A5039014018- Semiconductor materials and devices
- Spectroscopy and Quantum Chemical Studies
- Advanced Chemical Physics Studies
- Quantum, superfluid, helium dynamics
- Copper Interconnects and Reliability
- Machine Learning in Materials Science
- NMR spectroscopy and applications
- Metal and Thin Film Mechanics
- Spectroscopy and Laser Applications
- Chemical and Physical Properties of Materials
- Plasma Diagnostics and Applications
- Diamond and Carbon-based Materials Research
- Electron and X-Ray Spectroscopy Techniques
- Catalytic Processes in Materials Science
- Advancements in Photolithography Techniques
- Corrosion Behavior and Inhibition
- Thermal and Kinetic Analysis
- X-ray Diffraction in Crystallography
- Mesoporous Materials and Catalysis
- Ammonia Synthesis and Nitrogen Reduction
- Synthesis and properties of polymers
- Computational Physics and Python Applications
- Advancements in Semiconductor Devices and Circuit Design
- Metal-Organic Frameworks: Synthesis and Applications
- Block Copolymer Self-Assembly
Paderborn University
2019-2024
Density functional theory-based molecular dynamics simulations are increasingly being used for simulating aqueous interfaces. Nonetheless, the choice of appropriate density functional, critically affecting outcome simulation, has remained arbitrary. Here, we assess performance various exchange–correlation (XC) functionals, based on metrics relevant to sum-frequency generation spectroscopy. The structure and water at water–air interface governed by heterogeneous intermolecular interactions,...
Disordered molecular systems, such as amorphous catalysts, organic thin films, electrolyte solutions, and water, are at the cutting edge of computational exploration present. Traditional simulations systems length scales relevant to experiments in practice require a compromise between model accuracy quality sampling. To address this problem, we have developed an approach based on generative machine learning called Morphological Autoregressive Protocol (MAP), which provides access mesoscale...
Abstract CPO‐27 is a metal‐organic framework (MOF) with coordinatively unsaturated metal centers (open sites). It therefore an ideal host material for small guest molecules, including water. This opens up numerous possible applications, such as proton conduction, humidity sensing, water harvesting, or adsorption‐driven heat pumps. For all of these profound knowledge the adsorption and desorption in micropores mandatory. The hydration structure CPO‐27‐ M ( = Zn Cu) investigated using vapor...
Abstract In the spatial confinement of cylindrical mesopores with diameters a few nanometers, water molecules experience restrictions in hydrogen bonding. This leads to different behavior regarding molecular orientational freedom (‘structure water') compared bulk liquid state. addition pore size, is also strongly affected by strength wall‐to‐water interactions, that is, wall polarity. this work, studied both experimentally and theoretically. The surface polarity mesoporous silica (SiO 2 )...
We have examined the impact of intermolecular vibrational coupling effects O-H stretch modes, as obtained by surface-specific velocity-velocity correlation function approach, on simulated sum-frequency generation spectra water/air interface. Our study shows that inclusion within first three water layers, i.e. from interface up to a distance 6 Å towards bulk, is essential reproduce experimental SFG spectra. In particular, we find these contributions are dominated between active interfacial...
Abstract This feature article presents recent results on the analysis of plasma/polymer interactions and nucleation ultra‐thin plasma films polymeric substrates. Because their high importance for understanding such processes, in situ analytical approaches volume as well plasma/substrate interfaces are introduced before findings surface chemistry. The activation substrates is divided into fundamental processes model relevance polymer complexity. Concerning thin film growth, both...
Abstract Vapor phase infiltration (VPI) has emerged as a promising tool for fabrication of novel hybrid materials. In the field polymeric gas separation membranes, beneficial impact on stability and membrane performance is known several polymers with differing functional groups. This study first time investigates VPI trimethylaluminum (TMA) into poly(1‐trimethylsilyl‐1‐propyne) (PTMSP), featuring carbon–carbon double bond group. Saturation precursor inside polymer already attained after 60 s...
The vapor phase infiltration (VPI) process of trimethyl aluminum (TMA) into poly(4-acetoxystyrene) (POAcSt), poly(nonyl methacrylate) (PNMA) and poly(tert-butyl (PtBMA) is reported. Depth-profiling X-ray photoelectron spectroscopy (XPS) measurements are used for the first time VPI based hybrid materials to determine content over polymer film thickness. An understanding reaction mechanism on interaction TMA infiltrating different polymers was obtained through infrared (IR) supported by...
In this work, second-generation Car–Parrinello-based mixed quantum-classical mechanics molecular dynamics simulations of small nanoparticles NbP, NbAs, TaAs, and 1T-TaS2 in water are presented. The first three materials topological Weyl semimetals, which were recently discovered to be active catalysts photocatalytic splitting. aim research was correlate potential differences the structure vicinity nanoparticle surface with activity these light induced proton reduction. results presented...
We have applied path-integral molecular dynamics simulations to investigate the impact of nuclear quantum effects on vibrational water molecules at water–air interface. The instantaneous fluctuations in frequencies O–H stretch modes are calculated using wavelet method time series analysis, while scales spectral diffusion determined from frequency-time correlation functions and joint probability distributions. find that inclusion leads not only a redshift frequency distribution by about 120...
Abstract Here we show a novel approach to characterize the gas transfer behavior of silicon-oxide (SiO x ) coatings and explain underlying dynamics. For this, investigate coating on nm-scale both by measurement simulation. Positron annihilation spectroscopy (PAS) quantum mechanical electronic structure-based molecular dynamics simulations are combined porous landscape SiO coatings. This analyses influence micropores smaller than 2 nm in diameter permeation which difficult study with...
This feature article presents insights concerning the correlation of PECVD and PEALD thin film structures with their barrier or membrane properties. While in principle similar precursor gases processes can be applied, adjustment deposition parameters for different polymer substrates lead to either an effective diffusion selective permeabilities. In both cases understanding growth analysis pore size distribution surface chemistry is utmost importance related transport properties small...
Abstract This feature article presents insights concerning the correlation of plasma‐enhanced chemical vapor deposition and atomic layer thin film structures with their barrier or membrane properties. While in principle similar precursor gases processes can be applied, adjustment parameters for different polymer substrates lead to either an effective diffusion selective permeabilities. In both cases, understanding growth analysis pore size distribution surface chemistry is utmost importance...
We have applied path integral molecular dynamics simulations to investigate nuclear quantum effects on the vibrational of water molecules at water-air interface. The instantaneous fluctuations in frequencies O-H stretch modes are calculated using wavelet method time series analysis, while scales spectral diffusion determined from frequency-time correlation functions and joint probability distributions, as well hydrogen bond number functions. find that inclusion leads not only a redshift...
Disordered molecular systems such as amorphous catalysts, organic thin films, electrolyte solutions, and water are at the cutting edge of computational exploration today. Traditional simulations length-scales relevant to experiments in practice require a compromise between model accuracy quality sampling. To remedy situation, we have developed an approach based on generative machine learning called Morphological Autoregressive Protocol (MAP) which provides access mesoscale disordered...
This feature article considers the analysis of initial states film growth on polymer substrates. The assembled results are based cooperation between research groups in field plasma physics, chemistry, electric as well mechanical engineering over last years, mostly within frame transregional project SFB-TR 87 ("Pulsed high power plasmas for synthesis nanostructured functional layers"). aims at bridging gap understanding processes gas phase and resulting surface interface polymer. show that...
In this work, second-generation Car-Parrinello-based QM/MM molecular dynamics simulations of small nanoparticles NbP, NbAs, TaAs and 1T-TaS$_2$ in water are presented. The first three materials topological Weyl semimetals, which were recently discovered to be active catalysts photocatalytic splitting. aim research was correlate potential differences the structure vicinity nanoparticle surface with activity these light induced proton reduction. results presented herein allow explain catalytic...
Near ambient pressure X-ray photoelectron spectroscopy (XPS) in nitrogen atmosphere was utilized to investigate gas-solid interactions within porous thin films. The films were SiO 2 , and had thickness ranging from 30 75 nm. They prepared with distinctive differences terms of porosity ( i.e. dense, micro-porous meso-porous films) roughness. XPS N1s core levels the N gas presence samples showed clear variations both width binding energy. peak correlated magnitude surface charging induced...