@article{SchuermannNagelJuergensenetal.2022,
  author    = {Sch{\"u}rmann, Robin and Nagel, Alessandro and Juergensen, Sabrina and Pathak, Anisha and Reich, Stephanie and Pacholski, Claudia and Bald, Ilko},
  title     = {Microscopic understanding of reaction rates observed in plasmon chemistry of nanoparticle-ligand systems},
  series = {The journal of physical chemistry : C, Nanomaterials and interfaces},
  volume    = {126},
  journal   = {The journal of physical chemistry : C, Nanomaterials and interfaces},
  number    = {11},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {1932-7447},
  doi       = {10.1021/acs.jpcc.2c00278},
  pages     = {5333 -- 5342},
  year      = {2022},
  abstract  = {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.},
  language  = {en}
}
@article{FriessLendleinWischke2021,
  author    = {Frieß, Fabian and Lendlein, Andreas and Wischke, Christian},
  title     = {Switching microobjects from low to high aspect ratios using a shape-memory effect},
  series = {Soft matter},
  volume    = {17},
  journal   = {Soft matter},
  number    = {41},
  publisher = {Royal Society of Chemistry},
  address   = {London},
  issn      = {1744-6848},
  doi       = {10.1039/d1sm00947h},
  pages     = {9326 -- 9331},
  year      = {2021},
  abstract  = {Spherical particles from shape-memory polymers (SMP) can be stretched to ellipsoids with high aspect ratio (AR) and temporarily stabilized. They can switch back to low AR upon thermal stimulation. Here, the creation of an alternative shape-switching capability of particles from low to high AR is introduced, where a SMP matrix from polyvinyl alcohol (PVA) is used to create crosslinked high AR particles and to program the embedded micrometer-sized particles from a second SMP (oligo(epsilon-caprolactone) micronetworks, MN) with a low switching temperature T-sw. This programming proceeds through shape-recovery of the PVA matrix, from which the MN are harvested by PVA matrix dissolution. The use of a dissolvable SMP matrix may be a general strategy to efficiently create systems with complex moving capabilities.},
  language  = {en}
}
@article{WojcikBrinkmannZduneketal.2020,
  author    = {Wojcik, Michal and Brinkmann, Pia and Zdunek, Rafał and Riebe, Daniel and Beitz, Toralf and Merk, Sven and Cieslik, Katarzyna and Mory, David and Antonczak, Arkadiusz},
  title     = {Classification of copper minerals by handheld laser-induced breakdown spectroscopy and nonnegative tensor factorisation},
  series = {Sensors},
  volume    = {20},
  journal   = {Sensors},
  number    = {18},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1424-8220},
  doi       = {10.3390/s20185152},
  pages     = {17},
  year      = {2020},
  abstract  = {Laser-induced breakdown spectroscopy (LIBS) analysers are becoming increasingly common for material classification purposes. However, to achieve good classification accuracy, mostly noncompact units are used based on their stability and reproducibility. In addition, computational algorithms that require significant hardware resources are commonly applied. For performing measurement campaigns in hard-to-access environments, such as mining sites, there is a need for compact, portable, or even handheld devices capable of reaching high measurement accuracy. The optics and hardware of small (i.e., handheld) devices are limited by space and power consumption and require a compromise of the achievable spectral quality. As long as the size of such a device is a major constraint, the software is the primary field for improvement. In this study, we propose a novel combination of handheld LIBS with non-negative tensor factorisation to investigate its classification capabilities of copper minerals. The proposed approach is based on the extraction of source spectra for each mineral (with the use of tensor methods) and their labelling based on the percentage contribution within the dataset. These latent spectra are then used in a regression model for validation purposes. The application of such an approach leads to an increase in the classification score by approximately 5\% compared to that obtained using commonly used classifiers such as support vector machines, linear discriminant analysis, and the k-nearest neighbours algorithm.},
  language  = {en}
}
@article{FischerWertherBouaklineetal.2020,
  author    = {Fischer, Eric W. and Werther, Michael and Bouakline, Foudhil and Saalfrank, Peter},
  title     = {A hierarchical effective mode approach to phonon-driven multilevel vibrational relaxation dynamics at surfaces},
  series = {The journal of chemical physics : bridges a gap between journals of physics and journals of chemistry},
  volume    = {153},
  journal   = {The journal of chemical physics : bridges a gap between journals of physics and journals of chemistry},
  number    = {6},
  publisher = {American Institute of Physics},
  address   = {Melville},
  issn      = {0021-9606},
  doi       = {10.1063/5.0017716},
  pages     = {15},
  year      = {2020},
  abstract  = {We discuss an efficient Hierarchical Effective Mode (HEM) representation of a high-dimensional harmonic oscillator bath, which describes phonon-driven vibrational relaxation of an adsorbate-surface system, namely, deuterium adsorbed on Si(100). Starting from the original Hamiltonian of the adsorbate-surface system, the HEM representation is constructed via iterative orthogonal transformations, which are efficiently implemented with Householder matrices. The detailed description of the HEM representation and its construction are given in the second quantization representation. The hierarchical nature of this representation allows access to the exact quantum dynamics of the adsorbate-surface system over finite time intervals, controllable via the truncation order of the hierarchy. To study the convergence properties of the effective mode representation, we solve the time-dependent Schrodinger equation of the truncated system-bath HEM Hamiltonian, with the help of the multilayer extension of the Multiconfigurational Time-Dependent Hartree (ML-MCTDH) method. The results of the HEM representation are compared with those obtained with a quantum-mechanical tier-model. The convergence of the HEM representation with respect to the truncation order of the hierarchy is discussed for different initial conditions of the adsorbate-surface system. The combination of the HEM representation with the ML-MCTDH method provides information on the time evolution of the system (adsorbate) and multiple effective modes of the bath (surface). This permits insight into mechanisms of vibration-phonon coupling of the adsorbate-surface system, as well as inter-mode couplings of the effective bath.},
  language  = {en}
}
@article{DoeringGrigorievTapioetal.2022,
  author    = {Doering, Ulrike and Grigoriev, Dmitry and Tapio, Kosti and Bald, Ilko and B{\"o}ker, Alexander},
  title     = {Synthesis of nanostructured protein-mineral-microcapsules by sonication},
  series = {Soft matter},
  volume    = {18},
  journal   = {Soft matter},
  number    = {13},
  publisher = {Royal Society of Chemistry},
  address   = {London},
  issn      = {1744-6848},
  doi       = {10.1039/d1sm01638e},
  pages     = {2558 -- 2568},
  year      = {2022},
  abstract  = {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.},
  language  = {en}
}
@article{IhlenburgMaiThuenemannetal.2021,
  author    = {Ihlenburg, Ramona and Mai, Tobias and Th{\"u}nemann, Andreas F. and Baerenwald, Ruth and Saalw{\"a}chter, Kay and Koetz, Joachim and Taubert, Andreas},
  title     = {Sulfobetaine hydrogels with a complex multilength-scale hierarchical structure},
  series = {The journal of physical chemistry : B, Condensed matter, materials, surfaces, interfaces \& biophysical chemistry},
  volume    = {125},
  journal   = {The journal of physical chemistry : B, Condensed matter, materials, surfaces, interfaces \& biophysical chemistry},
  number    = {13},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {1520-6106},
  doi       = {10.1021/acs.jpcb.0c10601},
  pages     = {3398 -- 3408},
  year      = {2021},
  abstract  = {Hydrogels with a hierarchical structure were prepared from a new highly water-soluble crosslinker N,N,N',N'-tetramethyl-N,N'-bis(2-ethylmethacrylate)-propyl-1,3-diammonium dibromide and from the sulfobetaine monomer 2-(N-3-sulfopropyl-N,N-dimethyl ammonium)ethyl methacrylate. The free radical polymerization of the two compounds is rapid and yields near-transparent hydrogels with sizes up to 5 cm in diameter. Rheology shows a clear correlation between the monomer-to-crosslinker ratio and the storage and loss moduli of the hydrogels. Cryo-scanning electron microscopy, low-field nuclear magnetic resonance (NMR) spectroscopy, and small-angle X-ray scattering show that the gels have a hierarchical structure with features spanning the nanometer to the sub-millimeter scale. The NMR study is challenged by the marked inhomogeneity of the gels and the complex chemical structure of the sulfobetaine monomer. NMR spectroscopy shows how these complications can be addressed via a novel fitting approach that considers the mobility gradient along the side chain of methacrylate-based monomers.},
  language  = {en}
}