Interfaces between water and silicates are ubiquitous relevant for, among others, geochemistry, atmospheric chemistry, chromatography. The molecular-level details of organization at silica surfaces important for a fundamental understanding this interface. While is hydrophilic, weakly hydrogen-bonded OH groups have been identified the surface silica, characterized by high O-H stretch vibrational frequency. Here, through combination experimental theoretical surface-selective spectroscopy, we...

We provide a detailed description of the structure water at interface with air (liquid-vapor LV interface) from state-of-the-art DFT-based molecular dynamics simulations. For first time, two-dimensional (2D) H-bond extended network has been identified and fully characterized, demonstrating that interfacial is organized into 2D sheet H-bonds oriented parallel to instantaneous surface following its spatial temporal oscillations. By analyzing nonlinear vSFG (vibrational sum frequency...

This work provides unambiguous definitions from theoretical simulations of the two interfacial regions named BIL (binding layer) and DL (diffuse at charged solid/water air/water interfaces. The nomenclature follows pioneering Wen et al. [Phys. Rev. Lett. 2016, 116, 016101]. Our are based on intrinsic structural properties water only. Knowing regions, one is then able to deconvolve χ(2)(ω) non-linear SFG (sum frequency generation) response into χ(ω) contributions, thus providing a detailed...

Water, being the universal solvent, acts as a competing agent in fundamental processes, such folding, aggregation or biomolecular recognition. A molecular understanding of hydrophobic hydration is central importance to subtle free energy differences, which dictate function. Ab initio and classical dynamics simulations yield two distinct water populations shell solvated tert-butanol noted "HB-wrap" "HB-hydration2bulk". The experimentally observed spectrum can be dissected into modes, centered...

Through the prism of rather controversial and elusive silica/water interface, ab initio DFT-based molecular dynamics simulations structure non-linear SFG spectroscopy interface are analysed. Following our recent work [Phys. Chem. Phys., 2018, 20, 5190-5199], we show that once interfacial water is decomposed into BIL (Binding Interfacial Layer) DL (Diffuse regions, signals can be deconvolved unambiguously interpreted, a global microscopic understanding on interfaces obtained. By comparing...

Hydrophobicity/hydrophilicity of aqueous interfaces at the molecular level results from a subtle balance in water-water and water-surface interactions. This is characterized here via density functional theory-molecular dynamics (DFT-MD) coupled with vibrational sum frequency generation (SFG) THz-IR absorption spectroscopies. We show that water interface series weakly interacting materials organized into two-dimensional hydrogen-bonded network (2D-HB-network), which also found above some...

Surface fouling induced by biomolecules and microorganisms remains a persistent challenge in materials science, particularly healthcare applications, where biofilm formation on medical devices may lead to infections antimicrobial resistance. Antifouling strategies typically rely the of either hydration layers or cytotoxic for direct effects. Recent advances zwitterionic polymers derived from ylides offer promising yet unexplored toolbox construction antifouling coatings. While N-oxide-based...

Following our recent work [Phys. Chem. Phys. 20:5190–99 (2018)] that provided the means to unambigously define and extract three water regions at any charged interface (solid–liquid air–liquid alike), denoted BIL (Binding Interfacial Layer), DL (Diffuse Layer) Bulk, how calculate their associated non-linear Sum Frequency Generation Spectroscopy (SFG) χ2(ω) spectroscopic contributions from Density Functional Theory (DFT)-based ab initio molecular dynamics simulations (DFT-MD/AIMD), we show...

Within the general context of electrochemical oxygen evolution reaction water oxidation/electrolysis, we focus on one essential aspect interfaces, i.e., comprehension interaction and organisation liquid at (semiconductor) (110)-Co3O4 surface using density functional theory-molecular dynamics simulations. A detailed characterization chemical physical properties aqueous interface is provided in terms structure, dynamics, electric field, work function, spectroscopy, as a preliminary step into...

We present a methodology to compute, at reduced computational cost, Gibbs free energies, enthalpies, and entropies of adsorption from molecular dynamics. calculate vibrational partition functions which we obtain the density states by projection on normal modes. The use set well-chosen reference structures along trajectories accounts for anharmonicities For methane, ethane, propane in H-CHA zeolite, limit our treatment modes localized site (zeolitic OH group) alkane molecule interacting with...

The drastic shape deformation that accompanies the structural phase transition in thermosalient materials offers great potential for their applications as actuators and sensors. microscopic origin of this fascinating effect has so far remained obscure, while technological applications, it is important to learn how drive transitions from one another. Here, we present a combined computational experimental study, which have successfully identified order parameter molecular crystal...

The analytical model for the study of charge mobility in molecules presented by Galimberti et al. [J. Chem. Phys. 138, 164115 (2013)] is applied to hydrogen bonded planar dimers. Atomic charges and fluxes are obtained from density functional theory computed atomic polar tensors related first derivatives, thus providing an interpretation IR intensity enhancement X–H stretching band observed upon aggregation. Our results show that both principal non-principal have important role...

Four models for the calculation of IR spectrum gas phase molecules and clusters from molecular dynamics simulations are presented with aim to reduce computational cost usual Fourier transform (FT) time correlation function dipole moment. These based on VDOS, FT velocities, atomic polar tensors (APT). The differ each other by number APTs inserted into velocities function. Excellent accuracy is achieved model adopting a weighted linear combination few selected adapted rotation molecule (model...

Zwitterionic polymers have emerged as highly attractive building blocks for antifouling coatings in biomedical applications. Notably, these offer effective alternatives to the widely used poly(ethylene glycol) (PEG), which has raised concerns regarding its immunotoxicity and development of PEG-specific antibodies. Polymeric ylides, a largely overlooked class zwitterionic polymers, been reported scaffolds. However, subclasses, poly(sulfur ylides) N-oxides, lack structural diversity chemical...

The crystal structure and the IR spectrum of crystalline poly(trimethylene terephthalate), PTT, have been investigated by means periodic density functional theory calculations including Grimme's correction for dispersion interactions. Both structural spectroscopic results critically compared to experimental data taken from literature, showing very good agreement between experiments. previous spectral assignments, based only on investigations, revised, further insights obtained. Furthermore,...

On the basis of analytical model previously suggested by Dinur, we discuss here a method for calculation vibrational charge fluxes in planar molecules, obtained as numerical second derivatives molecular dipole moment. This is consistent with partitioning atomic polar tensors into and according to Equilibrium Charges-Charge Fluxes it directly related experimentally measurable quantities such IR intensities. density functional theory calculations carried out several small benchmark complete...

Graph theory based vibrational modes as new entities for THz spectroscopy.

The paper illustrates the Activity Weighted Velocities (AWV) methodology to compute Vibrational Circular Dichroism (VCD) anharmonic spectra from Density Functional Theory (DFT) molecular dynamics. AWV calculates by Fourier Transform of time correlation functions velocities, weighted specific observables: Atomic Polar Tensors (APTs) and Axial (AATs). Indeed, shows correctly reproduce experimental for systems in gas liquid phases, both case weakly strongly interacting systems. comparison with...

To assess rubella and measles susceptibility among women of childbearing age we conducted a cross-sectional seroprevalence study in four cities one rural area Argentina. A convenience sample aged 15-49 years seeking care public health-care institutions was selected (n=2804). Serum specimens were tested for IgG antibody titres. The overall to 8.8 12.5% respectively. Seroprevalence differences found both (P<0.001) (P=0.002) across sites. Rubella higher >or=40 than younger (P=0.04). Measles...

Density functional theory calculations with periodic boundary conditions are exploited to study the infrared spectrum of crystalline polyethylene. Spectral changes lead by intermolecular packing in orthorhombic three-dimensional crystal discussed means a careful comparison carried out for an isolated polymer chain all-trans conformation, described as ideal one-dimensional crystal. The results analyzed framework “oligomer approach” through modelling IR n-alkanes different lengths....

Liquid crystals have found a wide area of application over the last few decades, proving to be excellent materials for tunable optics from visible near-infrared frequencies. Currently, much effort is devoted demonstrating their applicability at THz frequencies (1-10 THz), where tremendous advances broadband and intense sources been achieved. Yet, detailed understanding THz-triggered dynamics in liquid incomplete. Here, we perform time domain spectroscopy on 4-cyano-4'-alkyl-biphenyl (