Molecular dynamics simulations have been performed to study the effects of cross-link density and distribution on network topology, dynamic structural properties, tensile mechanical viscoelastic properties chemically cross-linked polymers. Simulation results show that introduction cross-links slows chain down thus leads a slight increase in glass transition temperature. Improving dispersion state is found be essentially equivalent increasing effective density, as reflected topological...

Conventional polymers of nonfluorescent monomers show strong fluorescence without incorporating any fluorescent agent. The intensity photoluminescence these is similar to that emitted by conventional fluorophore-containing polymers. This finding offers a simple yet versatile platform prepare using molecules.

In contrast to the stable dinitrogen molecule, white phosphorus (P4) and yellow arsenic (As4) are very reactive allotropic modifications of these two heavier pnictogen elements, which has greatly hampered study their properties applications. Thus, safe storage transport them is imperative. Supramolecular caged structures one most efficient approaches for encapsulation stabilization species; however, use in P4 As4 chemistry rare. current work, we demonstrate a new design strategy constructing...

Photocatalytic C-C bond formation coupled with H2 production provides a sustainable approach to producing carbon-chain-prolonged chemicals and hydrogen energy. However, the involved radical intermediates open-shell electronic structures are highly reactive, experiencing predominant oxidative or reductive side reactions in semiconductors. Herein, we demonstrate that bonding on catalyst surface bulk solution can inhibit oxidation reverse reaction of α-hydroxyethyl radicals (αHRs)...

Probiotics are indispensable for maintaining the structure of gut microbiota and promoting human health, yet their survivability is frequently compromised by environmental stressors such as temperature fluctuations, pH variations, mechanical agitation. In response to these challenges, microfluidic technology emerges a promising avenue. This comprehensive review delves into utilization encapsulation delivery probiotics within gastrointestinal tract, with focus on mitigating obstacles...

Supported noble metal nanoclusters and single-metal-site catalysts are inclined to aggregate into particles, driven by the high surface-to-volume ratio. Herein, we report a general method atomically disperse nanoparticles. The activated carbon supported nanoparticles of Ru, Rh, Pd, Ag, Ir Pt metals with loading up 5 wt. % completely dispersed reacting CH3I CO mixture. dispersive process Rh nanoparticle is investigated in depth as an example. in-situ detected I• radicals molecules identified...

Water oxidation is a linchpin in solar fuels formation, and catalysis by single-site ruthenium complexes has generated significant interest this area. Combining several theoretical tools, we have studied the entire catalytic cycle of water for catalyst starting with [Ru II (tpy)(bpm)(OH 2 )] 2+ (i.e., -OH ] ; tpy 2,2 ′ ∶6 ,2 ′′ -terpyridine bpm 2,2′-bypyrimidine) as representative example new class catalysts. The redox potentials p K calculations first two proton-coupled electron transfers...

Heterogeneous single-metal-site catalysts have been drawing increasing interests in the field of academy and industry because comparable catalytic activity with homogeneous catalyst easy separation. Here, an efficiently heterogeneous single-site Rh on activated carbon (Rh1/AC) was constructed, which performs three times than corresponding for methanol carbonylation. Experimental data reveals that apparent activation energy Rh1/AC is 0.91 eV, far less 1.54 eV its counterpart. Ex situ EXAFS...

Ab initio constrained molecular dynamics and metadynamics were employed to investigate the mechanism of proton transfer in guanine-cytosine (GC) adenine-thymine (AT) base pairs gas phase at room temperature. It is shown that double (DPT) GC pair a concerted asynchronous mechanism, three pathways with similar free energy barrier start from canonical end up its “rare” imino-enol tautomer. The activation for route DPT starts hydrogen atom movement O6(G)-N4(C) bridge approximately 1.0 kcal/mol...

An understanding of the structure–property relationship in polymer/nanorod (NR) nanocomposites is fundamental importance designing and fabricating polymer (PNCs) with desired properties. Here, we study structural, mechanical, viscoelastic properties polymer-grafted NR filled PNCs, using coarse-grained molecular dynamics simulation. The mechanical reinforcement efficiency found to be determined by NR/polymer interfacial properties, which are turn modulated grafting density, grafted chain...

To enhance the catalytic performance of single-metal-site catalysts (SMSCs), regulating interaction between active site and substrate is crucial but challenging. Herein, a series Rh-based SMSCs (Rh/m-3vPAr3-POLs) were designed synthesized on P-abundant porous organic polymers (POPs) with different electronegativities frame phosphine. The Rh–P sites various POPs modified by functional groups (−F, −H, −Me, or −OMe). Both formation HRh(CO)2(P)2 species insertion CO promoted via...

Through coarse-grained molecular dynamics simulations, the effects of nanoparticle properties, polymer-nanoparticle interactions, chain crosslinks and temperature on stress-strain behavior mechanical reinforcement polymer nanocomposites (PNCs) are comprehensively investigated. By regulating filler-polymer interaction (miscibility) in a wide range, an optimal dispersion state nanoparticles is found at moderate strength, while properties PNCs improved monotonically with increase...

Using the off-lattice Monte Carlo simulation and replica-exchange method, we studied behavior of nongrafted homopolymer adsorption by an attractive substrate from both canonical microcanonical views. An transition is identified peak in specific heat compared with conventional polymer one end anchored on surface substrate. Judging typical “backbending effect” negative ensemble, first-order-like when relatively strong. However, it becomes second-order-like strength weak enough. Further study...

Abstract As the rising renewable energy demands and lithium scarcity, developing high‐capacity anode materials to improve density of potassium‐based batteries (PBBs) is increasingly crucial. In this work, a unique orderly multilayered growth (OMLG) mechanism on 2D‐Ca 2 Si monolayer theoretically demonstrated for potassium storage by first‐principles calculations. The global‐energy‐minimum Ca semiconductor with isotropic mechanical properties remarkable electrochemical properties, such as low...

Using the replica-exchange multicanonical Monte Carlo simulation, intra-association of hydrophobic segments in a heteropolymer was numerically investigated by microcanonical analysis method. We demonstrated that entropy shows features one or multiple convexes association transition region depending on number and distribution chain. found negative specific heats imply first-order-like with coexistence phases.

Using replica-exchange multicanonical Monte Carlo simulation, the aggregates of two homopolymers were numerically investigated through microcanonical analysis method. The entropy showed one convex function in transition region, leading to a negative specific heat. origin temperature backbending was rearrangement segments during process aggregation; this aggregation proceeded via nucleation and growth mechanism. It observed that with sequence number from 10 13 polymer chain have effects on...

The adsorption process of a homopolymer chain nongrafted on an attractive surface is numerically investigated using replica-exchange multicanonical Monte Carlo simulation. Based the microcanonical analysis, entropy in transition shows convex features. Correspondingly, with coexistence two phases, negative specific heat also observed region, implying first-orderlike transition. origin due to nonextensitivity energy system. This has some similarities nucleation and growth mechanism crystalline...

Laser welding is widely used for the joining of aluminum alloy in automotive industry, and vehicles produced are inevitably subjected to high strain rate loading during their service. Therefore, this paper studied mechanical properties 6061-T6 its laser welded joint at rates between 0.0003 1000 s−1. Results showed that microstructure material (WM) was much finer than base (BM), typical columnar crystals grew perpendicularly fusion line, minimum hardness value (~56 HV) obtained inside WM. The...

Density-functional theory calculations are carried out for a biomimetic dimanganese complex, [H2O(terpy)MnIII(μ-O)2MnIV(terpy)OH2]3+(1, terpy = 2,2′:6′,2″-terpyridine), which is structural model the oxygen evolving center of photosystem II. Theoretical investigations aim at elucidating asymmetry features in geometric and electronic structures complex 1, as well their influences on chemical functions two manganese centers, presence water solvent. With insight gained from first-principles...

Abstract Nitrogen‐doped porous carbon (NPC) materials have attracted increased attention for zinc‐air battery (ZAB) applications because of their comparable electrocatalytic activity to precious metals. However, few metal‐free NPC catalysts exhibit an oxygen reduction reaction performance better than Pt catalysts, together with high evolution catalytic activity. Herein, efficient electrocatalyst based on highly integrated nanofiber (CNF) and aerogels, CNF as the core shell, is demonstrated....