Search Results (1,132)

Background: Polymeric drug-eluting films are promising platforms for local antibacterial delivery, but their release profiles depend strongly on the permeability and morphology of the barrier layer. Here, the previously proposed concept of additively manufactured PLACE (Printed Layered Adjustable Cargo Encapsulation) coatings was extended from "single orifice"-defined release toward porosity-assisted barrier control. Two conventional water-soluble porogens, polyethylene glycol (PEG) and polyvinylpyrrolidone (PVP), were compared with poly(2-ethyl-2-oxazoline) (PEOx), a hydrophilic polymer proposed as an alternative to PEG in biomedical formulations, but whose use as a leachable porogen has received little attention. Methods: Each porogen was introduced into the upper PLGA barrier of multilayer PLACE films. The resulting films were characterized for film formation, post-hydration morphology by SEM, release of methylene blue and vancomycin, and antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). Results/Conclusions: PEG was poorly compatible with PLGA and mainly produced surface-localized defects rather than a barrier with controlled permeability suitable for prolonged delivery. PVP K17 provided sustained release at 10 wt.%, whereas 20 wt.% PVP caused burst-dominated release and stronger morphological disruption. PEOx formed developed porosity at lower loading and produced release regimes ranging from several days to approximately two weeks. Vancomycin-loaded films containing 5 wt.% PEOx enabled near-complete release over two weeks while preserving film integrity and showed pronounced early anti-MRSA activity. These results identify porogen selection as a key formulation step and support PEOx as a useful porogen for early high-output antibacterial PLACE coatings. Full article

Oily wastewater, especially stable oil-in-water (O/W) emulsions, threatens aquatic ecosystems and is difficult to treat using conventional separation technologies. Herein, a hydrophilic and underwater oleophobic chitosan/polyvinyl alcohol (PVA)/cellulose aerogel (CPCG) was fabricated through a facile one-pot dip-coating strategy. Cellulose aerogel (CG) was prepared by low-temperature dissolution, network reinforcement, washing, and freeze-drying, before being coated with a cross-linked CS/PVA layer using glutaraldehyde, followed by NaOH solidification. SEM revealed a honeycomb-like cellulose framework uniformly covered by the CS/PVA coating, which improved the structural integrity of the skeleton. FT-IR and TG analyses supported the successful construction of the coating and the enhanced thermal stability of CPCG. CPCG displayed a high underwater oil contact angle of 153.8°, which remained above 153° after 30 min, indicating robust underwater oil repellency. Wet CPCG retained 99% of its original height after 30 compression–recovery cycles. Owing to the stable hydration layer, interconnected channels, and improved wet-state resilience, CPCG efficiently separated light and heavy oil/water mixtures and various O/W emulsions. The separation efficiencies for different emulsions were above 99%, and CPCG retained about 93% efficiency after ten cyclohexane/water emulsion separation cycles. This work provides a green and scalable route for constructing biomass-based aerogels for oily wastewater treatment. Full article

The interfacial behavior of hybrid nanoparticles on biological substrates governs their functional performance. Here, we investigate how surface properties and colloidal stability dictate the pH-dependent adhesion of oxybenzone-loaded palygorskite nanohybrids to hair—a model biological interface. A series of hybrids with 5–50% oxybenzone loadings were prepared via melt impregnation. XRD and FTIR analyses confirm hydrogen bonding between oxybenzone and palygorskite, forming stable organic–inorganic hybrids. The colloidal stability of these nanohybrids varies non-monotonically with oxybenzone loading, governed by surface hydrophilicity and zeta potential, exhibiting a network-like behavior upon pH change. Optimal stability is achieved at an intermediate loading with a favorable balance of surface properties. While pristine hybrids show no affinity for hair, surface modification with cationic polyquaternium-7 (PQ-7) or non-ionic polyvinylpyrrolidone (PVP) enables effective deposition through distinct pH-dependent mechanisms: PQ-7 operates optimally at pH 10 via electrostatic attraction, whereas PVP performs best at pH 4 through hydrogen bonding, forming a protective coating layer on the hair surface. Deposition fails for PVP-modified hybrids at 50% loading due to excessive surface hydrophobicity. The deposited hybrids provide exceptional UV protection, significantly mitigating cuticle damage, suppressing photo-yellowing, and minimizing protein oxidation. Among the hybrids, hybrid-35 exhibited the best colloidal stability, whereas PQ-7-modified hybrid-50 gave the highest UV protection (color difference ΔE reduced from 10.51 to 1.60). The adhesion rates of the two best-performing hybrids were 2.70% and 2.85%, respectively. Beyond hair protection, we evaluate the environmental interface of these materials. While free oxybenzone is highly toxic to Chlorella vulgaris, hybridization drastically reduces its ecotoxicity. Remarkably, palygorskite and the hybrids promote algal growth, likely by acting as nutrient adsorbents and attachment sites. This work provides fundamental insights into particle–biointerface interactions and offers a strategy for designing functional hybrid materials with tailored surface properties for bio-related applications. Full article

Polylactic acid (PLA) is a promising biopolymer for environmentally friendly coating development. However, its UV radiation resistance has not yet been sufficiently studied, particularly in formulations containing plasticizers or fillers. In this study, a series of samples were prepared: pure PLA films, PLA films with plasticizers, filled composites, and films obtained from aqueous PLA dispersions. The samples were tested for UV resistance and characterized using FTIR spectroscopy, surface energy analysis, and topography. The results showed that UV irradiation of pure PLA caused carbonyl band broadening and a shift toward lower wavenumbers, water contact angle decrease and surface energy polar component increase. The effect of plasticizers was chemical composition-dependent; epoxy linoleic acid increased the degradation rate, whereas PEG-400 and menthol oleic acid reduced the carbonyl groups accumulation. Menthol oleic acid demonstrated the strongest stabilizing effect. The calcite and kaolin fillers promoted surface oxidation and hydrophilization, while coffee grounds biochar reduced the degradation rate. Films obtained from aqueous dispersions were the most sensitive to UV aging, as residual emulsifier significantly enhanced surface hydrophilization. Full article

The development of advanced and efficient oil–water separation technologies is crucial, and membrane fouling remains one of the primary obstacles hindering the sustainable development of membrane technology. Separation membranes, which differ in pore size and material composition, can be selected based on specific environmental conditions and application requirements. In the study, a composite enhanced PVDF membrane with a complex coordination aggregation structure and abundant hydroxyl groups was prepared by introducing a citric acid–Fe(III) complex coating onto the PVDF surface using tannic acid as an interfacial adhesive layer. Citric acid (CA) molecules participate in competitive cross-linking. The carboxylic acid groups (-COOH) of CA form ionic bonds with Fe³⁺. This promotes the formation of a complex cross-linked network inside the coating. It also successfully introduces additional hydrophilic groups. Consequently, a TA-Fe/CA composite coating system is constructed. The optimized modified membrane exhibited superior performance, with a water contact angle (WCA) of 14° and complete wetting within 0.5 s. The pure water flux reached 20,473.16 L/m²·h. Compared to the pristine membrane, the modified membrane demonstrated significantly enhanced hydrophilicity, underwater oleophobicity, and antifouling properties. During the separation of surfactant-stabilized toluene emulsions, the PVDF-TA-Fe/CA membrane showed higher separation efficiency and permeate flux than both the PVDF and PVDF-TA membranes. Furthermore, the modified membrane demonstrated excellent chemical stability, long-term durability, and thermal stability. Full article

We report di- and triblock copolymers that combine hydrophilic polyethers—poly(ethylene glycol) monomethyl ether (mPEG) and polyglycidol (PGl)—with a hydrophobic, degradable polyester, poly(β-butyrolactone) (P(β-BL)). A mild hydrolysis method was developed to selectively remove acetal protecting groups from poly(ethoxy ethyl glycidyl ether) (PEEGE) without cleaving the β-butyrolactone polyester backbone, enabling the preparation of PGl-b-P(β-BL) and mPEG-b-PGl-b-P(β-BL) block copolymers. Thermal analysis revealed that the glass transition temperatures (T_g) of the copolymers could be tuned by varying block composition and length. Diblock copolymers containing the PGl segment were amorphous, with T_g values ranging from −2.7 to −19.9 °C. The presence of an mPEG segment in the triblock copolymers resulted in a further decrease in T_g, reaching values between −32.3 and −38.9 °C. Solubility and water affinity studies demonstrated that incorporation of hydrophilic polyether blocks enhances copolymer–solvent interactions, leading to increased wettability of the polymer-coated surface. The water contact angle for films formed from PGl-b-P(β-BL) decreased to 53 °C, while for mPEG-b-PGl-b-P(β-BL) copolymers, it was further reduced to 43 °C compared with the hydrophobic P(β-BL) film. Hydrolytic degradation experiments showed accelerated cleavage of the P(β-BL) segment in copolymers containing hydrophilic blocks compared to the P(β-BL) homopolymer, which is attributed to increased water accessibility and surface hydrophilicity. The most pronounced decrease in molar mass, reaching at least 50% relative to the initial non-degraded sample, was observed for the diblock copolymers, whereas the P(β-BL) sample showed only a marginal weight reduction of a few percent. Overall, this study demonstrates that the combination of hydrophilic mPEG and PGl blocks with P(β-BL) enables the design of block copolymers with tunable thermal properties, solubility, and degradation behavior, offering potential for a wide range of applications. Full article

This study investigates the damage behavior and surface integrity of chitosan–nanohydroxyapatite (CS/nHAp) composite coatings, along with their corrosion resistance and wettability, which directly affect their biological performance in vivo. The coatings were deposited on Ti13Zr13Nb and stainless steel using electrophoretic deposition (EPD) at various voltages and deposition times. Surface topography, morphology, composition, and roughness were characterized using microscopic techniques, while wettability, corrosion resistance, and mechanical properties were assessed. Three-point bending tests were performed to determine coating behavior under mechanical deformation. Hydrophilic, homogeneous CS/nHAp coatings were successfully deposited without visible cracks on the surface. Coatings deposited at 10 V exhibited higher corrosion potentials compared to uncoated titanium alloy. Mechanical testing showed that coatings deposited at 10 V were significantly harder than those deposited at 20 V. The CS/nHAp20_5 coating exhibited moderate hardness (0.33 ± 0.06 GPa), the lowest Young’s modulus (12.7 ± 1.4 GPa), increased flexibility, and good adhesion, without delamination during bending tests. These results demonstrate that by modifying deposition parameters, it is possible to adjust the mechanical and protective properties of CS/nHAp coatings for potential application of the developed coating in vascular stents. Full article

In this study, a functional surface coating composed of Fe-Mn binary oxide (FM) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS, PP) was applied to a PVDF membrane (PP-FM-PVDF) for efficient arsenate (As(V)) removal. PP acts as a dispersant and hydrophilic modifier, ensuring uniform FM distribution and reducing the water contact angle to 50.1°. The PP-FM-PVDF membrane achieves a maximum As(V) adsorption capacity of 30.43 mg/g, outperforming pristine and singly modified membranes. The batch adsorption data fit the Langmuir isotherm (R² = 0.999) and pseudo-second-order kinetic model (R² = 0.99), indicating monolayer chemisorption. The coating increases the specific surface area to 27.33 m²/g and the tensile strength to 6.41 MPa. Dynamic filtration shows that 2.70 L (2149.7 L/m²) of 100 μg/L As(V) solution can be treated before the permeate concentration exceeds the WHO guideline of 10 μg/L. After alkaline regeneration (pH 11), 62.9% of the initial capacity is retained. Complementary surface-sensitive analyses (zeta potential, XPS, and EXAFS) reveal that arsenate adsorption occurs primarily through ligand exchange between arsenate oxyanions and Fe/Mn surface hydroxyl groups on the coating, forming inner-sphere bidentate complexes (Fe–O–As and Mn–O–As), while electrostatic interactions play a secondary, pH-dependent role. This surface engineering strategy—synergistically integrating a conductive hydrophilic polymer with a metal oxide as a functional coating on PVDF—offers a reusable, high-performance platform for arsenate remediation, underscoring the critical role of interface design in environmental membrane applications. Full article

Cotton fabrics are widely used due to their comfort and biodegradability; however, their intrinsic hydrophilicity limits their performance in advanced applications. In this work, a fluorine-free approach for imparting durable hydrophobicity to cotton was developed based on thiol-ene crosslinking of polysiloxane networks formed on the fiber surface. Two thiol-functional polysiloxanes differing in –SH group content were combined with four vinyl-functional organosilicon crosslinkers under UV (2,2-dimethoxy-2-phenylacetophenone (DMPA)) and thermal (2,2′-azobis(2-methylpropionitrile) (AIBN)) initiation. FT-IR analysis confirmed the presence of siloxane structures, while SEM-EDS revealed stable silicon- and sulfur-containing layers. SEM observations showed continuous coatings without blocking the textile structure. Water contact angle (WCA) measurements demonstrated that hydrophobic performance strongly depends on thiol content and crosslinker structure, with the highest values obtained for the thiol-rich polysiloxane and tetrafunctional vinyl crosslinker. All modified fabrics exhibited high durability, with minimal changes in WCA and complete droplet stability (1800 s) after washing. In the case of the lower-functionality polysiloxane, an increase in hydrophobicity after washing was observed, attributed to the reorganization of siloxane chains. These results demonstrate that thiol-ene crosslinking provides an effective strategy for designing durable, fluorine-free hydrophobic coatings on cotton. Full article

The expired drug Detralex (90% diosmin and 10% hesperidin), known as an effective corrosion inhibitor, was adsorbed onto mesoporous silica and incorporated into an epoxy matrix to enhance the coating’s corrosion protection in a highly corrosive 3 wt% NaCl solution. It was found that this treatment, by improving adhesion, modifying the hydrophilic properties, and enabling inhibitor release, increased the coating’s resistance over time. Based on an SEM-EDX analysis, even after 24 h of immersion, the epoxy coating with mesoporous nanosilica adsorbed with diosmin and hesperidin retained the incorporated inhibitors. This resulted in a slight increase in the samples’ polarization resistance during longer exposure. Full article

We present an optimized method for producing semiconducting polymer dots using a water–ethanol mixed antisolvent during nanoprecipitation. Compared to conventional Pdots made with pure water as the antisolvent, these newly produced Pdots exhibit simultaneously enhanced fluorescence efficiency and stability of particle size and emission spectra. These findings should be mainly attributed to an improved core–shell Pdots nanostructure formed by a sequential nanoprecipitation process. It offers Pdots a purer, more compact, and hydrophobic inner core, coated with a greater number of hydrophilic polyethylene glycol shells. This viewpoint is further reinforced by Förster energy-transfer efficiency in a fluorescence donor-acceptor Pdots system. The novelly prepared Pdots can better encapsulate small-molecular cargoes and more efficiently bioconjugate to targets. Consequently, it demonstrates improved specific immunofluorescence staining of microtubule structures in living cells. Full article

Efficient separation of Cu–Mo sulfide minerals from moraine materials remains a major challenge for low-grade, high-moraine Cu–Mo ores. Fine-grained muscovite induces severe slime coating and gangue entrainment, thereby markedly reducing flotation selectivity. In this work, a biodegradable polymer depressant, polyaspartic acid (PASP), was employed to regulate Cu–Mo sulfide flotation under muscovite interference conditions. Microflotation tests, particle size distribution analysis, zeta potential measurements, SEM-EDS observations, contact angle measurements, and XPS analyses were conducted to clarify the dispersion behavior, slime-coating mechanism, and selective adsorption characteristics of PASP. The results demonstrated that PASP selectively depressed muscovite at relatively low dosages while exerting negligible influence on the floatability of chalcopyrite and molybdenite. Notably, at a dosage of 15 mg/L, PASP reduced muscovite recovery by 43.07% and 31.23% more effectively than sodium silicate and sodium hexametaphosphate, respectively, demonstrating superior selective depression efficiency under moraine interference conditions. Particle size distribution and zeta potential analyses confirmed that PASP effectively weakened heterocoagulation and electrostatic attraction between muscovite and sulfide minerals, thereby suppressing slime coating and improving slurry dispersion stability. SEM-EDS and contact angle analyses further revealed that PASP significantly reduced muscovite deposition on sulfide mineral surfaces while maintaining the hydrophobicity of chalcopyrite and molybdenite. High-resolution XPS analysis further indicated that PASP adsorbed onto muscovite mainly through coordination between carboxylate groups and surface Al–OH sites, forming a stable hydrophilic adsorption layer. Overall, PASP provides a low-dosage, highly selective, and biodegradable depressant strategy for mitigating muscovite-induced slime coating and improving the flotation separation of Cu–Mo sulfide ores under moraine interference conditions. Full article

Nanotextured thin film metallic glasses (TFMGs) have emerged as promising antimicrobial coatings for biomedical applications; however, systematic comparisons across compositionally distinct Ti- and Zr-based systems, as well as their early-stage bactericidal mechanisms, remain limited. Here, we show, for the first time, a comparative, compositionally resolved correlation linking alloy chemistry, nanotexture, and bactericidal mechanisms across polymorphic TFMGs. Three co-sputtered biocompatible coatings (Ti₄₇Fe₄₁Cu₁₂, Zr₇₁Fe₃Al₂₆, and Zr₅₈W₃₁Cu₁₁) were deposited on medical-grade titanium and stainless steel (SS316L) via magnetron co-sputtering, producing uniform amorphous films (190–298 nm) with nanoscale roughness of 1.6 ± 0.05 to 8.1 ± 0.05 nm. Surface wettability spanned hydrophilic (71.1 ± 5.6°) to hydrophobic (106.5 ± 3.5°), modulating bacterial interactions. Antimicrobial performance against Pseudomonas aeruginosa was evaluated using live/dead fluorescence imaging, quantitative image analysis, and electron microscopy after 2–4 h incubation. All coatings reduced bacterial adhesion and viability relative to bare substrates, with Zr₅₈W₃₁Cu₁₁ achieving >60% reduction in surface-associated bacterial coverage. Time-resolved analysis revealed a rapid transition to predominantly non-viable populations on coated surfaces, in contrast to sustained viability on controls. Mechanistically, bactericidal activity arises from the synergistic coupling of nanotopography-induced membrane stress, wettability-governed adhesion energetics, and in situ formation of CuO, Fe₂O₃, WO₃, and ZrO₂ oxides that promote electrostatic interactions and proposed reactive oxygen species generation, driving oxidative membrane damage. These results establish a scalable design framework for TFMGs, while highlighting the need for long-term biofilm and electrochemical validation. Full article

Bone grafting remains limited, and the strategies to design even more structurally complex scaffolds—able to reproduce the hierarchical architecture of bone extracellular matrix—are rapidly growing. In this study, we report the fabrication of a hierarchically structured scaffold produced by layering poly(ε-caprolactone)/gelatin (PCL/Gt) or poly(lactic acid)/gelatin (PLA/Gt) electrospun nanofibers via coaxial electrospinning onto 3D-printed poly(lactic acid) (PLA) scaffolds via fused deposition modeling (FDM). After the printing process, PLA disks (10 × 1 mm, 20% infill, ~80% porosity, pore size ~1.57 mm) were coated with core/shell (PCL/Gt, PLA/Gt) fibers to investigate the in vitro interfacial response of osteoblasts in comparison with monocomponent fibrous coatings (PCL, PLA, Gt). SEM and TEM confirmed that core/shell fibers exhibited bead-free morphologies, with a significant reduction in fiber diameter (≈287–316 nm) and higher interfibrillar porosity compared to monocomponent fibers. FTIR and thermogravimetric analyses indicated the presence of hydrogen bonding between the polyester and gelatin, and the absence of residual solvent after deposition. At the same time, water contact angle measurements confirmed an increase in hydrophilic properties from 80–86° to 120° ascribable to the presence of gelatin. Accordingly, in vitro response of human fetal osteoblasts (hFOB 1.19) exhibited an evident improvement in the case of Gt-based fibrous coatings (i.e., PCL/Gt and PLA/Gt) in terms of early adhesion (4–24 h) and metabolic activity from 3 to 21 days, cell spreading into star-shaped morphologies, formation of extracellular matrix, and mineral phase deposition. In more detail, a remarkable increase in alkaline phosphatase activity was observed in Gt-based coaxial coatings from day 7 onward, with the highest values recorded for PLA/Gt. Overall, we demonstrated that the Gt-based coaxial fibrous coating provided a mix of topological and biochemical cues that synergistically promoted key osteoblast activities at the interface, supporting the regeneration of new bone tissue in highly tailored 3D-printed scaffolds, thus suggesting a promising strategy for personalized regenerative medicine. Full article

This study systematically investigated flow boiling characteristics within a novel three-layer microchannel heat sink with 3/4 open-ring pin fin arrays, designed for high-heat-flux thermal management of low-carbon metallurgical reactors. Two-phase flow regimes, pressure drop, and wall temperature responses were analyzed. To evaluate the impact of functional surface material properties on thermo-hydraulic behavior, a hydrophilic nano-coating modification was applied to the inner copper channel walls for comparison. Increasing the flow rate triggered a transition from a vapor-dominated confined slug flow to a liquid-dominated dispersed bubble flow, which effectively improved the thermo-hydraulic stability. Hydrophilic surface modification resulted in an average pressure drop reduction of 33% and significantly diminished the sensitivity of flow resistance to velocity variations. Through hydrophilic treatment, the localized vapor film effect at high velocities was suppressed, and temperature field homogenization was promoted, yielding a maximum convective heat transfer coefficient of 7760 W/(m²·°C), i.e., 72.9% enhancement over the baseline heat sink. The underlying mechanism is attributed to the formation of a stable near-wall thin liquid film and the promotion of high-frequency nucleate boiling. These results will be of high relevance for developing efficient cooling solutions for power electronics, thereby supporting the advancement of low-carbon metallurgical reactors. Full article