Search Results (626)

Objective: This study aimed to evaluate the long-term degradation behavior, biostimulatory effects, and biocompatibility of a novel poly-L-lactic acid-block-polyethylene glycol/hyaluronic acid (PLLA–b–PEG/HA) composite filler for soft tissue augmentation. Methods: PLLA–b–PEG/HA microsphere properties were characterized via scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance hydrogen spectroscopy (¹H NMR), thermogravimetry (TG) and differential scanning calorimetry (DSC). A 104-week in vivo rabbit model was established to systematically observe filler degradation and tissue responses. Ultrasound monitoring, histological staining, ELISA and RT-PCR were performed to assess volumetric changes, inflammatory reactions and collagen synthesis-related signaling. Results: Physicochemical property tests demonstrated that PLLA–b–PEG retains the fundamental physicochemical properties of pristine PLLA while exhibiting enhanced hydrophilicity. B-ultrasound demonstrated a presented uniform in vivo distribution without displacement or diffusion over time, confirming steady and predictable degradation. SEM verified progressive morphological degradation and porous evolution of the microspheres. The filler induced a mild, balanced inflammatory microenvironment with early expression of both pro-inflammatory (IL-12, TNF-α) and anti-inflammatory (IL-4) cytokines, which resolved gradually over time. Sustained TGF-β upregulation persisted throughout the 104-week observation period, driving continuous neocollagenesis and prominent neoelastogenesis, thereby achieving favorable and long-term tissue remodeling with excellent biocompatibility. Conclusions: The PLLA–b–PEG/HA composite filler exhibits controllable degradation properties and homeostatic regulatory effects, along with outstanding long-term biosafety and tissue integration capacity. As an ideal biostimulatory filler for soft tissue augmentation, it can effectively facilitate the regeneration of high-quality functional extracellular matrix rich in collagen fibers and elastic fibers, and holds promising clinical prospects for natural and long-lasting soft tissue filling applications. Full article

To reduce the high post-harvest losses of perishable fruits due to fungal spoilage, a novel, self-healing, active multilayer coating based on green polymer chemistry was developed. The system was constructed by the layer-by-layer technique from a dual-modified pullulan polyelectrolyte pair—pullulan maleate and enzymatically derived pullulan betaine with incorporation of β-cyclodextrin/neem oil inclusion complex (β-CD/NO). SEM and DSC analyses confirmed the successful formation of the complex and the structural transition to a rough topography. Due to strong interlayer electrostatic interactions and β-CD as a rigid filler, the multilayer films with the active complex achieved the highest tensile strength of 1.30 ± 0.61 MPa (up to 4× increased in comparison to the monolayer films), with a decrease in elasticity to 10.84%. Additionally, water vapor permeability values were reduced by 22%–28% compared to related biomatrices, while rapid, water-activated self-healing successfully repaired physical film damage. In vitro testing against Candida albicans showed a pronounced synergistic effect with a zone of inhibition of 16.5 ± 1.1 mm for the active formulation. During seven-day in vivo testing on fresh figs, the active coating effectively suppressed yeast proliferation at room temperature (maintaining levels at 2.1 log CFU/g versus 7.1 in untreated figs) and under refrigerated conditions. This innovative system represents a highly promising and sustainable platform for active food packaging. Full article

The growing demand for sustainable food packaging has spurred interest in biodegradable active films. This study aimed to develop novel polylactic acid/tetraethyl citrate (PLA/TEC) composite films reinforced with curcuma, mustard, and ginger powders for extending the shelf life of fresh minced meat. Films incorporating 5, 10, and 15 wt% of each powder were prepared via melt extrusion and compression, and characterized by XRD, FTIR, tensile testing, oxygen barrier measurements, DPPH antioxidant assays, and antibacterial tests against Listeria monocytogenes and Escherichia coli. Optimal 10 wt% formulations were applied to fresh minced pork and evaluated for microbial quality, lipid oxidation, and sensory properties over 8 days at 4 °C. Curcuma powder exhibited the strongest plasticizing effect, increasing elongation at break up to 410%, while ginger acted as a reinforcing filler. The 10 wt% formulations provided the best oxygen barrier (OTR: 55.4–61.8 cc/m²·day). Curcuma showed the highest antioxidant activity (EC₅₀ = 34.4 mg/mL at 15 wt%), followed by ginger and mustard, while antibacterial activity was moderate for all films. In meat packaging tests, all three active films extended shelf life by approximately 2 days compared to PLA/TEC, with curcuma-based films showing the best overall performance in delaying microbial growth and lipid oxidation. The PLA/TEC matrix effectively accommodated high loadings of natural spice powders, yielding flexible, fully bio-based active films. Curcuma-containing films demonstrated the most promising balance of properties, offering a viable sustainable alternative for fresh meat packaging. Full article

In the last few years, the tyre industry has faced new sustainability challenges, mainly regarding the substitution of fossil-based ingredients with bio-based raw materials. In fact, most of the largest tyre companies worldwide have publicly declared the objective of producing tyres with 100% sustainable materials by 2050. The main ingredients in a tyre compound are the polymer matrix and the reinforcing filler, but while natural rubber (NR) already represents a well-established bio-based alternative to synthetic polymers, the replacement of conventional reinforcing fillers remains a significant challenge. In fact, carbon black (CB), a fossil-based raw material produced from petroleum-derived feedstock, is still the main filler used in rubber compounds worldwide. A promising candidate for its replacement could be Microfibrillated cellulose (MFC): a bio-based, biocompatible, renewable, and non-toxic material, also obtained from waste biomass, with a lower density and a higher surface reactivity with respect to CB. However, the polar functional groups on its surface make it extremely incompatible with the non-polar rubber matrices used for tyre formulations. To overcome this limitation, effective compatibility strategies are required to exploit and boost these surface functionalities and promote the formation of a novel filler–polymer network. In this work, a new approach for MFC functionalisation is developed, and the synthesis and characterisation of the modified material are reported. This strategy is further applied to develop innovative MFC-reinforced epoxidised natural rubber (ENR) compounds, whose properties are compared to conventional CB-filled systems. Full article

Redox flow batteries (RFBs) are an interesting option for long-term energy storage. A well-performing membrane sits at the heart of the electrochemical battery cell and should effectively mitigate crossover of active species while minimizing resistance. However, current commercial membranes are rather expensive and demonstrate sub-optimal performance, leading to an extensive search for alternatives. Research on membranes for RFBs has long been dominated by dense ion-exchange membranes and porous membranes, both potentially with fillers. In recent years, increased interest in alternative morphologies such as thin-film composites (TFCs) has ignited new research directions. TFCs consist of a thin dense layer on top of a porous support, aiming to merge the advantages of both. Traditionally, TFCs are made using polyamide top layers. In this paper, a novel chemistry is developed with increased chemical stability for RFBs. Poly(vinylbenzyl chloride) is crosslinked interfacially with a diamine, demonstrating for the first time the potential of support-mediated interfacial crosslinking with two immiscible solvents. Optimization of the support, amine crosslinker, reaction time and synthesis procedure allowed a shift of the trade-off between vanadium crossover and proton transport, highlighting the opportunities for this promising TFC chemistry. Full article

To enhance the high-temperature rutting resistance, fatigue performance and low-temperature cracking resistance of base asphalt, and promote the resource utilization of industrial solid waste, this study took 70# asphalt as the base asphalt and selected nano-montmorillonite (MMT) and fly ash (FA) as composite modified fillers. A series of composite modified asphalt samples was prepared with MMT:FA mass ratios of 1:2, 1:3 and 1:4 and total filler contents of 3%, 5% and 7%, respectively. Conventional physical tests, dynamic shear rheometry (DSR), multiple stress creep recovery (MSCR), linear amplitude sweep (LAS) and bending beam rheometry (BBR) were adopted to systematically evaluate the pavement rheological properties. The microscopic modification mechanism was revealed by thin-layer chromatography with flame ionization detection (TLC-FID) and gel permeation chromatography (GPC). The results show that MMT-FA composite filler can significantly reduce the penetration, increase the softening point, and greatly enhance the high-temperature rutting factor, creep-recovery rate and fatigue life of asphalt, while its influence on low-temperature performance is controllable. For the optimal group, S5, the rutting factor rises by 42.6% at 64 °C, and the fatigue life increases by 58.3% under 5.0% strain compared with the base asphalt. With the increase in filler content, the high-temperature and fatigue performance of asphalt increases first and then slows down, while the low-temperature stiffness rises gradually. Microscopic analysis indicates that the intercalation and strong adsorption of MMT restrict the light components of asphalt and increase the proportion of macromolecules, and FA plays the roles of particle filling and skeleton support. The two fillers synergistically optimize the colloid structure and molecular distribution of asphalt. Based on rheological properties and microscopic mechanism, the optimal ratio is 1:3 for MMT:FA with a total content of 5%, under which the composite modified asphalt achieves the best comprehensive pavement performance and can meet the requirements of heavy-load traffic and areas with large temperature differences. The research results can provide experimental and theoretical support for the material design, performance optimization and engineering application of MMT-FA composite modified asphalt. Full article

Pork is highly perishable during storage, leading to enormous economic losses and potential food safety hazards. Anthocyanins (ANTs) possess excellent antioxidant and antibacterial activities, but their poor stability in practical applications limits their industrial application. To address these issues, a novel composite preservation film was prepared by the four-sided applicator solution casting method, using polylactic acid (PLA) and polybutylene adipate-co-terephthalate (PBAT) as matrix materials and ANTs@ZIF-8 as functional filler. Zeolitic imidazolate framework-8 (ZIF-8) encapsulated ANTs to enhance its stability and achieve sustained release, while the PLA/PBAT was selected for its good biodegradability, mechanical and barrier properties. The structure and properties of the PLA/PBAT/ANTs@ZIF-8 composite films were investigated, and the results showed that ANTs@ZIF-8 nanoparticles had stable dispersibility in the matrix, which effectively improved the compatibility between nanoparticles and the film matrix. The prepared composite films exhibited excellent tensile strength (TS), elongation at break (EAB) and water vapor transmission rate (WVTR), as well as good antibacterial activity against E. coli and S. aureus. Furthermore, the practical pork preservation performance of the films was investigated, and the results demonstrated that the composite films could effectively reduce the pH value, water loss, color difference, total volatile basic nitrogen (TVB-N) content and malondialdehyde (MDA) content of fresh pork during storage, successfully extending the shelf life of pork to 12 days. This study develops a multifunctional, biosafe, and biodegradable PLA/PBAT composite film incorporated with ANTs@ZIF-8, providing a feasible strategy and scientific reference for the design and development of high-performance active biodegradable packaging materials. Full article

Ice formation and corrosion pose dual threats to critical infrastructure, such as power systems. Developing composite coatings that integrate efficient photothermal de-icing with long-term corrosion protection is of great value. In this study, a ternary synergistic hydrophobic coating was constructed utilizing multi-component fillers with complementary light absorption properties and multi-scale structures. The surface morphology, microstructure, optical absorption, wettability, ice delay behavior, photothermal de-icing performance, and corrosion resistance were systematically characterized using SEM, UV-Vis-NIR, AFM, contact angle goniometry, infrared thermography, and electrochemical analysis. The results demonstrate that the multi-component fillers construct unique multi-scale microstructures within the PDMS matrix. This architecture not only enhances surface hydrophobicity and delays ice nucleation but also delivers outstanding photothermal de-icing performance owing to its excellent broadband light absorption capability. Meanwhile, electrochemical tests reveal that the coating exhibits superior corrosion protection, reducing the corrosion current density by nearly four orders of magnitude compared to the unmodified substrate. This enhancement mechanism is primarily attributed to the ternary synergy among the fillers, which integrates complementary photothermal conversion, surface microstructuring, and corrosion barrier effects. This work provides a crucial strategy for developing novel coatings that integrate both anti-icing and anti-corrosion functionalities. Full article

Epoxy resin (EP) exhibits pronounced intrinsic brittleness arising from the highly crosslinked network formed after curing, thereby restricting its application in load-bearing structures. Although TiO₂ nanoparticles possess the potential for impact-strength improvement, they are highly prone to aggregation, which compromises stress-transfer efficiency within the composite. To overcome this challenge, a ball-milling strategy is adopted to anchor TiO₂ nanoparticles onto three-dimensional graphene oxide (3DGO), leading to the successful fabrication of a 3DGO@TiO₂ hybrid filler. At an ultralow loading of 0.03 wt%, the 3DGO@TiO₂ epoxy resin composite shows a 221.5% increase in impact strength to 19.55 kJ/m² and 33.53% and 32.34% increases in tensile and flexural strength to 64.32 MPa and 96.17 MPa, respectively, relative to neat EP. Morphological analyses indicate that the 3DGO spatial confinement reduces TiO₂ aggregate characteristic length by 55.1% from 1123 nm to 504 nm. Molecular dynamics simulations show that the hybrid filler decreases fractional free volume to 17.6%, induces denser matrix packing, and increases the calculated physical interfacial energy to 1023 kcal/mol, which is 2.2 times that of the pure TiO₂ epoxy resin system. This work confirms that 3DGO simultaneously optimizes nanofiller dispersion and physical confinement, offering a novel strategy for high-performance epoxy composites at ultralow loadings. Full article

This study presents, for the first time, an assessment of the dual role of waste enamels from heating device production in asphalt mixtures, as additives to modify euro bitumen (50/70) and as fillers, with a detailed analysis of their influence on properties of asphalt mixtures. Three types of enamels were investigated—premix (WEP), classic (WETM), and acid-resistant (WEART). Different characterization methods confirmed that these materials possess a borosilicate matrix enriched with various elements, including heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn). Although classified as hazardous by-products, enamels replaced 100% of conventional stone dust filler, with confirmed leaching test. Their role in bitumen modification was interpreted through a structure–property approach: bitumen (4–6 wt.%) acts as a viscoelastic polymer-like matrix, while enamel particles serve as micro-scale reinforcements that govern binder–filler interactions. The results demonstrate that, despite their hazardous nature, waste enamels are compatible with asphalt technology containing 5 wt.% bitumen, achieving satisfactory stability, acceptable deformation response, and favorable volumetric characteristics. By valorizing industrial waste in this novel way, this study opens a sustainable pathway for transforming hazardous materials into functional components for the asphalt industry. Full article

The escalating environmental concerns associated with the non-renewable nature of petrochemical-based composite constituents have accelerated the development of sustainable and renewable alternatives. This study evaluates the potential of woven hemp-reinforced polyfurfuryl alcohol (PFA, furan) composites as fully bio-based composite materials. The use of PFA, a fully bio-based resin renowned for its high rigidity and fire-retardant properties, has been hindered by challenges associated with water vapour evolution, acid-catalysed fibre degradation, and porosity formation. Novel woven long hemp fibres were combined with a polyfurfuryl alcohol resin formulated with a mild acid catalyst, while an early-stage venting procedure during compression moulding was investigated to mitigate porosity and fibre degradation. Thermogravimetric analysis was used to determine the venting moments during the moulding cycle. Despite the limited improvement in porosity reduction achieved through the investigated venting strategy, the hemp balanced satin 6/6 fabric–furan composites exhibited commendable stiffness with a maximum modulus of 17.0 ± 0.4 GPa. However, the inherent brittleness of the resin and possibly the presence of fire-retardant fillers limited the tensile strength (a maximum of 71.8 ± 4.2 MPa) and failure strain (a maximum of 0.72 ± 0.07%). The bending properties of neat furan resin produced using an improved curing protocol were comparable to those of conventional thermoset resins, with a modulus of 3.2 ± 0.2 GPa, strength of 110.5 ± 17.3 MPa, and failure strain of 4.1 ± 0.8%. Although several challenges remain, this study demonstrates the potential of natural fibre–furan composites for high-performance natural fibre composite applications and provides guidance for their further development. Future research should focus on optimising venting strategies, avoiding fire retardants to minimise resin brittleness, incorporating matrix tougheners, and enhancing the inherent toughness of the matrix. Full article

(Fe/C)/ABS resin electromagnetic metamaterials were fabricated via 3D printing, and the effect of iron salt loading (0, 1, 2, and 3 g) in the Fe/C filler on the microwave absorption performance of the resulting composites was systematically investigated. The results demonstrate that, with increasing iron salt content, the microwave absorption bandwidth of the samples exhibits a trend of initial significant broadening followed by saturation. At an iron salt loading of 1 g, the (Fe/C)/ABS resin composite achieves an effective absorption bandwidth (EAB) of 6.2 GHz at a matching thickness of 10 mm, representing an approximately 48% enhancement over that of the pure C/ABS resin composite (4.2 GHz). The incorporation of iron salts not only endows the material with magnetic loss capability but also promotes the formation of an sp²-hybridized carbon framework within the carbon matrix during Fe/C composite preparation, concurrently introducing abundant defect sites that augment the dielectric loss capacity. Under the synergistic magneto-dielectric loss mechanism, the microwave attenuation coefficient of the material is markedly enhanced, and the effective absorption bandwidth is substantially broadened, all at a filler loading of merely 2.5 wt%. This study elucidates the influence of iron salt loading on the microwave absorption performance of (Fe/C)/ABS resin composites, while the 3D printing-based fabrication approach employed herein offers a promising technical pathway for the development of novel microwave-absorbing materials. Full article

Background: Tooth root caries and periodontal tissue loss remain major challenges in elderly and periodontally compromised patients, while current restorative materials lack combined antibacterial and regenerative properties. Objective: The objective of this study was to develop a novel metformin-containing antibacterial composite for root cavity restorations to prevent recurrent caries and potentially promote periodontal tissue regeneration. Methods: Experimental composites contained 5% dimethylaminohexadecyl methacrylate (DMAHDM), varying metformin concentrations (2.5–15%), and glass fillers. Mechanical and antibacterial properties as well as cytocompatibility toward human periodontal ligament stem cells (hPDLSCs) were investigated. Results: The experimental composites achieved flexural strengths of 67.9 to 50.1 MPa (n = 6), significantly higher than (41.3 ± 3.4 MPa) of commercial control Vitremer (p < 0.05), while maintaining clinically acceptable elastic moduli of 3.7–3.1 GPa. Experimental composites achieved an 8-log reduction in Streptococcus mutans (S. mutans) biofilms and significantly reduced lactic acid production and metabolic activity compared to biofilms on commercial controls. The composite containing 15% metformin demonstrated acceptable cytocompatibility toward hPDLSCs under clinically relevant diluted conditions, matching commercial controls (p > 0.1). Conclusions: These findings suggest that this novel composite possesses potent antibacterial activity, acceptable cytocompatibility, and adequate mechanical properties, making it promising for multifunctional root caries restorations. Full article

Chlorogenic acid (CA) is an important natural antioxidant component and holds strong potential for health food and cosmetic applications. In this study, a silica-based photo-responsive molecular imprinting material (PMI-PDA@NH₂-SiO₂) was designed as a solid-phase extraction (SPE) adsorption filler and applied for the efficient separation of CA in Ficus carica L. Using polydopamine-modified NH₂-SiO₂ silica as the base, combined with the photo-responsive monomer 4-methacryloyloxyazobenzene (AZO-MAA), a molecular imprinting layer with photo-responsive regulation function was constructed. Under 365 nm ultraviolet light irradiation, the azobenzene group was isomerized to the cis structure, causing the imprint cavity to shrink, thereby enabling controlled release of CA, with complete desorption within 40 min, and a desorption rate of 94.33%. Importantly, the material retained 85.56% of its initial adsorption capacity and 91.38% of its original desorption efficiency after 6 consecutive adsorption/desorption cycles, confirming robust operational stability and reproducibility. PMI-PDA@NH₂-SiO₂ was applied to the extract of Ficus carica L., achieving an adsorption rate of 92.3% for CA and a desorption rate of 87.27%. Density functional theory (DFT) calculations and NOESY spectroscopic analyses revealed that CA interacted with functional monomers via hydrogen bonding and van der Waals forces. This study advances a green separation strategy for bioactive phytochemicals in complex natural matrices. Full article

Effective thermal management is critical for ensuring the reliability of modern high-power electronic devices, where thermal interface materials (TIMs) play key roles in minimizing contact resistance and improving heat dissipation. Boron nitride (BN) is widely used as a thermally conductive filler due to its high in-plane thermal conductivity and electrical insulation. However, achieving BN-based polymer composites that simultaneously offer high filler loading, flexibility, and high thermal conductivity (κ) remains a significant challenge. In this work, we introduce a novel two-step fabrication strategy to overcome this limitation. First, continuous BN fibers with high aspect ratios are assembled into BN fiber papers with enhanced fiber alignment. These papers are then cut and integrated into a silicone matrix to form well-oriented thermal conductive channels. This approach enables a significantly higher filler mass fraction of 70%, resulting in a thermal pad with a high κ of 19.23 W/(m·K), low thermal resistance of 1.61 cm²·K/W, and excellent electrical insulation and flexibility. Application tests further demonstrate superior heat dissipation performance and operational stability compared to commercial silicone pads. This work not only highlights the potential of BN fiber-based TIMs but also offers a feasible process for their large-scale manufacturing. Full article