Search Results (8,647)

The food packaging sector widely relies on polymeric materials, and as sustainability concerns grow, commodity polymers need to be replaced with innovative and more sustainable materials. Thermoplastic polyurethane (TPU) is a versatile elastomeric polymer characterized by flexibility, strength, chemical and abrasion resistance, and biocompatibility. However, it presents some limitations, notably in terms of functional properties (such as barrier properties). The use of nano-sized renewable fillers, such as cellulose nanocrystals (CNCs), may improve these properties, extending the applicability range of TPU. In this work, bio-based TPU nanocomposites were obtained by adding commercial silane-modified cellulose nanocrystals (Si−O−CNC) at different contents (1–5 wt.%). The nanocomposites were produced via melt mixing followed by compression molding and were characterized in terms of their chemical (FTIR), morphological, thermal, mechanical, rheological, wettability, and barrier properties (i.e., water vapor permeability, WVP and oxygen transmission rate, OTR). The presence of Si−O−CNC promoted hydrogen-bonding interactions with the TPU matrix, affecting the microphase separation and organization of the hard segments. These microstructural changes improved thermal stability, reduced WVP and OTR, and increased tensile properties at lower nanofiller contents (1–3 wt.%). At higher contents, partial nanofiller aggregation was observed, leading to a reduction in mechanical performance. Overall, these results suggest that TPU/Si−O−CNC nanocomposites have promising potential as sustainable food packaging materials. Full article

The blood–brain barrier (BBB) represents a major challenge in central nervous system (CNS) drug development due to its selective permeability. Multiple molecular properties such as lipophilicity, molecular size, and hydrogen-bonding potential critically influence a compound’s ability to cross the BBB. In particular, the presence of hydrogen bond donors (HBDs) and the ability to form intramolecular hydrogen bonds (IMHBs) play a crucial role in modulating brain penetration. This review discusses the mechanistic impact of HBDs and IMHBs on BBB permeability, highlighting key physicochemical parameters and case studies that demonstrate the utility of IMHBs in CNS drug design. Strategies to mask polar functionalities through IMHB formation are emphasized as promising tools to optimize brain delivery without compromising pharmacological activities. The literature reviewed in this work was collected through comprehensive searches of scientific databases, including SciFinder, PubMed, Web of Science, and Scopus, complemented by manual search of reference lists from relevant publications. Full article

This article systematically reviews the structural characteristics of layered double hydroxides and biochar (LDHs/biochar) composites, summarizes the features and optimization strategies of preparation methods such as coprecipitation, hydrothermal synthesis, ball milling, and calcination–reconstruction, analyzes their adsorption performance and mechanisms in controlling various water pollutants including organic contaminants, heavy metals, and nutrients, and provides insights into future research trends and practical applications, aiming to offer references for improving material performance and promoting practical use. The existing research results show that LDHs/biochar composites exhibit good application potential for various pollutants, such as dyes, antibiotics, heavy metal ions, and phosphates. The coprecipitation method is simple and easy to operate, and the LDHs/biochar composites prepared by this method exhibit favorable adsorption performance, with potential for industrial-scale production. The mechanisms of pollutant removal by LDHs/biochar composites primarily include electrostatic attraction, ion exchange, hydrogen bonding, complexation, and π–π electron interactions. Both the biomass type and the LDH type influence the adsorption performance of the composites. Therefore, designing LDHs/biochar composites based on pollutant characteristics and adsorption mechanisms is key to achieving effective pollution control. Currently, research on target pollutant-oriented material design and material regeneration remains underdeveloped and requires further breakthroughs. Full article

Aronia melanocarpa puree is rich in anthocyanins and proanthocyanidins, but its pronounced tannin-derived astringency limits product acceptance. This study developed a non-removal astringency-modulation strategy using food-grade L-proline and evaluated its molecular basis, processing window, and quality effects. Ultraviolet–visible (UV–Vis) and Fourier-transform infrared (FT-IR) spectroscopic analyses suggested that L-proline altered the local microenvironment of procyanidin B2 (PC-B2) through hydrogen bonding, hydrophobic association, and molecular packing rearrangement, without evident disruption of the PC-B2 aromatic skeleton. In a PC-B2–bovine serum albumin model, an appropriate L-proline level reduced the protein precipitation rate from 45.3% to 31.2% and increased soluble phenolic retention, suggesting weakened polyphenol–protein precipitation. The strategy was then optimized in puree using machine learning-assisted multi-response analysis and Box–Behnken validation. The recommended condition was 150 mg/100 mL L-proline at 40 °C for 60 min, yielding a deastringency rate of 36.13%, with anthocyanin and vitamin C retention rates of 88.80% and 55.56%, respectively. The optimized treatment maintained red color, colloidal dispersion, and shear-thinning behavior; increased the anthocyanin digestion retention index from 50.0% to 87.4%; and improved overall sensory acceptance from 4.17 to 8.17. These findings support L-proline-mediated microenvironmental modulation as a mild processing approach for high-tannin cloudy berry products. Full article

The efficient capture of carbon dioxide (CO₂) using polymer, supported ionic liquids (ILs) remains challenging due to limited understanding of atomic-scale interaction mechanisms. Here, a polystyrene (PS) oligomer supported by an amidinium chloride-based IL is proposed as a CO₂-absorbing material. Density functional theory (DFT) calculations were employed to investigate the structural, electronic, and intermolecular interaction energy characteristics of the PS oligomer, amidinium chloride ILs, CO₂, and their binary and ternary complexes. Molecular electrostatic potential maps (MEPs), reduced density gradient (RDG) plots with non-covalent interaction (NCI) snapshots, quantum theory of atoms in molecules critical point (CP) analysis, and electron localization function (ELF) analysis reveal pronounced hydrogen bonding and dispersion interactions between PS and IL that modulate the electronic environment of the IL anion, which is the primary CO₂ binding site. Interaction energy calculations show that the ternary PS–IL–CO₂ complex exhibits a significantly enhanced binding energy compared to the isolated IL–CO₂ complex, providing quantitative evidence for the cooperative role of the PS support. The results indicate enhanced CO₂ binding in the presence of PS supported by ILs, driven by cooperative electrostatic and dispersion interactions. These findings provide molecular-level insights into CO₂ capture mechanisms in polymer–IL hybrid systems. Full article

NAD⁺ depletion is a defining feature of the aging cell, driven by a progressive decline in nicotinamide phosphoribosyltransferase (NAMPT) activity, the rate-limiting enzyme of the NAD⁺ salvage pathway. Pyrroloquinoline quinone (PQQ), a plant-derived redox-active quinone cofactor, elevates intracellular NAD⁺ by a mechanism that remains incompletely understood. We employed an integrated in silico approach combining molecular docking, density functional theory (DFT), and 100 ns molecular dynamics (MD) simulation to evaluate whether PQQ directly targets NAMPT. Docking against the NAMPT crystal structure (PDB: 7ENQ) yielded a binding free energy of −9.4 kcal/mol, with PQQ positioned in the allosteric activation site and forming hydrogen bonds at His191, Asp219, and Val242 together with π–π stacking at Tyr188, extending a known synthetic activator pharmacophore to a dietary ligand class. MM-GBSA analysis yielded binding free energy = −31.2 kcal/mol, confirming dominant electrostatic and van der Waals stabilization. In silico alanine mutagenesis of Tyr188 and Val242 reduced binding affinity to −7.2 and −7.0 kcal/mol respectively, with complete loss of allosteric-site contacts, validating the proposed mechanism computationally. DFT analysis revealed a HOMO–LUMO gap of 3.20 eV and electrophilicity index ω = 8.91 eV, consistent with non-covalent binding to nucleophilic residues. MD simulation confirmed retention of PQQ within the allosteric site over 100 ns. These data provide a structural and electronic framework for the NAD⁺-boosting activity of PQQ and a rationale for experimental validation. Full article

The effects of red seaweed, psyllium husk, and chia seeds on the structural and functional properties of comminuted meat batters were evaluated. Meat batters were formulated with 1% of each ingredient or their combinations totaling 1% and evaluated for pH, cooking loss, microstructure, texture profile analysis, color, rheology, and protein interactions. Formulation did not affect (p ≥ 0.08) pH or cooking loss, indicating that water- and lipid-holding capacity and emulsion stability were preserved across treatments. Hardness increased (p ≤ 0.05) in treatments containing red seaweed, alone or combined with psyllium husk. Fiber addition did not influence (p ≥ 0.17) raw batter color; however, cooked products showed differences (p ≤ 0.05) in lightness (L*) and total color change (ΔE*). Rheological analysis indicated similar viscoelastic behavior among treatments with no significant differences among treatments (p ≥ 0.07) for storage modulus, loss modulus, or tangent delta at the start, peak, or end of the small-amplitude oscillatory shear test. Microstructural observations revealed treatment-dependent networks, and protein solubility analysis showed changes (p ≤ 0.05) in ionic and hydrogen bonding, while disulfide bonds were unaffected (p = 0.60). Incorporation of 1% of these ingredients maintained desirable physicochemical, textural, and functional properties, highlighting their potential as ingredients in meat batters. Full article

Three new hybrid bis(salicylaldiminato)/calix[⁴]arene ligands H₄L1–H₄L3 have been synthesized and investigated with regard to their coordination behavior toward the UO₂²⁺ cation. The ligands H₄L1 and H₄L2, derived from bis-1,3-amino-ethoxy-functionalized calix[⁴]arenes and 3-methoxy-2-hydroxy-salicylaldehydes, react readily with uranyl nitrate in the presence of NEt₃ to support mononuclear neutral complexes with a 1:1 metal:ligand stoichiometry, namely [UO₂(H₂L1)] (6) and [UO₂(H₂L2)] (7). Ligand H₄L3, with an additional alanyl linker connecting the bis(2-amino-ethoxy)-calix[⁴]arene backbone and the 3-methoxy-2-hydroxy-salicylaldehyde arms, supports a neutral, mixed-ligand dinuclear uranyl complex [(UO₂)₂(MeO)₂(H₂L3)] (8). The ligands H₄L1 and H₄L2 act as pentadentate O₄N ligands for the UO₂²⁺ ion to produce a distorted pentagonal bipyramidal coordination environment (O₆N donor set). The ligand H₄L3 supports a binuclear [UO₂(μ-OMe)₂UO₂]²⁺ core unit, whose terminal coordination sites are occupied by the donors of the two pendant arms of H₄L3. The spectroscopic properties (NMR, IR, UV-Vis, ESI-MS) suggest that the complexes 6 and 7 retain their integrity in solution state. The structures are further stabilized by intramolecular hydrogen bonding interactions, as implied by computational analyses (NCI plots). These findings provide valuable insight into the influence of spatial flexibility and donor arrangement on the uranyl coordination chemistry of calix[⁴]arene-based ligand systems. Full article

The transition toward renewable and environmentally responsible materials has intensified interest in cellulose-based systems for use in sustainable packaging applications. Although cellulose offers biocompatibility, structural versatility, and tuneable physicochemical properties, conventional modification routes rely on harsh chemicals and generate environmentally burdensome effluents. In this study, an efficient and a potentially green strategy for cellulose modification was developed using acid-based deep eutectic solvents (DES) composed of choline chloride and lactic, acetic, or citric acid at different molar ratios. Under mild conditions (110 °C, 4 h), DES pretreatment reduced glucan content in sulphite pulp from 99% to 79–93%, depending on the hydrogen bond donor (HBD), while suggesting an apparent increase in relative crystallinity, from approximately 82% to 90%, as estimated by the Segal method. FTIR, XRD, and morphological analyses revealed the disruption of the hydrogen bonding network, enhanced fibrillation, and residual DES-derived functional groups detectable by FTIR. Although DES pretreatment increased structural order, it also reduced enzymatic digestibility due to the higher proportion of crystalline domains. Overall, the results demonstrate that acidic DES constitutes a sustainable and recyclable medium capable of modulating cellulose structure and generating materials with enhanced physicochemical properties. These findings suggest that DES-modified cellulose could serve as a potential reinforcement platform for future biodegradable packaging and bioplastic formulations, enabling the development of high-performance, renewable, and environmentally compliant packaging materials. Full article

Radix Paeoniae Alba, the dried root of Paeonia lactiflora Pall., contains characteristic monoterpene glycosides, but efficient recovery of these polar constituents remains challenging. This study developed an ionic liquid-assisted sequential ultrasound–microwave extraction method and evaluated paeoniflorin, oxypaeoniflorin and albiflorin by HPLC as multi-marker responses. Among the ionic liquids tested, 1-propyl-3-methylimidazolium dihydrogen phosphate showed the best extraction response. Box–Behnken response surface optimization gave practical extraction conditions of a solid-to-liquid ratio of 1:26 g/mL, ionic liquid concentration of 0.12 mol/L and ultrasound time of 22 min. Under these conditions, paeoniflorin and total marker glycosides reached 29.12 and 34.98 mg/g dry material, respectively, representing increases of 32.4% and 34.5% compared with conventional reflux extraction. UPLC-QTOF-MS profiling provided complementary chemical profile information for the optimized extract and tentatively annotated Paeonia-related monoterpene glycoside derivatives, galloylated glucose derivatives and polyphenolic constituents. Electrostatic potential, SAPT and non-covalent interaction analyses, supported by ¹H NMR chemical shift perturbation, suggested possible hydrogen bonding, electrostatic and dispersion interactions between paeoniflorin and the selected ionic liquid. These results support the optimized process as an efficient extraction approach and provide molecular interaction insights into ionic liquid-assisted recovery of monoterpene glycosides. Full article

Herein, a novel insensitive diazonium inner salt of 2-nitro-5-oxo[1,2,4]triazolo[1,5-c]pyrimidin-8-diazonium-7-olate (NTPD) was synthesized through a concise three-step route. The structure and performance of this material were comprehensively studied. Single-crystal X-ray diffraction analysis revealed that NTPD possesses a distinctive fused-ring framework featuring an inner salt (zwitterionic) structure, wherein the diazonium and phenolate functionalities are intramolecularly integrated within a compact, highly conjugated heterocyclic system. Furthermore, in comparison with previously reported diazonium compounds, NTPD exhibits a superior combination of enhanced thermal stability and significantly reduced mechanical sensitivity. Specifically, its onset decomposition temperature reaches 206 °C, representing a substantial improvement over conventional diazo derivatives, while its impact sensitivity of 7 J positions it among the least sensitive diazonium-based energetic materials reported to date. The exceptional performance of NTPD is strongly attributed to its nearly planar molecular geometry and the extensive hydrogen-bonding network present within its crystal lattice, which collectively reinforce structural rigidity, enhance packing stability, and effectively dissipate external mechanical stimuli. Full article

The occurrence of pharmaceutical residues in aquatic environments has become an important environmental challenge, encouraging the development of sustainable and low-cost treatment technologies. In this study, eggshell waste in the form of eggshell without membrane (ES) and eggshell with membrane (ESM) was investigated as a biosorbent for the removal of levomepromazine from aqueous solutions. The materials were characterized by XRD, FTIR, SEM–EDS, TGA, and pH_PZC analyses, confirming the predominance of calcite and the presence of functional groups potentially involved in adsorption. Batch adsorption experiments were conducted to evaluate the effects of pH, adsorbent dosage, contact time, initial levomepromazine concentration, and temperature. The adsorption capacity increased with increasing pH, reaching optimum performance under alkaline conditions, while equilibrium was attained within approximately 60 min. Kinetic data were best described by the pseudo-second-order model (R² > 0.99). Equilibrium studies showed that the Freundlich model provided the best fit to the experimental data, suggesting adsorption on heterogeneous surfaces. Regeneration experiments demonstrated that both adsorbents retained a substantial fraction of their adsorption performance after five adsorption–desorption cycles. FTIR analyses after adsorption and pH_PZC measurements suggest that electrostatic interactions and hydrogen bonding may contribute to levomepromazine uptake. Response surface methodology identified adsorbent dosage and initial concentration as the most influential operating parameters. Overall, the results demonstrate the potential of eggshell-derived materials as low-cost biosorbents for levomepromazine removal from aqueous media. Full article

Electrospun composite nanofibers represent an emerging strategy for the development of efficient fertilizer systems, as they enable modulation of the structural properties of the nanofibrous network and, consequently, the transport and release processes of nutrients. In this study, polyvinyl alcohol (PVA) nanofibers loaded with two different urea contents (0.09 g and 0.36 g) were fabricated and characterized to investigate how urea incorporation modifies the nanofiber morphology and influences urea release kinetics. SEM and EDS analyses confirmed that increasing urea content promotes surface roughnes and reduced nanofiber diameters, whereas XRD and FTIR demonstrated a decrease in crystallinity and the formation of hydrogen-bonded interactions between PVA chains and urea molecules, indicating that urea is incorporated within the PVA network rather than being superficially adsorbed on the nanofiber surface. These structural changes govern water retention and release kinetics: the 0.36 g formulation exhibited a 100-h induction period followed by multiphase diffusion, while the 0.09 g system displayed immediate release but lower final concentrations. Kinetic modeling revealed excellent fitting to the Higuchi and second-order models, confirming diffusion-controlled urea release modulated by internal interactions. The nanofiber network thus behaves as an active regulator of nitrogen mobility, overcoming the limitations of conventional coating-based fertilizers. These findings demonstrate the potential of PVA/urea nanofibers as scalable platforms for sustainable nitrogen delivery in agriculture, bridging morphology-driven polymer design with environmental performance. Full article

Fluid-loss additives play a critical role in maintaining the stability and filtration-control performance of water-based drilling fluids during deep and high-temperature drilling operations. However, the development of microgel-based additives with both exceptional thermal stability and strong salt tolerance remains a major challenge under harsh drilling conditions. In this study, a covalently micro-crosslinked anionic copolymer-based microgel (PAAN) was synthesized via free-radical copolymerization of acrylamide, 2-acrylamido-2-methylpropane sulfonic acid, and N-vinylpyrrolidone using N,N′-methylenebisacrylamide as the crosslinking agent. The chemical structure of PAAN is consistent with the design, with excellent thermal stability, and the starting temperature for thermal decomposition of polymer molecular chains is 297 °C. The weight average molecular weight of PAAN is 1.3396 × 10⁶ g/mol. After aging at 220 °C in the presence of 15 wt% NaCl, the PAAN-containing drilling fluid exhibited a high-temperature high-pressure filtration loss of only 15.6 mL. Even after prolonged aging for 168 h, the filtration loss remained at a relatively low level of 46.0 mL, indicating outstanding thermal stability and salt tolerance. Mechanistic analysis indicated that PAAN adsorbed onto bentonite surfaces through electrostatic interactions and hydrogen bonding, promoting clay-particle dispersion and colloidal stability. Moreover, the microgel network facilitated the formation of a compact and low-permeability filter cake, contributing to effective fluid-loss control under harsh conditions. These results demonstrate that microgel structural design is an effective strategy for improving the high-temperature and salt-resistant filtration-control performance of WBDFs, and PAAN shows strong potential for deep and ultra-deep drilling applications. Full article

This study investigates citrus peel powder (CP) as an environmentally friendly admixture to regulate plant-derived urease (with soybean powder (SP) as the urease source) and to promote bio-mediated CaCO₃ mineralization, thereby improving the mechanical and freeze–thaw (FT) resistance properties of cement-based materials. When CP is combined with urea and soybean urease, it exhibits a regulatory effect on urease activity. For the CPUD (CP-encapsulated urea combined with soy powder)-modified material with SP dosage in cement content of 0.2 wt%, the CP–urea modification treatment can effectively improve their mechanical properties and FT durability. The flexural and compressive strengths at 28 days are increased by 10.53% and 11.19%, respectively, compared to the blank group. After freeze–thaw cycles, the strengths are still 27.08% and 26.67% higher than those of the blank group, and their respective strength loss rates are 7.58% and −5.77% (negative indicating a net strength increase), compared with 21.31% and 9.48% for the blank group. X-ray diffraction, Fourier-transform infrared spectroscopy, and scanning electron microscopy analyses reveal that CP–urea promotes the formation and effective packing of calcium carbonate. Mechanistically, CP establishes a stable hydrogen-bonding network with both urea and urease, exerting a dual regulatory effect: it enhances the electrophilicity of urea while also creating a physical mass transfer barrier to precisely control biomineralization. Notably, CP can be directly used without pretreatment, offering a sustainable strategy for citrus peel waste valorization. Full article