The kinetics of a light irradiation enhanced room temperature NO gas sensor using hybrid ZnO/ZnTe nanorod structures.

This study focuses on fabricating a hybrid structure consisting of ZnO nanorods and ZnTe nanoparticles for NO gas detection, particularly exploring the impact of light irradiation at room temperature (RT). The morphology, physical characteristics, and chemical properties of the ZnO/ZnTe hybrid structure are carefully studied under diverse analytical methods such as X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and other measurements. The ZnO/ZnTe composite displayed an improved response toward 500 ppb NO under the blue light radiation effect.

Effect of the nature of the solid substrate on spatially heterogeneous activated dynamics in glass forming supported films.

We extend the force-level elastically collective nonlinear Langevin equation theory to treat the spatial gradients of the alpha relaxation time and glass transition temperature, and the corresponding film-averaged quantities, to the geometrically asymmetric case of finite thickness supported films with variable fluid-substrate coupling. The latter typically nonuniversally slows down motion near the solid-liquid interface as modeled via modification of the surface dynamic free energy caging constraints that are spatially transferred into the film and which compete with the accelerated relaxation gradient induced by the vapor interface. Quantitative applications to the foundational hard sphere fluid and a polymer melt are presented.

Toward better understanding of the high-pressure structural transformation in beryllium by the statistical moment method.

Beryllium is a vital alkaline-earth metal for plasma physics, space science, and nuclear technology. Unfortunately, its accurate phase diagram is clouded by many controversial results, even though solid beryllium can only exist with hcp or bcc crystalline structures. Herein, we offer a simple quantum-statistical solution to the above problem.

A comparative study of receptor interactions between SARS-CoV and SARS-CoV-2 from molecular modeling.

The pandemic of COVID-19 severe acute respiratory syndrome, which was fatal for millions of people worldwide, triggered the race to understand in detail the molecular mechanisms of this disease. In this work, the differences of interactions between the SARS-CoV/SARS-CoV-2 Receptor binding domain (RBD) and the human Angiotensin Converting Enzyme 2 (ACE2) receptor were studied using in silico tools. Our results show that SARS-CoV-2 RBD is more stable and forms more interactions with ACE2 than SARS-CoV.

Screening and collective effects in randomly pinned fluids: a new theoretical framework.

We propose a theoretical framework for the dynamics of bulk isotropic hard-sphere systems in the presence of randomly pinned particles and apply this theory to supercooled water to validate it. Structural relaxation is mainly governed by local and non-local activated process. As the pinned fraction grows, a local caging constraint becomes stronger and the long range collective aspect of relaxation is screened by immobile obstacles.

Approaching Polymer Dynamics Combining Artificial Neural Networks and Elastically Collective Nonlinear Langevin Equation.

The analysis of structural relaxation dynamics of polymers gives an insight into their mechanical properties, whose characterization is used to qualify a given material for its practical scope. The dynamics are usually expressed in terms of the temperature dependence of the relaxation time, which is only available through time-consuming experimental processes following polymer synthesis. However, it would be advantageous to estimate their dynamics before synthesizing them when designing new materials.

Confinement Effects on the Spatially Inhomogeneous Dynamics in Metallic Glass Films.

This work develops the elastically collective nonlinear Langevin equation theory to investigate, for the first time, the glassy dynamics in capped metallic glass thin films. Finite-size effects on the spatial gradient of structural relaxation time and glass transition temperature () are calculated at different temperatures and vitrification criteria. Molecular dynamics is significantly slowed down near rough solid surfaces, and the dynamics at location far from the interfaces is sped up.

Theoretical insights into non-Arrhenius behaviors of thermal vacancies in anharmonic crystals.

Vacancies are prevalent point defects in crystals, but their thermal responses are elusive. Herein, we formulate a simple theoretical model to shed light on the vacancy evolution during heating. Vibrational excitations are thoroughly investigated moment recurrence techniques in quantum statistical mechanics.

Effects of surface charge and environmental factors on the electrostatic interaction of fiber with virus-like particle: A case of coronavirus.

We propose a theoretical model to elucidate intermolecular electrostatic interactions between a virus and a substrate. Our model treats the virus as a homogeneous particle having surface charge and the polymer fiber of the respirator as a charged plane. Electric potentials surrounding the virus and fiber are influenced by the surface charge distribution of the virus.

Nature of dynamic gradients, glass formation, and collective effects in ultrathin freestanding films.

Molecular, polymeric, colloidal, and other classes of liquids can exhibit very large, spatially heterogeneous alterations of their dynamics and glass transition temperature when confined to nanoscale domains. Considerable progress has been made in understanding the related problem of near-interface relaxation and diffusion in thick films. However, the origin of "nanoconfinement effects" on the glassy dynamics of thin films, where gradients from different interfaces interact and genuine collective finite size effects may emerge, remains a longstanding open question.

Theory of Pressure-Induced Rejuvenation and Strain Hardening in Metallic Glasses.

We theoretically investigate high-pressure effects on the atomic dynamics of metallic glasses. The theory predicts compression-induced rejuvenation and the resulting strain hardening that have been recently observed in metallic glasses. Structural relaxation under pressure is mainly governed by local cage dynamics.

Cooperative nanoparticle self-assembly and photothermal heating in a flexible plasmonic metamaterial.

We theoretically investigate equilibrium behaviors and photothermal effects of a flexible plasmonic metamaterial composed of aramid nanofibers and gold nanoparticles. The fiber matrix is considered as an external field to reconfigure a nanoparticle assembly. We find that the heating process tunes particle-particle and fiber-particle interactions, which alter adsorption of nanoparticles on fiber surfaces or clustering in pore spaces.

Determination of Young's Modulus of Active Pharmaceutical Ingredients by Relaxation Dynamics at Elevated Pressures.

A new approach is theoretically proposed to study the glass transition of active pharmaceutical ingredients and a glass-forming anisotropic molecular liquid at high pressures. We describe amorphous materials as a fluid of hard spheres. Effects of nearest neighbor interactions and cooperative motions of particles on glassy dynamics are quantified through a local and collective elastic barrier calculated using the elastically collective nonlinear Langevin equation theory.

Coupling between structural relaxation and diffusion in glass-forming liquids under pressure variation.

We theoretically investigate structural relaxation and activated diffusion of glass-forming liquids at different pressures using both Elastically Collective Nonlinear Langevin Equation (ECNLE) theory and molecular dynamics (MD) simulations. An external pressure restricts local motions of a single molecule within its cage and triggers slowing down of cooperative mobility. While the ECNLE theory and simulations generally predict a monotonic increase of the glass transition temperature and dynamic fragility with pressure, the simulations indicate a decrease of fragility as pressures above 1000 bar.

Applications of Mesoporous Silica-Encapsulated Gold Nanorods Loaded Doxorubicin in Chemo-photothermal Therapy.

We investigate the chemo-photothermal effects of gold nanorods (GNRs) coated using mesoporous silica (mSiO) loading doxorubicin (DOX). When the mesoporous silica layer is embedded by doxorubicin drugs, a significant change in absorption spectra enables to quantify the drug loading. We carried out photothermal experiments on saline and livers of mice having GNRs@mSiO and GNRs@mSiO-DOX.

Enhanced solar photothermal effect of PANi fabrics with plasmonic nanostructures.

The photothermal energy conversion in hanging and floating polyaniline (PANi)-cotton fabrics is investigated using a model based on the heat diffusion equation. Perfect absorption and anti-reflection of wet hanging PANi-cotton fabrics cause quick transfer of total incident light into water confining nearly 100% of the sunlight. As a result, a hanging membrane is found to have more attractive properties than a floating above water fabric.

Theoretical and Experimental Study of Compression Effects on Structural Relaxation of Glass-Forming Liquids.

We develop the elastically collective nonlinear Langevin equation theory of bulk relaxation of glass-forming liquids to investigate molecular mobility under compression conditions. The applied pressure restricts more molecular motion and therefore significantly slows down the molecular dynamics when increasing the pressure. We quantitatively determine the temperature and pressure dependence of the structural relaxation time.

Theory of Spatial Gradients of Relaxation, Vitrification Temperature and Fragility of Glass-Forming Polymer Liquids Near Solid Substrates.

We employ a new force-level statistical mechanical theory to predict spatial gradients of the structural relaxation time and of polymer liquids near microscopically rough and smooth hard surfaces and contrast the results with vapor interface systems. Repulsive rough (smooth) surfaces induce large slowing down (modest speeding up) of the relaxation time compared to the bulk. Nevertheless, a remarkable degree of universality of distinctive dynamical behaviors is predicted for different polymer chemistries and all interfaces, including a double exponential form of the alpha time gradient, power law decoupling of the relaxation time from its bulk value with exponential spatial variation of the exponent, exponential spatial gradient of , weak dependence of normalized gradients on vitrification criterion, and near linear growth with cooling of the slowed down layer thickness near a rough hard interface.

Theory of Structural and Secondary Relaxation in Amorphous Drugs under Compression.

Compression effects on alpha and beta relaxation process of amorphous drugs are theoretically investigated by developing the elastically collective nonlinear Langevin equation theory. We describe the structural relaxation as a coupling between local and nonlocal activated process. Meanwhile, the secondary beta process is mainly governed by the nearest-neighbor interactions of a molecule.

Effects of cooling rate on structural relaxation in amorphous drugs: elastically collective nonlinear langevin equation theory and machine learning study.

Theoretical approaches are formulated to investigate the molecular mobility under various cooling rates of amorphous drugs. We describe the structural relaxation of a tagged molecule as a coupled process of cage-scale dynamics and collective molecular rearrangement beyond the first coordination shell. The coupling between local and non-local dynamics behaves distinctly in different substances.

Confinement effects on the solar thermal heating process of TiN nanoparticle solutions.

We propose a theoretical approach to describe quantitatively the heating process in aqueous solutions of dispersed TiN nanoparticles under solar illumination. The temperature gradients of the solution with different concentrations of the TiN nanoparticles are calculated when confinement effects of the container on the solar absorption are taken into account. We find that the average penetration of solar radiation into the solution is significantly reduced upon increasing the nanoparticle concentration.

Theoretical Model for the Structural Relaxation Time in Coamorphous Drugs.

We propose a simple approach to investigate the structural relaxation time and glass transition of amorphous drugs. Amorphous materials are modeled as a set of equal sized hard spheres. The structural relaxation time over many decades in hard-sphere fluids is theoretically calculated using the elastically collective nonlinear Langevin equation theory associated with Kramer's theory.

Theory of the spatial transfer of interface-nucleated changes of dynamical constraints and its consequences in glass-forming films.

We formulate a new theory for how caging constraints in glass-forming liquids at a surface or interface are modified and then spatially transferred, in a layer-by-layer bootstrapped manner, into the film interior in the context of the dynamic free energy concept of the Nonlinear Langevin Equation (NLE) theory approach. The dynamic free energy at any mean location (cage center) involves contributions from two adjacent layers where confining forces are not the same. At the most fundamental level of the theory, the caging component of the dynamic free energy varies essentially exponentially with distance from the interface, saturating deep enough into the film with a correlation length of modest size and weak sensitivity to the thermodynamic state.

Elastically Collective Nonlinear Langevin Equation Theory of Glass-Forming Liquids: Transient Localization, Thermodynamic Mapping, and Cooperativity.

We analyze multiple new issues concerning activated relaxation in glassy hard sphere fluids and molecular and polymer liquids based on the elastically collective nonlinear Langevin equation (ECNLE) theory. By invoking a high-temperature reference state, a near universality of the apparent dynamic localization length scale is predicted for liquids of widely varying fragility, a result that is relevant to recent simulation studies and quasi-elastic neutron-scattering measurements. In contrast, in the same format, a strongly nonuniversal behavior is found for the activation barrier that controls long-time relaxation.

Theory of activated glassy dynamics in randomly pinned fluids.

We generalize the force-level, microscopic, Nonlinear Langevin Equation (NLE) theory and its elastically collective generalization [elastically collective nonlinear Langevin equation (ECNLE) theory] of activated dynamics in bulk spherical particle liquids to address the influence of random particle pinning on structural relaxation. The simplest neutral confinement model is analyzed for hard spheres where there is no change of the equilibrium pair structure upon particle pinning. As the pinned fraction grows, cage scale dynamical constraints are intensified in a manner that increases with density.