Search Results (1,043)

Currently, the resource wastage and safety hazards caused by fruit and vegetable spoilage are becoming increasingly prominent. Developing green, efficient, and non-toxic novel preservation materials has emerged as a hot spot in fruit and vegetable research. Based on this, this study utilized pomegranate peel as a raw material to prepare spherical multifunctional carbon dots (P-CDs) with an average particle size of 1.98 ± 0.58 nm through a one-step hydrothermal reaction. Subsequently, P-CDs were co-incorporated with L-cysteine (L-Cys) into a polyvinyl alcohol (PVA) and chitosan (CS) matrix to construct a novel composite coating material with combined antibacterial, antioxidant, and preservation functions. Experimental results demonstrate that P-CDs exhibit outstanding antioxidant activity and antibacterial performance. Compared to PVA/CS film, the P-CDs/L-Cys/PVA/CS film exhibited a 6.55 MPa increase in tensile strength and significantly enhanced thermal stability. Furthermore, the incorporation of P-CDs and L-Cys markedly boosted the PVA/CS film’s antioxidant activity (97% for ABTS; 85.69% for DPPH), antibacterial performance, and ultraviolet (UV) shielding capability. Coating cherry tomatoes with the P-CDs/L-cysteine/PVA/CS composite extended their shelf life by 6 days. This composite coating material exhibits preliminary biocompatibility and eco-friendly properties, aligning with green sustainable development needs and offering a novel potential solution for food preservation technology, while its practical applicability to food safety requires further comprehensive verification. Full article

Polyethylene terephthalate is a prominent polymer known for its mechanical properties, chemical resistance, and recyclability, and it is widely utilized across various industries. Enhancing the properties of polyethylene terephthalate (PET) through nanocomposite technology, particularly with the inclusion of nanoscale fillers, has garnered significant attention. This study investigates synthetic layered double hydroxides (LDHs), specifically MgAl LDH modified with calcium dodecylbenzene sulphonate in n-butyl alcohol (CDS) organic surfactant, as an alternative to natural clays for PET nanocomposites. Additionally, modified LDH serves a dual role as both a catalyst and a dispersive agent, promoting effective exfoliation within the PET matrix. A polymerization process was employed to ensure proportional and effective dispersion of the nanofillers, addressing the critical challenge of achieving uniform distribution. The resulting nanocomposites demonstrated superior mechanical strength, thermal stability, and barrier properties compared to traditional intercalated counterparts. Moreover, synthetic LDHs present a more sustainable solution, reducing the environmental footprint associated with natural clay mining, which includes land degradation, water pollution, energy consumption, and biodiversity loss. This research provides a promising pathway for developing high-performance, environmentally friendly PET nanocomposites, with significant implications for various industrial applications, from packaging to automotive and electronics. The findings highlight the potential of synthetic LDHs to advance material science while aligning sustainable development goals. Full article

Flocs, visible particles formed in sugar-sweetened beverages, reduce clarity and consumer acceptance of products. Their presence can be caused not only by different types of trace impurities in the sugar but also by interactions among beverage components. In this review, scientific reports on acid beverage flocs (ABFs) and alcohol flocs are summarized, the main pathways for their formation are described, and practical options for detecting them and preventing their formation in beverages are compiled. Using Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 and related guidance, literature searches of Scopus, Web of Science (WoS), PubMed, Food Science and Technology Abstracts (FSTA), CAB Abstracts, and International Commission for Uniform Methods of Sugar Analysis (ICUMSA) resulted in the inclusion of 56 studies. In various types of beverages, complexes formed between proteins (Ps) and polyphenols (PPs) often initiate haze and floc formation, while polysaccharides (dextran, pectin, and starch), silica or silicates, and inorganic ions influence charge balance, particle bridging, and floc growth rate. Ethanol in alcohol beverages can further destabilize colloids and promote aggregation. For beet sugars, saponin–protein interactions are a likely pathway for the formation of ABF, but the available evidence is not consistent. In cane sugars, the reported roles of proteins, polysaccharides, silica, and starch in floc formation vary considerably between studies. For quality assurance, ICUMSA floc tests (GS2-40 and GS2-44) should be complemented by turbidity or haze measurement and colloid characterization such as light scattering, ζ–potential, and infrared IR-based analytical methods supported by chemometrics. Risk mitigation works best as a two-level strategy that combines impurity removal during sugar production and stabilization steps in beverage formulation and storage, including the use of clarification agents and control of pH, temperature, ionic strength, and oxygen exposure. Standardized reporting and validation of rapid predictors against ICUMSA benchmarks remain essential. Full article

Conventional cement-based foamed lightweight soil (FLS) faces cost and environmental challenges. This study develops a sustainable polyvinyl alcohol (PVA) fiber-reinforced solid waste-based FLS (PVA-SWFLS) by entirely replacing cement with a ternary system of red mud, granulated blast furnace slag, and fly ash. PVA fibers were incorporated to mitigate inherent brittleness and cracking. The effects of fiber content (0–0.9 vol%), length (3–15 mm), water–binder ratio (0.35–0.55), and wet density (550–950 kg/m³) on the fluidity and compressive strength were evaluated, along with analyses of microstructure and pore characteristics using scanning electron microscopy and mercury intrusion porosimetry. Findings reveal that fiber addition reduces flowability (up to 34.9%) but significantly bolsters compressive strength, depending on fiber content and length. For 0.3% and 0.5% contents, optimal fiber lengths of 12 mm and 9 mm were observed, respectively; the 28-day compressive strength reached a maximum of 2.97 MPa at the 0.3% content with 12 mm fibers. Beyond these optimal points, and particularly for higher contents (0.7–0.9%), strength decreased monotonically with increasing fiber length due to fiber agglomeration and reduced compactness. Furthermore, strength correlated positively with wet density and negatively with the water–binder ratio, while fluidity increased with both. The hierarchy of influence was identified as: fiber content > fiber length, and wet density > water–binder ratio, while all four parameters significantly governed fluidity. The stress–strain behavior under different parameter combinations was analyzed, and a parametric constitutive model was established to support practical applications. Full article

Bamboo is widely available and renewable. Using bamboo blocks to partially replace coarse aggregates in the production of concrete solid bricks shows promising application prospects in areas such as nonload-bearing wall materials. However, as a natural biomass material, bamboo squares have disadvantages such as susceptibility to decay, water absorption, swelling, and drying shrinkage, necessitating modification when used as concrete coarse aggregate. This study subjected raw bamboo squares to high-temperature carbonization. The compressive performance of concrete made with these carbonized bamboo squares was first tested and compared with concrete containing raw bamboo squares. Subsequently, both raw and carbonized bamboo squares were modified using conventional methods: polyvinyl alcohol (PVA) treatment, epoxy mortar (EM) treatment, epoxy resin (EPR) treatment, water glass (WG) treatment, and glutinous rice glue treatment. Modified bamboo block concrete specimens were prepared, and their compressive strengths were tested and compared. The results indicated that the compressive mechanical performance of carbonized bamboo block concrete consistently outperformed that of raw bamboo block concrete across all substitution rates. Specifically, the optimal modification method—using epoxy mortar (EM) encapsulation—significantly enhanced the mechanical properties. At a high volumetric replacement rate of 30%, the EM-modified carbonized bamboo concrete achieved a compressive strength of 27.79 MPa, which is 15.1% higher than that of identically treated raw bamboo concrete and far exceeds the standard MU7.5 grade requirements. These quantitative findings provide a solid experimental and theoretical basis for the high-value application of bamboo squares in sustainable concrete solid bricks. Full article

Ventricular septal defect (VSD) occluders commonly rely on permanent nitinol frameworks, which may contribute to long-term mechanical mismatch and late complications. Here, we developed a tissue-compliant composite membrane by embedding a 3D-printed poly(vinyl alcohol) (PVA) grid within a shape-memory poly(glycerol dodecanedioate) (PGD) matrix. Grid spacing was varied from 0.1 to 0.5 mm to tune reinforcement density. FTIR indicated that PVA was incorporated mainly through physical interlocking rather than new covalent bonding. The composite preserved near-body-temperature shape recovery. In water at 37 °C, PVA reinforcement increased tensile modulus and fracture strength, although swelling also increased. Finite-element analysis and benchtop occlusion testing consistently showed lower deformation, less strain localization, and smaller bulge height for PGD–PVA than for PGD alone. In vitro assays showed low cytotoxicity, low hemolysis, and prolonged plasma recalcification time. A 12-week pilot degradation study showed that the faster mass loss observed in initial samples was mainly caused by exposed PVA cut edges; after switching to a fully encapsulated design, static mass loss became similar across groups, and dynamic PBS agitation produced about 10% mass loss at 12 weeks. These results support PGD–PVA as a reinforced membrane strategy for polymeric occluders. Full article

Segmental bone defects are large, non-healing injuries characterized by insufficient structural support and limited bioactivity, posing a significant clinical challenge. In this study, we developed biomimetic chitosan/polyvinyl alcohol–glycerol (CS/PG) scaffolds inspired by porcupine quills, which were fabricated via fused deposition modeling and unidirectional freeze casting. The as-prepared scaffold featured a dense outer layer of polyvinyl alcohol–glycerol (PG) with high compressive strength (24.21 ± 0.11 MPa at 25% strain) and an oriented inner foam of chitosan (CS). The CS foam was further incorporated with poly (3,4-ethylenedioxythiophene) polystyrene sulfonic acid (PEDOT:PSS, denoted as PP) and amorphous zinc phosphate (AZP) to form PP-AZP-CS/PG, aimed at enhancing neural conductivity and stimulating blood vessel formation, respectively. The in vitro results indicated that the biomimetic scaffolds exhibited excellent biocompatibility while significantly enhancing angiogenesis and osteogenesis capabilities. In a rabbit radial segmental defect model, PP-AZP-CS/PG achieved robust bone regeneration, attaining a bone volume/total volume of approximately 26.22% after implantation for 8 weeks. Overall, this biomimetic scaffold demonstrated that integrating hierarchical design with additional bioactive components enhanced mechanical support while promoting new bone regeneration, addressing critical challenges in segmental bone defect repair. Full article

This study develops a multi-scale fiber-reinforced cementitious composite (MFRC) by hybridizing calcium carbonate whisker (CW), polyvinyl alcohol (PVA) fiber, and steel fiber. The interfacial micromechanical properties between steel fiber/matrix and PVA fiber/matrix under the influence of CW were systematically examined through single-fiber pull-out tests. The two-dimensional and three-dimensional distribution characteristics of fibers in the MFRC were analyzed using backscattered electron imaging (BSE) and X-ray computed tomography (X-CT), respectively. Based on the fiber distribution characteristics, flexural strength prediction models were developed with R² values of 0.79 (2D) and 0.82 (3D). Experimental validation via splitting tensile tests and three-point bending tests confirmed the model’s effectiveness in simultaneously predicting splitting tensile strength (R² = 0.89) and flexural strength (R² = 0.93). These findings demonstrate the reliability and universality of the proposed model for predicting flexural–tensile strength in an MFRC. Full article

This study evaluates viticultural parameters of the Golia grape variety in relation to variable climatic conditions over the 2020–2024 period and analyzes their impact on wine quality. The data show significant climatic variability, with warming trends causing earlier flowering and ripening by 11–13 days. Grape production varied depending on climatic conditions, with 2021 and 2024 recording the highest number of shoots per trunk and increased fertility in 2024. Low winter temperature led to reduced bud viability and affected the overall health of the vines and harvest yields. Average annual precipitation, especially from the growing season, significantly influenced actual yield (AY), while higher annual temperatures and sunshine duration (Sun) resulted in lower grape weight. Greater sugar concentrations accumulated in years with higher temperatures, while higher acidity levels registered at lower temperatures. Higher precipitation (Pp) coupled with thermal accumulation promoted higher dry extract and alcoholic strength (AS), significantly enhancing the perception of honey notes (R² > 0.7, p-value < 0.05). Furthermore, higher thermal regimes negatively impacted the expression of delicate aromatic compounds, diminishing specific notes such as rose and exotic fruits. Full article

Transcutaneous electrical nerve stimulation (TENS) is constrained by high skin impedance and unstable electrode contact. This study proposes a novel composite electrode system comprising a polyvinyl alcohol/silver (PVA/Ag) microneedle array and a highly conductive polyacrylamide/lithium chloride (PAAm/LiCl) hydrogel. The PVA/Ag microneedles (~365 µm in height, ~48 µm tip diameter) possess sufficient mechanical strength to penetrate the stratum corneum, establishing a low-resistance pathway. The complementary PAAm/LiCl hydrogel exhibits high conductivity (10.28 S/m) and mechanical flexibility, further optimizing the interface contact. The experimental results demonstrate that this composite system achieves low electrochemical impedance and induces stable, clear electromyographic responses in vivo. It effectively addresses the common issues of electrode detachment and signal attenuation associated with conventional electrodes, offering a promising hardware solution for efficient and comfortable wearable rehabilitation devices. Full article

Polyvinyl alcohol (PVA) fibers are commonly added to fiber-reinforced geopolymer composites (FRGC) to enhance their properties; however, systematic research on the dynamic mechanical properties of polyvinyl alcohol fiber-reinforced geopolymer composites (PVA-FRGC) is still required. In this study, an orthogonal experimental design was adopted to investigate the effects of the fly ash/slag ratio, fiber length, and fiber volume content on the dynamic mechanical properties (dynamic compressive strength, fragmentation degree, and energy absorption capacity) of PVA-FRGC. A split Hopkinson pressure bar (SHPB) was used to test the dynamic mechanical properties of the material. The results indicate that the fly ash/slag ratio, fiber length, and fiber volume content all exert significant effects on the dynamic compressive strength and energy absorption capacity of PVA-FRGC. The addition of PVA fibers significantly improves the dynamic compressive strength of PVA-FRGC, which reaches 157.52 MPa, 183.26 MPa, and 210.68 MPa under three different strain rates ranging from 75.4 s⁻¹ to 179.6 s⁻¹, respectively. Although the energy absorption capacity of PVA-FRGC is not significantly improved, the integrity of the specimens after fragmentation is remarkably enhanced. Specifically, under the three load levels, the average particle sizes of PVA-FRGC are 241.43%, 245.04%, and 127.80% higher than those of plain geopolymers, respectively. Considering the comprehensive dynamic mechanical properties, a fly ash/slag ratio of 5:5, a fiber length of 9 mm, and fiber volume content of 2.0% can be regarded as the local optimal mix proportion. Full article

The textile industry faces significant challenges regarding the need for textile waste recycling. This study investigates the feasibility of alkaline hydrolysis assisted by alcoholic co-solvents, such as ethanol, for recycling polyester/cotton blend textiles. Ethanol-assisted alkaline hydrolysis under mild conditions enabled almost complete depolymerisation of polyester, allowing the recovery of its monomers, terephthalic acid and ethylene glycol, which may be used to produce new polyester fibre. However, the treatment was found to adversely affect the properties of the cotton fibres, resulting in a recycled material of lower quality and functionality than the original material. In particular, a significant change in the structure of the cotton fibre was observed, namely, the transformation of cellulose I into cellulose II, as confirmed by FTIR analysis, along with a decrease in both the degree of polymerization and tensile strength, especially at an ethanol/water ratio of 40/60. Hence, alcohol-assisted alkaline hydrolysis is advisable for the chemical recycling of polyester, but it presents limitations when cotton fibres are also present. Full article

Three-dimensional printing (3DP) has gained increasing attention in construction as a means of addressing labor shortages and improving efficiency. Various studies have investigated fiber-reinforced mortars for 3DP. However, only a few studies have examined mixture design strategies aimed at controlling early structural build-up, and the relationships between early structural build-up, printability, and interlayer stability remain largely unexplored. This study aimed to establish a practical method for evaluating the static yield stress and early buildability of 3DP mortars under construction-site conditions. Vane shear and 15-stroke flow tests were conducted to assess the static and dynamic behavior of mortars incorporating polyvinyl alcohol (PVA) fibers, and their compressive and flexural strengths were also evaluated. According to the results, the vane shear test sensitively captured the rheological changes associated with variations in fiber content and superplasticizer dosage. The addition of PVA fibers increased the maximum shear stress of the mortar, resulting in atypical static yield stress development compared to fiber-free mortars. While the 15-stroke flow test further elucidated flowability, the vane shear test revealed a stronger correlation between mechanical properties and overall buildability. Thus, vane shear testing can be reliably used to assess early-age structural build-up and interlayer stability in 3DP mortars for optimizing print performance. Full article

The development of bioplastic films represents an alternative to conventional plastics and an opportunity for applications in intelligent packaging. The present study aimed to develop a smart material based on poly (vinyl alcohol) (PVA) incorporated with Clitoria ternatea L. extract, capable of monitoring shrimp freshness through colour changes associated with pH variations. The films were prepared using the casting method and characterised in terms of their physical, mechanical, structural, and functional properties. The incorporation of the anthocyanin extract (EAC) significantly intensified the colouration of the films, decreasing lightness (L*) from 88.7 to 37.1 and modifying the chromatic parameters (b from −0.16 to −22.34). Thickness increased from 109.5 μm to 184 μm as the extract concentration was raised, while water vapour permeability ranged from 0.77 to 1.79 g·m/m²·s·Pa, evidencing modifications in the structure of the polymeric matrix. From a mechanical standpoint, tensile strength decreased from 26.0 MPa to 15.2 MPa, and the elastic modulus was reduced by approximately 75.0 MPa, whereas the percentage elongation at break increased from 75.2% to 92.4%, confirming the plasticising effect of the extract. Functionally, the films exhibited a visible transition from blue to green during the refrigerated storage of shrimp, corresponding to increases in pH from 6.6 to 9.2 and total volatile basic nitrogen (TVB-N) values from 3.92 to 67.7 mg N/100 g. The formation of TVB-N followed first-order kinetics (R² = 0.997), confirming the sensitivity of the system as a freshness indicator. These results demonstrate the potential of PVA–anthocyanin films as intelligent colorimetric sensors for monitoring the freshness of protein-rich foods. Full article

In this study, we developed an eco-friendly intumescent flame-retardant coating for polyester (PET) fabrics. The coating was formulated with aluminum diethylphosphinate-based flame retardant (P-FR), trisilanol isobutyl-POSS (Si-FR), sericin (SC), and poly(vinyl alcohol) (PVA), using citric acid (CA) as a chemical crosslinker. The coatings were applied to alkaline-treated PET fabrics via the knife-coating technique, followed by drying and curing. P-FR acted as the primary flame-retardant component, while SC and Si-FR served as N/Si synergistic agents that enhanced the performance of P-FR, as demonstrated by an improvement in the UL 94 rating from V-1 to V-0. Thermogravimetric analysis indicated that SC and Si-FR improved the oxidative stability of the char. Flame-retardant finishing increased the limiting oxygen index (LOI) from 21.1% for untreated fabric to 31.7% for treated fabric, while tensile strength increased and elongation at break decreased. Notably, after 50 washing cycles, the treated fabrics retained self-extinguishing behavior, although the UL 94 classification decreased to V-2. Overall, this halogen-free coating system effectively enhanced the flame retardancy of PET fabrics while using environmentally friendly components, indicating its potential for sustainable flame-retardant textile applications. Full article