Search Results (82)

Conventional polydimethylsiloxane (PDMS)-based antifouling coatings, despite their inherent fouling-release capability, exhibit critically insufficient antifouling performance under static seawater conditions. Inspired by the synergistic physical–chemical defense strategy of sessile marine organisms, specifically sea anemones, which combine a physical mucus barrier with antimicrobial peptide secretion, the present work develops a multi-mechanism hybrid coating—designated as sea anemone-inspired fluorosilicone polyurethane—that integrates low-surface-energy physical antifouling and cationic antibacterial chemical antifouling. This coating system is constructed from silicone polyurethane (PDMS-PU), a cationic antibacterial moiety (PDMS-N⁺), and fluorinated functional monomers. Through systematic compositional optimization, an optimal formulation (P-4) is identified, which achieves a fracture elongation of 78.19%, a normal adhesion strength of approximately 2.5 MPa, a water contact angle of 120°, and a surface energy of 12.86 mN/m. Notably, its antibacterial rates against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) exceed 95%. The resultant coating uniquely synergizes low surface energy, potent antibacterial activity, excellent mechanical properties, and thermal stability, thereby enabling long-term and stable antifouling performance in static seawater environments. This work provides a crucial technological foundation for the engineering application and industrialization of green, durable marine antifouling coatings. Full article

This study analyzes a low-cost potassium feldspar mineral from Chihuahua, Mexico, for removing cationic dyes (methylene blue and rhodamine 6G) from water. The raw mineral, characterized by Rietveld refinement as a polymineralic composite of sanidine (49 vol%), muscovite (27 vol%), calcite (16 vol%), and anorthoclase (7 vol%), demonstrated significant dual functionality. In darkness, it acted as an effective adsorbent, achieving 98% and 76% removal of MB and R6G, respectively, after 120 min, with adsorption behavior fitting the Langmuir isotherm. Under solar irradiation, the mineral facilitated photocatalytic degradation, evidenced by a faster intensity decrease and a shift in the absorption bands, and the near-complete decolorization of the dyes. The degradation kinetics were significantly accelerated in a synergistic advanced oxidation process (AOP) with added hydrogen peroxide (H₂O₂), achieving 98% degradation for MB and 93% degradation for R6G within 15 min, compared with 97% for MB and 65% for R6G under sunlight irradiation alone. Kinetic analysis revealed that the process consistently followed a pseudo-second-order model, indicating a surface-controlled mechanism dependent on dye concentration and the availability of active sites. Additional fitting with the Elovich and Avrami models suggested heterogeneous surface behavior and multistep degradation pathways, implying that the overall process involved concurrent adsorption, surface-mediated catalytic reactions, and oxidative degradation driven by photogenerated reactive species. Additionally, the scavenger tests revealed that the dominant reactive species depended on the presence of ${\mathrm{H}}_2{\mathrm{O}}_2$: ${\mathrm{O}}_2^{•-}$ radicals prevailed in the peroxide-free system, whereas $•\mathrm{OH}$ radicals dominated under ${\mathrm{H}}_2{\mathrm{O}}_2$- assisted conditions. Photoluminescence spectroscopy analysis provided mechanistic insights, tracking the evolution of dye monomers, dimers, and aggregates, confirming structural degradation of the dyes and revealing the formation of specific fluorescent intermediates. Together, these findings highlight the mineral’s potential as an abundant, eco-friendly material for solar-driven wastewater treatment. Full article

This study addresses a critical challenge in surface engineering: developing robust nanocomposite layers on high-performance thermoplastics without inducing macroscopic thermal degradation. While cold gas dynamic spraying (CGDS) of polymers is often described in the literature as a deposition process based on purely mechanical anchoring of particles into polymer surface, our work establishes a multi-scale, hybrid physical–chemical adhesion framework. Using a coupled 3D thermoplasticity finite element model with a Mie–Grüneisen equation of state and Johnson–Cook criteria, we evaluate the supersonic impact dynamics ($V_0=1000 \mathrm{m}/\mathrm{s}$) of single-walled (5,0) CNTs impacting a PEEK substrate at oblique angles (0–20°). The core scientific lies in bridging continuum mechanics with quantum-chemical statistics. By applying Weibull weakest-link theory to a 37-bond monomer model, we demonstrate that compliant $C_{arom}-O$ ether bonds selectively absorb impact energy, covering 8.37% of their dissociation barrier. This non-uniform energy sharing yields a 0.23% monomer activation probability, generating a high free-radical density of ~1100 ${\mathrm{\mu }\mathrm{m}}^{-2}$ beneath the particle plume. This localized “chemical nano-welding” network provides exceptional chemical adhesion, while the remaining 99.77% of intact chains ensure structural rigidity, reinforced by a mechanical “self-locking” field (residual compressive stresses up to 0.9 GPa). This study provides a scientific foundation for designing functional coatings tailored for engineering, aerospace, and biomedical applications. Full article

Cuticular wax metabolites on leaf surfaces function as chemical interfaces that modulate the pre-penetration development of phytopathogenic fungi. However, the specific monomeric constituents in grapevine leaf wax that regulate conidial germination and host recognition by grapevine powdery mildew caused by Erysiphe necator remain elusive. Here, we compared leaf cuticular wax characteristics between four susceptible Vitis vinifera cultivars and three resistant Chinese wild Vitis accessions. Scanning electron microscopy coupled with gravimetric analysis revealed that susceptible V. vinifera cultivars exhibited lower wax loads and lamellar crystals, whereas resistant Chinese wild Vitis accessions displayed higher wax accumulation with granular or blocky crystals. Gas chromatography–mass spectrometry profiling further demonstrated divergent compositional patterns: primary alcohols predominated among susceptible V. vinifera cultivars, while aldehydes and alkanes were enriched in resistant Chinese wild Vitis accessions. Paradoxically, in vitro conidial germination assays showed that wax extracts from all grapevines significantly promoted En. NAFU1 conidial germination, indicating that resistance in Chinese wild Vitis accessions is independent of direct wax-mediated inhibition of spore germination. Bioassays of representative monomers revealed that n-triacontane suppressed germination at high concentrations, whereas n-dotriacontanol and stearic acid stimulated it. Collectively, these findings demonstrate that specific cuticular wax monomers exert distinct biological effects on En. NAFU1 conidial germination. Given the ubiquitous presence and concentration-dependent stimulatory activity of stearic acid, we hypothesize that this monomer serves as a conserved chemical cue enabling initial host recognition by En. NAFU1, whereas the differential susceptibility among grapevine genotypes is governed by downstream physical and induced defense mechanisms rather than by variation in stearic acid levels. Full article

Background/Objectives: Protein nanocages are versatile platforms with potential applications in drug delivery, enzyme encapsulation, and bioreactor systems, owing to their precise self-assembly and excellent biocompatibility. However, most protein cage systems have limited accessibility to their internal space, which hinders the efficient encapsulation of large molecules or complex proteins. Methods and results: In this study, we propose a programmable reassembly system by artificially splitting the monomer of lumazine synthase, a protein that naturally forms a nanocage through self-assembly. Using intein-mediated protein splicing, the self-assembly of the monomer was converted into a condition-dependent reaction, enabling the incorporation of large or functional biomolecules prior to the assembly stage. Furthermore, to achieve targeted delivery, an EGFR-binding affibody (EGFRAfb) was fused to the split monomer so that it is exposed on the cage surface after reassembly, thereby providing selective binding capability toward EGFR-expressing cells. Successfully reassembled nanocages were visualized, and the fluorescent proteins encapsulated within them were delivered to the target and activated in specific cells. Conclusions: Therefore, the programmable protein nanoplatform presented in this study can overcome the spatial limitations of conventional protein cages while allowing for precise control over both the timing of cage assembly and targeted molecular delivery. Full article

The increasing release of Cu(II) into aquatic environments has intensified the demand for efficient and selective removal strategies. Although adsorption is widely applied for Cu(II) removal, its performance is often constrained by limited accessibility and low selectivity of active sites. In this study, a hybrid ion-imprinted polymer was synthesised via a single-step grafting–imprinting–polymerisation (SGPI) strategy, enabling the formation of a surface-oriented imprinted polymer layer on a functionalised graphene oxide support (GO/MPS). 4-vinylpyridine (4VP) was employed as the functional monomer to promote specific Cu–N coordination and facilitate binding-site formation. The resulting GO/MPS@IIPs-Cu(II) achieved an adsorption capacity (Qmax) of 256 mg g⁻¹, together with faster adsorption kinetics relative to bulk IIPs-Cu(II). The material also demonstrated improved selectivity for Cu over competing ions (Co, Fe, and Ba), as well as satisfactory reusability, maintaining extraction efficiencies above 98% after eight adsorption–desorption cycles. These findings demonstrate that the SGPI strategy enables a more organised distribution of imprinted binding sites, thereby improving their accessibility and promoting a synergistic combination of high adsorption capacity, rapid kinetics, selectivity, and reusability. This approach establishes a robust platform for the development of advanced hybrid ion-imprinted polymers for the selective removal of metal ions. Full article

Modern wound care is challenged by the emergence of antibiotic-resistant bacterial strains, causing the need for advanced dressing materials that provide infection control while promoting healing. Although polyacrylamide (PAAm) hydrogels are widely investigated due to their biocompatibility, their lack of intrinsic antibacterial activity and poor mechanical properties restrict their clinical use. To overcome these limitations, this study proposes a natural–synthetic hydrogel that combines PAAm with TEMPO-oxidized cellulose nanofiber (TOCNF) functionalized silver nanoparticles (AgNPs). The synthesis is performed through the polymerization of the synthetic monomer in the presence of the TOCNF–AgNPs, the nanofibrillar cellulose simultaneously serving as a reducing and stabilizing agent for AgNPs, and as a plasticizer for the PAAm network. Morpho-structural analysis of the hybrid precursor (TOCNF–AgNPs) revealed two populations of AgNPs, offering a cumulative effect between rapid bacterial penetration and a prolonged ionic reservoir, while maintaining the stability of the system. The subsequent incorporation of the hybrid into PAAm matrix resulted in tunable swelling kinetics and mechanical properties. Wettability and surface stiffness improve with the increase in hybrid content. The antibacterial effect was confirmed by a colony-counting assay for formulations with higher AgNPs content, exhibiting inhibitory metabolic activity against several pathogenic strains. These results suggest that PAAm/TOCNF–AgNPs (PTA) nanocomposites represent a promising mechanically adaptive candidate for wound-care applications. Full article

Chiral polymeric nanoparticles derived from protected L/D-Phe-OMe- and unprotected L/D-Phe-based monomers were developed as functional chiral coatings for PVDF membranes to induce enantioselective recognition. The present study introduced a sonochemichal-assisted approach to the deposition of Phe-based polymeric nanoparticles onto PVDF membranes, generating chiral membrane surfaces that can facilitate enantioselective transport and crystallization. The enantioselective performance of the modified membranes was evaluated through membrane transport experiments using DL-leucine and a crystallization investigation with DL-tyrosine. Enantioselective transport experiments showed pronounced chiral resolution, achieving an enantiomeric excess (ee) of 79/76% for D/L-Leu. Furthermore, enantioselective crystallization was demonstrated using DL-tyrosine in the presence of L/D-Phe-OMe-coated membranes. Optical activity measurements, supported by SEM and DSC analysis, confirm membrane-induced enantiomeric enrichment yielding an ee of 60/68% for L/D-Tyr. These results highlight the potential of chiral polymer-coated PVDF membranes as versatile platforms for enantioselective separation. Full article

A hybrid material based on the copolymerization of EDOT (3,4-ethylenedioxythiophene) and Py (pyrrole), 1:1 monomer ratio, onto multi-walled carbon nanotubes (MWCNTs) was synthesized through a multistep functionalization approach. The resulting P(EDOT-co-Py)@MWCNT hybrid, poly(3,4-ethylenedioxythiophene-co-pyrrol)@MWCNT hybrid, was characterized by Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). These characterizations confirmed the successive functionalization steps, the effective anchoring of the monomers, and the subsequent formation of the copolymer. Transmission electron microscopy (TEM) images revealed a homogeneous polymer coating along the nanotube surface while preserving the structural integrity of the MWCNTs throughout the functionalization and polymerization processes. The P(EDOT-co-Py)@MWCNT hybrid was evaluated as an active electrode material for aluminum-ion storage in an aqueous aluminum sulfate electrolyte. The system exhibited two distinct charge-storage mechanisms: at high current densities, proton surface adsorption dominated, whereas at lower rates, a faradaic contribution associated with polymer chain redox activity and the reversible extraction/insertion of Al³⁺ became prevalent. The hybrid electrode delivered high specific capacities, reaching 200.6, 106.3, and 44.3 mAh g⁻¹ at 0.10, 0.25, and 0.50 A g⁻¹, respectively. These values are comparable to—or even exceed—those reported for similar cathodic materials designed for Al³⁺ storage, highlighting P(EDOT-co-Py)@MWCNT hybrid as a highly promising cathode candidate for aqueous aluminum-ion energy-storage systems. Full article

Poly(ethylene terephthalate) (PET) is a widely used commodity polymer owing to its low cost, excellent mechanical properties, and high processability. Chemical modification of PET surfaces to impart specific functionalities represents an effective strategy for transforming PET into high-value-added materials without altering its bulk properties. In this study, we investigated the surface functionalization of PET substrates using surface-initiated atom transfer radical polymerization (SI-ATRP). ATRP initiation sites were introduced onto PET surfaces through mild surface hydrolysis followed by polyethyleneimine coating. To further enhance the grafting density, an inimer-based strategy was employed, in which a bifunctional monomer containing both a polymerizable group and a latent initiation site was used to form hyperbranched polymer structures on the PET surface, thereby amplifying the number of active initiation sites. Using these modified PET substrates, SI-ATRP of functional methacrylate monomers was successfully carried out. Grafting of poly(2,2,2-trifluoroethyl methacrylate) imparted highly hydrophobic surface properties, yielding water contact angles above 120°, whereas grafting of poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) produced hydrophilic surfaces with contact angles below 20°. Surface characterization by X-ray photoelectron spectroscopy confirmed successful graft polymerization and effective surface coverage. While the macroscopic wettability was primarily governed by the chemical nature of the grafted polymers, the inimer-based initiation-site amplification significantly enhanced the surface electrostatic properties of the polycationic polymer–grafted surfaces, increasing the ζ-potential from approximately +20 mV to over +100 mV. Antibacterial tests using Escherichia coli K-12 as a model bacterium demonstrated that PET substrates grafted with poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) exhibited clear contact-active antibacterial activity, achieving up to 2-log reduction in viable bacterial counts after 3 h of contact incubation. These results highlight the importance of molecular-level control of grafting architecture and surface electrostatic properties in the design of functional antibacterial PET surfaces. Full article

Dental composite reconstructive materials (DCRMs) used in caries treatment possess satisfactory functional properties but lack antimicrobial activity, which may lead to secondary caries. This research aimed to modify the DCRM matrix with urethane-dimethacrylate monomers derived from cycloaliphatic and aromatic diisocyanates bearing quaternary ammonium groups. The diisocyanates used were 1,3-bis(1-isocyanato-1-methylethyl)benzene (TMXDI), isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4′-diisocyanate (CHMDI), and 1,1′-methylenebis(4-isocyanatobenzene) (MDI). As a result, eight modified copolymers were obtained and tested for the surface water contact angle (WCA), water sorption (WS), and water solubility (SL). The WCA results indicated predominantly hydrophilic surfaces, while the WS and SL values were generally satisfactory. Full article

This paper provides a systematic review of urushiol-based antibacterial coatings for lacquer art applications, focusing on three key dimensions: molecular mechanisms, durability, and safety. Natural lacquer films form a dense three-dimensional network through laccase-catalyzed oxidative cross-linking, endowing them with excellent mechanical properties and corrosion resistance, while the catechol structure in urushiol confers broad-spectrum antibacterial potential. The article elaborates on the synergistic antibacterial mechanisms of urushiol, including covalent reactions with bacterial proteins via quinone intermediates, induction of oxidative stress, and metal ion chelation. It also reveals the dynamic change pattern of coating antibacterial activity over time, characterized by “high initial efficiency- gradual mid-term decline—long-term stabilization,” a process influenced collectively by side-chain unsaturation, degree of curing, and environmental factors such as temperature, humidity, and light exposure. From an application perspective, this review examines modification approaches such as silver/titanium dioxide composite systems, structurally regulated sustained-release strategies, and anti-adhesion surface designs, while pointing out current limitations in artistic compatibility, long-term durability, and safety assessment. Particularly in scenarios involving food contact and cultural heritage preservation, migration risks from unreacted urushiol monomers and metal nanoparticles, as well as the inherent sensitization potential of urushiol, remain critical challenges for safe application. Accordingly, this paper proposes the establishment of a holistic research framework covering “material design–process control–performance evaluation” and advocates for the development of functional coating systems with low migration, high biocompatibility, and preserved aesthetic value. Such advances are essential to promote the sustainable development and safe application of urushiol-based antibacterial coatings in fields such as cultural heritage conservation, daily-use utensils, and high-end decorative arts. Full article

Chemokines play a central role in orchestrating neutrophil recruitment from the bloodstream and determining their effector functions at sites of infection. Chemokine activity is determined by three key properties: reversible monomer–dimer equilibrium, binding to glycosaminoglycans (GAGs), and signaling through the GPCR class of receptors CXCR1 and CXCR2. In this study, we investigated the structural basis of CXCL8 monomer and dimer binding to GAG chondroitin sulfate (CS) using nuclear magnetic resonance (NMR) spectroscopy, docking, and molecular dynamics (MD) measurements. Our studies reveal that both the monomer and dimer use essentially the same set of basic residues for binding, that the interface is extensive, that the dimer is the high-affinity CS ligand, and that the CS-binding residues form a contiguous surface within a monomer. Several of these residues also participate in receptor interactions, suggesting that CS-bound CXCL8 is likely impaired in its ability to bind receptors. Notably, we observe that the same basic residues are involved in binding CS and heparin/heparan sulfate, even though these GAGs differ in backbone structures and sulfation patterns. We conclude that the strategic distribution and topology of basic residues on the CXCL8 scaffold enable engagement with diverse GAG structures, which likely allows fine-tuning receptor signaling to regulate neutrophil trafficking and effector functions. Full article

Despite the widespread use of photopolymerizable methacrylate resins in additive manufacturing, their potential for creating functional biomedical materials remains untapped. Standard resins, while possessing good technological properties, are typically biologically inert and unable to combat such a critical problem as bacterial colonization. In this work, we propose incorporating selenium nanoparticles (Se NPs) into a photopolymerizable resin based on methacrylate monomers to obtain functional composite materials in the MSLA printing process. Composite material samples made from modified resins showed no structural surface defects and were characterized by a non-uniform distribution of NPs in volume and demonstrated a higher degree of monomer conversion. The materials demonstrated significant antioxidant activity, removing OH-radicals and H₂O₂ and reducing the level of biomarkers of oxidative damage (8-oxoguanine in DNA and long-lived reactive protein species). A dose-dependent bacteriostatic effect was observed in E. coli cell cultures against a background of high cytocompatibility with human cell cultures. The developed photopolymerizable resins modified with Se NPs allow obtaining products that combine the properties of a bacteriostatic agent with antioxidant properties and high biocompatibility, which is of considerable interest in terms of materials for biomedical applications. Full article

This work introduces 2-(azulen-1-yldiazenyl)-5-(thiophen-2-yl)-1,3,4-thiadiazole (L) as a functional monomer capable of forming stable, redox-active films with high affinity for lead in aqueous solutions. L was synthesized and characterized using physical chemical methods and electrochemistry. Polymer films of L were prepared through oxidative electro polymerization on glassy carbon electrodes in L solutions in 0.1 M TBAP in acetonitrile. They were characterized through electrochemistry. The surface of chemically modified electrodes (CMEs) prepared through controlled potential electrolysis (CPE) at variable concentrations, potentials, and electric charges was characterized through scanning electron spectroscopy, atomic force microscopy, and Raman spectroscopy, which confirmed the films’ formation. Electrochemical sensing of the films deposited on these CMEs was tested with respect to heavy metal (HM) ion analysis in aqueous solutions to obtain sensors for HMs. The obtained CMEs presented the best characteristics for the recognition of Pb among the investigated HMs (Cd, Pb, Cu, and Hg). Calibration curves were obtained for the analysis of Pb(II) in aqueous solutions, which allowed for the estimation of a good detection limit of this cation (<10⁻⁸ M) for non-optimized CMEs. The resulting CMEs show promise for deployment in portable environmental monitoring systems, with implications for public health protection and environmental safety. Full article