Search Results (2,064)

To enhance the gelling functionality of plant proteins, this study developed hybrid gels by blending casein with soy protein isolate (SPI) at various ratios using microbial transglutaminase (MTG) as a cross-linking catalyst. The gels were systematically characterized in terms of microstructure, water distribution, rheological and textural properties, secondary structure, and intermolecular interactions. Incorporation of casein significantly improved gel strength, water-holding capacity, and network uniformity. Notably, the 1:1 casein-to-SPI ratio yielded the highest performance, featuring extensive inter-protein cross-linking, an increased proportion of ordered secondary structures, and a finely porous matrix that effectively immobilized water. Mechanistically, MTG-catalyzed covalent bonding established the primary network scaffold, while hydrophobic interactions and disulfide bonds further stabilized the gel matrix. These findings demonstrate that MTG-induced Casein–SPI hybrid gels can enhance the functional properties of plant proteins and offer a viable strategy for designing sustainable protein-based food structures with tailored performance. Full article

We present a modular building block strategy for synthesizing phosphonated polyaromatic systems as an alternative to the conventional late-stage phosphonation of prefabricated aromatic scaffolds, which often requires harsh conditions and has limited tolerance for functional groups. A monophosphonated biphenyl building block was obtained via nickel-catalyzed phosphonation of dibromobiphenyl at 170 °C for three hours. This synthesis is more economical and milder than typical high-temperature palladium systems. In parallel, a borated pyrene derivative was prepared by Suzuki–Miyaura borylation. The final palladium-catalyzed Suzuki cross-coupling reaction produced the target compound, octaethyl(pyrene-tetrakis(biphenyl))tetrakis(phosphonate), Et₈-PyTPPE. Single-crystal X-ray diffraction reveals a centrosymmetric molecule that crystallizes in the triclinic space group P–1, with the inversion center located at the central C–C bond of the pyrene core. The pyrene unit is essentially planar, while the biphenylphosphonate arms are highly twisted relative to the core and to each other. The crystal packing is dominated by weak intermolecular interactions, and no significant π–π stacking is observed. Hirshfeld surface analysis shows that H···H (60.5%) and C···H (22.5%) contacts predominate, while O···H interactions (14.4%) with phosphoryl oxygen atoms represent the most relevant directed contacts. From photophysical investigations, Et₈-PyTPPE exhibits blue fluorescence (λ_em. = 452 nm) in solution and aggregation-induced red-shifted emission with nanosecond lifetimes in the solid state, confirming purely fluorescent behavior. Full article

This study aimed to elucidate the mechanisms by which Tremella fuciformis powder (TFP) improves the gel properties of soy yogurt by investigating the effects of TFP particle size on physicochemical properties and rheological behavior, combined with microstructural characterization and intermolecular interaction analyses. The results demonstrated that reducing TFP particle size (from 432.33 µm to 50.10 µm) significantly enhanced its hydration properties and increased the water holding capacity of soy yogurt to 99.44% (p < 0.05). Rheological analysis showed that reduced TFP particle size increased the apparent viscosity, storage modulus, and loss modulus of soy yogurt, consistent with the formation of a denser gel network observed via particle size analysis and SEM. While larger particles disrupted ordered protein cross-linking, smaller TFP particles enhanced soy yogurt gel properties by filling voids, during which volumetric expansion through water absorption reinforced gel matrix continuity. Zeta potential and intermolecular interaction analyses suggested that reduced TFP particle size enhanced non-covalent interactions in soy yogurt. These results indicate that TFP improves the gel properties of soy yogurt primarily through filler effects and protein interactions, providing a valuable reference for formulating stable plant-based yogurt products. Full article

Asphalt rheological properties are fundamental to pavement performance, yet their accurate assessment requires multi-scale characterization due to asphalt’s inherent complexity. This article reviews the connections between asphalt rheology across chemical, microstructural, and macro-mechanical scales, employing a methodological analysis of supramolecular and colloidal models for micro-scale behavior and dynamic shear rheometry for macro-scale properties. Current research confirms asphalt as a complex multiphase continuum, where micro-scale rheology is explained by intermolecular interactions and colloidal structures, while macro-scale analysis successfully characterizes linear viscoelasticity through established empirical and mechanical models. However, the study identifies critical gaps: nonlinear viscoelastic characterization under large-amplitude oscillatory shear (LAOS) remains underdeveloped, and fundamental issues like directly probing molecular interactions and the origin of microstructures like the “bee structure” are unresolved. The primary conclusion is that a comprehensive understanding of asphalt rheology hinges on future research that integrates experimental and simulation data across these scales to bridge the gaps between chemical composition, microstructure, and macroscopic performance. Full article

Oily substances (oils, greases, lubricants, etc.) are among the most persistent pollutants for water. They mix with water to form emulsions that contaminate large volumes. Therefore, this project evaluated the use of porous systems (polyurethane foam) modified with polydimethylsiloxane-modified silica (SiO₂/DMS) hybrid ceramics as filtration membranes at the laboratory scale for vegetable oil. The polyurethane foam was modified using sol solutions with various SiO₂/PDMS ratios obtained via the sol–gel method. Tetraethyl-orthosilicate (TEOS) was used as the silica precursor. Three different polydimethylsiloxane chains were employed as the organic fragment: polydimethylsiloxane hydroxyl terminated (DMS-CH₃), aminopropyl-terminated polydimethylsiloxane (DMS-N), and copolymer polydiphenylsiloxane-polydimethylsiloxane hydroxyl terminated (PDS). The siloxane chain was added at a concentration of 20–40% w/w. The modification of the porous system was determined using different characterization techniques, including infrared spectroscopy, which was used to observe the main functional groups. Optical microscopy and SEM were used to identify the hybrid ceramic deposited into the pore structure of the polyurethane sponge. Contact angle measurements revealed the hydrophobic character of the modified material. The removal capacity was evaluated by using vegetable oil as a representative oily contaminant, with values ranging from 43.42 to 96.78 g of oil per gram of adsorbent. In the case of gasoline, removal capacities between 27 and 54 g were observed. This study demonstrated the influence of hydrophobicity on vegetable oil removal, confirming that higher hydrophobicity leads to greater adsorption capacity. Nevertheless, the use of a viscous contaminant introduced challenges in the extraction process from the PS/SiO₂-DMS system. Despite this limitation, the material maintained adequate removal performance for up to five reuse cycles. On the other hand, the removal capacity depends on the amount of polysiloxane chain in the ceramic, as well as the functional group, exhibiting the following behavior: DMS-N < DMS-CH₃ < PDS. This study demonstrates that hydrophobicity is a key property for enhancing the removal capacity of oily substances. Moreover, the control of intermolecular interactions further strengthens this effect, as evidenced in the PS/SiO₂–PDS system. Full article

The effect of LiPF₆ acidity, represented by LiPF₆·xHF adduct formation and its interaction with fluoride species, on the surface reactivity and stability of LiPF₆ was investigated using density functional theory (DFT) calculations performed with the Vienna Ab initio Simulation Package (VASP). The exchange–correlation energy was described using the Perdew–Burke–Ernzerhof (PBE) functional within the Generalized Gradient Approximation (GGA). Four distinct surface terminations of the (003) and (101) facets—F4–P2–Li, P2–F3–Li, Li2–F3–P, and F4–Li2–P were systematically examined. Surface and adsorption energies were evaluated together with key electronic descriptors, including the work function, dipole moment, electron localization function (ELF), electrostatic potential, band structure, and density of states, to elucidate the mechanisms governing adsorption and stability. The (101) facet exhibits a pronounced susceptibility to HF-induced solvation, driven by enhanced surface polarity, a low work function, and intermolecular H–F interactions at lithium-exposed terminations. In contrast, the thermodynamically dominant (003) facet shows greater resistance to HF interaction, with adsorption remaining predominantly molecular and progressing toward deliquescence only at elevated HF concentrations. Fluorine-rich and charge-balanced terminations on both facets display enhanced stability, characterized by high work functions, minimal ELF redistribution, and suppressed charge transfer. Full article

Phenothiazine is a heteroaromatic molecule capable of various noncovalent interactions, including halogen bonding and π-stacked association. Despite its broad use in functional materials and pharmaceutical ingredients, a systematic comparison of these interaction modes has been lacking. Here, we report a combined experimental and computational study of intermolecular interactions of phenothiazine with a prototypical halogen-bond (HaB) donor (tetrabromomethane), planar π-electron acceptors (tetracyanopyrazine and tetrafluoro-p-benzoquinone), and multifunctional species capable of both interaction types (iodo- and bromo-3,5-dinitrobenzenes). X-ray structural analysis revealed that CBr₄ forms exclusively C–Br···π halogen bonds with the aromatic rings of phenothiazine, whereas all π-acceptors yield alternating donor–acceptor stacks characterized by multiple short contacts indicative of multicenter interactions. Notably, co-crystals of iodo- and bromodinitrobenzenes with phenothiazine display only π-stacked architectures. Density-functional calculations showed that isolated HaB complexes involving N, S, or π sites of phenothiazine possess comparable binding energies (≈−3 kcal mol⁻¹), whereas π-stacked complexes are substantially stronger (≈−9–12 kcal mol⁻¹). QTAIM, NCI, NBO, and energy-decomposition analyses indicated that while amounts of charge transfer in halogen-bonded and π-stacked complexes are comparable, the enhanced stability of the latter originates primarily from a large dispersion contribution. These results rationalize the solid-state preference for π-stacking over halogen bonding in systems where both motifs are accessible and clarify the hierarchy and physical origin of noncovalent interactions involving phenothiazine, providing guidance for the design of supramolecular assemblies and functional materials based on this versatile electron donor. Full article

Cellulose nanocrystals (CNCs) possess outstanding mechanical properties and sustainability; however, their hydrophilic nature makes their dispersion challenging in hydrophobic bioplastic matrices. Surface modification of CNC is therefore inevitable for effective nanocomposite fabrication. In this study, CNC surface was modified using a green, water-based grafting-from method, enabling the growth of poly(2-hydroxyethyl methacrylate) (PHEMA) chains directly from its surface. This modification decreases intermolecular hydrogen bonding among CNCs and enhances their compatibility with poly(butylene adipate-co-terephthalate) (PBAT), a commercially available biodegradable aliphatic–aromatic copolyester widely used in sustainable packaging applications. The enhanced interfacial interaction arises from both the improved dispersion of CNCs within the PBAT matrix and the ability of PHEMA’s hydroxyl groups to form secondary interactions with PBAT. To examine how grafted polymer chain length influences CNC dispersion, PHEMA was grown from CNC surfaces at different grafting degrees. Additionally, PHEMA homopolymers were synthesized and melt-mixed with PBAT to evaluate the role of PHEMA in the absence of CNC. Neat and modified CNCs (mCNCs) were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, water contact angle measurements, wettability tests, and thermogravimetric analysis. Nanocomposites containing 3 wt% neat CNCs, mCNCs, or PHEMA homopolymers were subsequently prepared using an internal melt mixer. Melt rheology, differential scanning calorimetry, and dynamic mechanical analysis were then used to characterize the final viscoelastic and thermomechanical behavior of the resulting nanocomposites. The increased storage modulus and complex viscosity of the nanocomposites confirmed that the CNCs grafted with an intermediate PHEMA chain length exhibited improved network formation and enhanced interfacial interaction with PBAT. Full article

A comprehensive MD + QC methodology was developed and applied to evaluate various aspects of Arbidol interactions with functional amino acids of surface proteins of influenza virus and SARS-CoV-2. The spatial structure, solvation features, conformational behavior of Arb AA (AA–Trp, Tyr, Phe, and Val) complexes were established, and the statistics of intermolecular interactions in the complex were described. It was found that Arb can participate in strong and long-lived π-π stacking interactions with aromatic amino acids. The binding energy (BE) of Arbidol and amino acids in aqueous solution was estimated using an explicit solvation model, QTAIM analysis and correlation of BE vs. total electron density at the bond critical points of the complex. Theoretical calculations were validated by experimental studies of fluorescence (FL) quenching of aromatic AA by Arbidol. Spectral-fluorescent properties of Arbidol hydrochloride in aqueous solutions were studied, and the luminescence quantum yield for the electronically excited state of Arb was determined. Full article

In bulk heterojunction (BHJ) organic solar cells (OSCs) employing perylene diimide (PDI)-based non-fullerene acceptors, excessive intermolecular interactions among PDI units lead to severe aggregation and pronounced donor–acceptor phase separation, both of which critically limit device performance. To address these issues, numerous structurally engineered PDI derivatives have been developed. In particular, twisted multi-PDI architectures designed to suppress intermolecular aggregation have shown improved morphological control; however, such twisted structures are often highly amorphous, which reduces electron-transport efficiency and constrains OSC performance. In this work, we introduce a mixed-acceptor strategy combining a twisted PDI dimer (SF-PDI₂) with a planar monomeric PDI (m-PDI) to balance aggregation and morphological uniformity. Ternary blend OSCs consisting of PTB7-Th as the donor and these two PDI acceptors exhibit systematic performance variations depending on their relative ratios. At the optimized composition (SF-PDI₂:m-PDI = 90:10 by weight), the device outperforms single-acceptor systems, which is attributed to controlled aggregation arising from the complementary structural features of the two PDI acceptors. This study demonstrates that combining mixed PDI acceptors with similar molecular moieties enables precise control of aggregation, improving both morphology and photovoltaic performance. Full article

The impact modification of polyamide 6 (PA6) using maleic anhydride-grafted ethylene/1-octene copolymers (EOR-g-MAH) involves a trade-off between improved compatibilization, grafting-induced changes in modifier molecular weight $MW$, and melt processability. In this study, EOR modifiers with comparable initial $MW$ but different octene contents ($c_{\mathrm{o}\mathrm{c}\mathrm{t}}$ = 13, 15, and 16 mol%) were grafted to two MAH levels ($c_{\mathrm{M}\mathrm{A}\mathrm{H}}$ = 0.5 and 1.0 wt%) and incorporated into PA6 at a fixed composition. The system was designed to maintain a comparable microstructure, enabling the isolation of grafting-induced changes in modifier properties from microstructural effects. $MW$ distributions were analyzed by gel permeation chromatography, and the impact behavior was evaluated over a wide temperature range, using an instrumented Charpy impact test. The results reveal a strong, interrelated, $c_{\mathrm{o}\mathrm{c}\mathrm{t}}$- and $c_{\mathrm{M}\mathrm{A}\mathrm{H}}$-dependent competition between β-scission and cross-linking during grafting, which governs the modifier’s $MW$ distribution and particle strength. Higher $c_{\mathrm{o}\mathrm{c}\mathrm{t}}$ (15 and 16 mol%) enhances the impact performance up to ≈0 °C, well above the brittle–ductile transition temperature (BDTT), through increased elastic and plastic deformation capability of the modifiers. At elevated temperatures, however, successive melting of the modifiers leads to a loss of particle strength. At high $c_{\mathrm{o}\mathrm{c}\mathrm{t}}$ and $c_{\mathrm{M}\mathrm{A}\mathrm{H}}$ = 1.0 wt%, susceptibility to β-scission increases, leading to $MW$ reduction that, for $c_{\mathrm{o}\mathrm{c}\mathrm{t}}$ = 16 mol%, is detrimental to impact performance, particularly above the BDTT. This effect is further amplified by reduced ductility due to stronger polar intermolecular interactions at high grafting levels. A moderate $c_{\mathrm{M}\mathrm{A}\mathrm{H}}$ = 0.5 wt% and $c_{\mathrm{o}\mathrm{c}\mathrm{t}}$ = 15 mol% provides an optimal compromise between strength and ductility, delivering high impact strength across a broad temperature range. At this $c_{\mathrm{M}\mathrm{A}\mathrm{H}}$ level, the number of PA6 chains covalently anchored to the modifier particles is moderate, resulting in lower compound viscosity and supporting favorable melt processability. Full article

Ammonium dinitramide (ADN), a new-generation green high-energy oxidizer, faces application challenges due to its strong hygroscopicity and poor compatibility with polymer binders. This study proposes a double-shell structure with ADN as the core, graphene oxide (GO) as the intermediate layer, and a binder as the outer shell. Molecular dynamics simulations were performed to investigate composite systems using nitrocellulose (NC), cellulose acetate butyrate (CAB), polystyrene (PS), and their blends NC/CAB and NC/PS as binders. The results demonstrate that GO acts as a “molecular double-sided adhesive”, significantly enhancing the interfacial interaction between ADN and the binders. The NC/PS blend binder exhibits the best overall performance, with the binding energy increased by 1.13 times. Analysis revealed that the NC/PS system establishes the strongest intermolecular interactions among ADN, GO, and the binder via mechanisms like π-π stacking and multiple hydrogen bonds. The glass transition temperature reaches 400.93 K, indicating excellent thermal stability and potential safety/reliability. Mechanical property analysis shows that the NC/PS composite system imparts a better comprehensive balance of stiffness, shear performance, and structural isotropy to the ADN-based polymer-bonded explosive (PBX). This research elucidates the enhancement mechanism of GO and the regulation principles of binders at the molecular scale, providing a theoretical foundation for designing high-performance energetic material. Full article

Concentrated solutions of polycarbosilane (PCS) are critically important for the development of continuous SiC precursor fibers, where solvent–polymer interactions govern rheology, viscoelastic stability, and spinnability. In this work, PCS solutions in two nonpolar hydrocarbon solvents with different molecular architectures as linear n-heptadecane and bicyclic decalin were systematically investigated over a wide concentration range, with emphasis on the semi-dilute entangled and concentrated regimes relevant to solution-based fiber spinning. A combined experimental approach involving steady and oscillatory rheometry and Fourier transform infrared (FTIR) spectroscopy was used to elucidate the influence of solvent structure on solvation, viscoelastic response, microstructural organization, and local intermolecular interactions. Despite similar dilute-solution interaction parameters, the concentrated regimes exhibit pronounced solvent-dependent differences in elasticity and flow behavior. For the first time, linear heptadecane is identified as a viable and technologically promising solvent for PCS, enabling the formation of thermostable homogeneous concentrated solutions with enhanced deformability. This behavior opens a realistic pathway toward a new solution-based fiber-spinning route based on elasticity-controlled processing. The results demonstrate that solvent molecular geometry governs the structure–rheology–processability relationship of concentrated PCS systems rather than solubility parameters alone, providing a new framework for solvent selection in SiC precursor fiber technologies. Full article

Carbon fiber-reinforced resin matrix composites (CFRC) are extensively used in aerospace, automotive manufacturing, and sports equipment. However, the brittle nature of the resin matrix causes CFRC to exhibit severe vibrations and noise under dry friction conditions. Enhancing the intrinsic damping properties of the resin matrix serves as a fundamental and effective strategy to mitigate vibration and noise radiation in composite components. This study systematically investigates high-temperature co-curing damping composites using co-curing technology, aiming to improve the mechanical performance and damping characteristics of traditional fiber-reinforced epoxy resin composites. A novel carbon fiber-reinforced terminal carboxyl nitrile epoxy pre-polymer composite material demonstrates both stable chemical properties and excellent high-temperature resistance. Through formulation adjustments, the curing temperature and time of epoxy resin are matched with those of the terminal carboxyl nitrile epoxy pre-polymer. The performance of epoxy carbon fiber composites was evaluated through tensile tests, flexural tests, impact tests, infrared spectroscopy, thermogravimetric analysis, dynamic mechanical analysis, scanning electron microscopy, and X-ray diffraction. Results show that blending epoxy resin with terminal carboxyl nitrile liquid rubber enhances energy dissipation by increasing intermolecular friction and hydrogen bonding interactions. The damping ratio of epoxy resin-based carbon fiber composites reaches as high as 1.67%. Tensile strength, flexural strength, and impact strength reach 1968 MPa, 1343 MPa, and 127 kJ/m², respectively. The addition of terminal carboxylated nitrile liquid rubber facilitates the formation of continuous friction membranes, enhancing friction stability. Tensile tests demonstrate that carbon fiber composites containing 25% terminal carboxylated nitrile liquid rubber outperforms other formulations. As evidenced by impact tests, the performance of the prepared composites is superior to that of other configurations. Dynamic mechanical analysis indicates that the 25% rubber-containing composites exhibit enhanced damping characteristics and higher loss modulus. Experimental results confirm that this study advances the development of functional composites for vibration reduction and noise control applications. Full article

Isoflavones are plant-derived polyphenols with broad biological activity; however, their application in topical formulations is limited by poor aqueous solubility. The aim of this study was to enhance the aqueous solubility of formononetin using a solvent-free hot-melt extrusion (HME) approach and to enable its incorporation into a hydrogel formulation suitable for skin delivery. Amorphous formononetin-based systems were prepared by HME using polymeric carriers and hydroxypropyl-β-cyclodextrin, with and without prior inclusion complex formation. The resulting formulations were characterized using XRPD, DSC, and FT-IR/ATR to assess amorphization and intermolecular interactions. Aqueous solubility and skin permeability were evaluated using solubility testing, PAMPA, and Franz diffusion cells. The optimized amorphous system exhibited a substantial increase in apparent aqueous solubility compared to crystalline formononetin while maintaining comparable permeability. Cyclodextrin–formononetin interactions were effectively generated during the extrusion process, rendering pre-inclusion unnecessary. The selected system was successfully incorporated into a hydrogel matrix. This study demonstrates that solvent-free HME combined with cyclodextrins is an effective strategy for improving formononetin solubility and enabling its application in hydrogel-based topical delivery systems. Full article