A5074615411- Surfactants and Colloidal Systems
- Electrostatics and Colloid Interactions
- Advanced Polymer Synthesis and Characterization
- Gold and Silver Nanoparticles Synthesis and Applications
- Wood Treatment and Properties
- Food Chemistry and Fat Analysis
- Bamboo properties and applications
- Thermal Radiation and Cooling Technologies
- Chemical and Physical Properties in Aqueous Solutions
- Advanced Theoretical and Applied Studies in Material Sciences and Geometry
- Proteins in Food Systems
- Ubiquitin and proteasome pathways
- nanoparticles nucleation surface interactions
- Textile materials and evaluations
- Peptidase Inhibition and Analysis
- Material Properties and Processing
- Photochromic and Fluorescence Chemistry
- Advanced Cellulose Research Studies
- Plasmonic and Surface Plasmon Research
- Nanofluid Flow and Heat Transfer
- Polymer Surface Interaction Studies
- Enzyme Structure and Function
- Polymer Nanocomposites and Properties
- Spectroscopy and Quantum Chemical Studies
- Photonic Crystals and Applications
Institut Laue-Langevin
2017-2020
Paderborn University
2017-2019
University of Bayreuth
2017
Abstract Wood and other cellulosic materials are highly sensitive to changes in moisture content, which affects their use most applications. We investigated the effects of on nanoscale structure wood using X-ray neutron scattering, complemented by dynamic vapor sorption. The studied set samples included tension normal hardwood as well representatives two softwood species. Their nanostructure was characterized wet state before after first drying at relative humidities between 15 90%....
Colloidal assemblies of phospholipids in oil are known to be highly sensitive changes system composition and temperature. Despite the fundamental biological high industrial relevance these aggregates, mechanisms behind structural changes, especially real oils, not well understood. In this work, small-angle X-ray scattering (SAXS) was combined with molecular dynamics simulations characterize effects oleic acid, water, temperature on self-assembled structures formed by lecithin rapeseed oil....
In this work we investigate the salt-induced cluster formation of monodisperse, spherical gold nanoparticles possessing negative surface charge. Time dependent dynamic light scattering was used to determine critical coagulation concentration and study kinetics growth. Cryo-TEM as well small angle X-ray allowed obtain insights into morphology at various salt concentrations. The time growth monitored by stopped-flow experiments UV-Visible extinction measurements simultaneously. Our results...
Complexes between the anionic polyelectrolyte sodium polyacrylate (PA) and an oppositely charged divalent azobenzene dye are prepared in aqueous solution. Depending on ratio stable aggregates with a well-defined spherical shape observed. Upon exposure of these complexes to UV light, trans → cis transition is excited resulting better solubility dissolution complexes. The PA chains reassemble into when allowed relax back isomer. Varying temperature during this reformation step has direct...
Dilute solutions of sodium poly(styrene sulfonate) (NaPSS) in the presence Al3+, Ca2+, and Ba2+ were analysed by means isothermal titration calorimetry (ITC) order to investigate heat effect bond formation between those cations anionic SO3− residues NaPSS. The selection was guided solution behavior corresponding PSS salts from a preceding study [M. Hansch et al., J. Chem. Phys. 148(1), 014901 (2018)], where bonds showed an increasing solubility with decreasing temperature Al3+ exhibited...
Periodic superstructures of plasmonic nanoparticles have attracted significant interest because they can support coupled modes, making them interesting for lasing, metamaterials, and as light-management structures in thin-film optoelectronic devices. We recently shown that noble metal hydrogel core-shell colloids allow the fabrication highly ordered 2-dimensional lattices show surface lattice resonances result plasmonic/diffractive coupling (Volk, K.; Fitzgerald, J. P. S.; Ruckdeschel, P.;...
Abstract Block copolymers were prepared with two anionic polyelectrolyte blocks: sodium polyacrylate (PA) and polystyrene sulfonate (PSS), in order to investigate their phase behavior aqueous solution the presence of Ca 2+ cations. Depending on concentration polymer ratio block lengths copolymer, spherical micelles observed. Micelle formation arises from specific interaction PA only. An extensive small-angle scattering study was performed unravel structure dimensions copolymer micelles....
The proteasome is a key player of regulated protein degradation in all kingdoms life. Although recent atomic structures have provided snapshots on number conformations, data substrate states and populations during the active process solution remain scarce. Here, we use time-resolved small-angle neutron scattering deuterium-labeled GFPssrA an unlabeled archaeal PAN-20S system to obtain direct structural information ATP-driven unfolding subsequent proteolysis solution. We find that native are...
This work presents well-defined and switchable micelles of block copolymers consisting the two anionic polyelectrolytes sodium polyacrylate (NaPA) polystyrene sulfonate (NaPSS). Micellization occurs due to specific binding Ca2+ acrylate groups, which results in neutralization corresponding thereby formation hydrophobic core micelles. In contrast, PSS remains charged forms stabilizing shell. is triggered by variations concentration or temperature a fully reversible repeatable process....
Polyelectrolytes show diverse ion-specific effects with a wide variety of ions. In the present work, we study solution behavior diblock copolymers polyacrylate (PA) and polystyrenesulfonate (PSS) blocks in presence earth alkaline cations Ca2+, Sr2+, Ba2+. Micellization can be triggered by variation temperature. For this micelle formation occurs at high temperatures, while for Sr2+ Ba2+, it low temperatures an intermediate temperature regime single chains. Small-angle neutron scattering on...
The motion of core-shell colloids during laser heating is studied using angle-dependent pump-probe dynamic light scattering. cores consist a single spherical gold nanoparticle whose localized surface plasmon resonance has strong spectral overlap with the wavelength pump laser. They are homogeneously encapsulated in thick hydrogel shells composed either chemically cross-linked poly-N-isopropylacrylamide or poly[2-(2-methoxyethoxy)ethyl methacrylate], both which exhibit temperature-dependent...