Search Results (173)

Newly developed hygrosensitive poly(vinyl alcohol) derivatives comprising grafted poly(N,N-dimethylacrylamide) chains of varied length and graft density are presented. The optical, sensing, and hydration properties of these copolymer thin films prepared by spin-coating were systematically studied. Refractive indices (n), absorption coefficients (k), and thicknesses (d) were calculated via curve fitting of the reflection spectra. Reflectance measurements across a relative humidity range of 5% to 95% were used to evaluate the humidity sensing behavior. Coating swelling exceeding 100% was observed. Hydration levels under high humidity conditions were studied using a quartz crystal microbalance method. This revealed approximately 24% water content in the polymer with the higher grafting density and shorter PDMA chains compared to around 31% in the copolymer with longer PDMA brushes that were loosely grafted The potential application of these copolymers as responsive materials for advanced humidity sensing is discussed. A combined optical and gravimetric approach for characterizing the humidity sensing properties of thin nanosized coatings is demonstrated, providing opportunities for advanced characterization of new functional materials, thus broadly contributing to the state of the art of sensor technologies. Full article

Epoxy asphalt is a superior polymer-modified asphalt material; however, significant differences in physicochemical properties, such as solubility parameters and dielectric constants, between epoxy resin and asphalt have led to compatibility issues that hinder its development. This study employed molecular dynamics simulations to investigate the effect of maleic anhydride-grafted styrene-butadiene-styrene (MAH-g-SBS) on the compatibility of epoxy asphalt. By analyzing parameters such as cohesive energy density, solubility parameters, energy distribution, interaction energy, radial distribution function, free volume fraction, and mean square displacement, the molecular mechanism underlying the enhanced compatibility was elucidated. The results indicate that the amphiphilic molecular structure of MAH-g-SBS significantly improves the thermodynamic compatibility between asphalt and epoxy resin, enhances interfacial affinity and stability, reduces the system’s total interaction and nonbonded energies, facilitates the dispersion and permeation of epoxy molecules into asphalt, and increases molecular mobility, thereby comprehensively enhancing the compatibility of the epoxy asphalt blend. Segregation tests and fluorescence microscopy further verified the simulation results, demonstrating that MAH-g-SBS improves the storage stability and phase uniformity of the epoxy asphalt system. Full article

Nanomedicine is rapidly evolving, with tailored nanoparticles enabling precise cellular-level interventions. Despite significant advances, challenges, such as rapid clearance and off-target effects, hinder the clinical translation of many nanosystems. Among the available nanoplatforms, gold nanoparticles (AuNPs) stand out due to their unique surface chemistry, low toxicity, and excellent biocompatibility. In this work, we present a multi-level computational investigation of ultra-small AuNPs coated with non-conventional amphiphilic polymer chains via atomistic and coarse-grained molecular dynamics. Through high-level-resolution atomistic simulations, we investigate how variations in grafting density impact the collective behaviors of these amphiphilic polymer chains within the coating by quantifying relevant conformational, structural, and energetic descriptors, such as the radius of gyration, terminal group presentation, polymer coating thickness, brush height, and solvation energy. Our results reveal a conformational shift of polymer chains from coiled to stretched as grafting density increases, with a direct effect on the polymer conformational regime, terminal group presentation, and coating thickness. In parallel, we further benchmark low-level coarse-grained models using the atomistic data as a reference, demonstrating their ability to correctly reproduce the atomistic trends. This computational investigation reveals how key descriptors vary with grafting density and provides the tools for conducting similar studies on broader time and length scales, thereby advancing the rational design of nanosystems for nanomedicine. Full article

In this study, a flame-retardant wood-polymer composite was produced using huntite-hydromagnesite mineral, recognized for its non- flammability properties. In this context, wood-polymer composites were produced with the co-rotating twin-screw extrusion technique, while polypropylene was applied as the composite matrix, medium density fiberboard waste and inorganic huntite-hydromagnesite mineral were used as the reinforcement material. The proportion of wood powder additives was changed to 10% and 20%, and the huntite and hydromagnesite ratio was changed to 30%, 40%, 50% and 60%. Maleic anhydride grafted polypropylene, i.e., MAPP, was applied as a binder at a rate of 3%. Polypropylene, wood fibers, mineral powders, and MAPP blended in the mixer were processed in the extruder and turned into granules. Structural, morphological, thermal, mechanical, and flame-retardant properties of the composites were analyzed using XRD, SEM, FTIR, TGA, tensile testing, and the UL-94 vertical flammability test. Test samples were prepared to evaluate the physical and mechanical properties with a compression molding machine. It was concluded that the composites gained significant flame retardancy with the addition of huntite hydromagnesite. The potential for using this material in various fields and its compliance with the principles of circular economy and the Sustainable Development Goals (SDG 12) were noted. Full article

Phosphorus contamination in water bodies is a major contributor to eutrophication, leading to algal overgrowth, oxygen depletion, and ecological imbalance. Conventional treatment methods, including chemical precipitation and synthetic adsorbents, are often limited by high operational costs, low biodegradability, and secondary pollutant generation. In this study, a cationic starch was synthesized through free radical graft polymerization of 3-methacrylamoylaminopropyl trimethyl ammonium chloride (MAPTAC) onto corn starch. The modified polymer exhibited a high degree of substitution (DS = 1.24), indicating successful functionalization with quaternary ammonium groups. Theoretical calculations using zDensity Functional Theory (DFT) at the B3LYP/6-311+G(d,p) level revealed a decrease in chemical hardness (from 0.10442 eV to 0.04386 eV) and a lower ionization potential (from 0.24911 eV to 0.15611 eV) in the modified starch, indicating enhanced electronic reactivity. HOMO-LUMO analysis and molecular electrostatic potential (MEP) maps confirmed increased electron-accepting capacity and the formation of new electrophilic sites. Experimentally, the cationic starch showed stable zeta potential values averaging +15.3 mV across pH 5.0–10.0, outperforming aluminum sulfate (Alum), which reversed its charge above pH 7.5. In coagulation-flocculation trials, the modified starch achieved 87% total suspended solids (TSS) removal at a low coagulant-to-biomass ratio of 0.0601 (w/w) using Scenedesmus obliquus, and 78% TSS removal in real wastewater at a 1.5:1 ratio. Additionally, it removed 30% of total phosphorus (TP) under environmentally benign conditions, comparable to Alum but with lower chemical input. The integration of computational and experimental approaches demonstrates that MAPTAC-modified starch is an efficient, eco-friendly, and low-cost alternative for nutrient and solids removal in wastewater treatment. Full article

Ti6Al4V alloy is one of the most widely used orthopedic implants due to its low density, high strength and good biocompatibility, but surface tribology limits its service life and performance. In this paper, a layer of dynamic double-network hydrogel based on a Schiff base bond and a hydrogen bond was grafted on the surface of Ti6Al4V alloy by the mussel chemical self-assembly method. The -NH₂ of acrylamide (AM) and -CHO of vanillin (VA) formed Schiff base bonds to form the first layer of a cross-linked network, a large number of hydrogen bonds were formed between the -OH of vanillin and the -OH of sodium alginate (SA) to provide the second layer of the cross-linked network and the network was properly regulated by introducing core–shell polymer nanoparticles (PDCS). Dynamic self-healing bonds, Schiff base bonds and hydrogen bonds endow qPDCS/SA/VA/AM hydrogels with self-healing ability, and the network structure destroyed under high strain (250%) can be rebuilt under low strain (1%). In the second cycle, G’ and G can recover almost the same value. PDCS/SA/VA/AM hydrogel coating can achieve dynamic repair through reversible Schiff base bond dissociation–recombination during friction, while 1000ppmPDCS/SA/VA/AM hydrogel coating can achieve stable friction reduction and low wear under multiple loads. Under 0.5 N load, the average friction coefficient of 1000ppmPDCS/SA/VA/AM hydrogel coating is as low as 0.157, which is 67.74% lower than the uncoated Ti6Al4V surface under the same load. Under 2 N load, 1000ppmPDCS/SA/VA/AM hydrogel coating remains stable and low-friction, and the average coefficient of friction (ACOF) can reach 0.130, which is 59.27% lower than the uncoated Ti6Al4V surface under the same load. The design idea of the hydrogel network regulated by core–shell polymer nanoparticles (PDCS) to achieve low friction and low wear provides a new strategy for biolubricating materials. Full article

This comprehensive review systematically explores the molecular design and functional applications of nano-smooth hydrophilic ionic polymer surfaces. Beginning with advanced fabrication strategies—including plasma treatment, surface grafting, and layer-by-layer assembly—we critically evaluate their efficacy in eliminating surface irregularities and tailoring wettability. Central to this discussion are the types of ionic groups, molecular configurations, and counterion hydration effects, which collectively govern macroscopic hydrophilicity through electrostatic interactions, hydrogen bonding, and molecular reorganization. By bridging molecular-level insights with application-driven design, we highlight breakthroughs in oil–water separation, anti-fogging, anti-icing, and anti-waxing technologies, where precise control over ionic group density, the hydration layer’s stability, and the degree of perfection enable exceptional performance. Case studies demonstrate how zwitterionic architectures, pH-responsive coatings, and biomimetic interfaces address real-world challenges in industrial and biomedical settings. In conclusion, we synthesize the molecular mechanisms governing hydrophilic ionic surfaces and identify key research directions to address future material challenges. This review bridges critical gaps in the current understanding of molecular-level determinants of wettability while providing actionable design principles for engineered hydrophilic surfaces. Full article

Global challenges in agriculture, in terms of water and nutrient loss control, require new approaches to maintaining or even increasing crop production. Promising materials, such as superabsorbent hydrogels of hybrid types obtained from natural polymers grafted with synthetic polymers, represent a viable solution to solve these problems and maintain a clean environment. In view of this, two types of hydrogels based on sodium alginate, acrylic acid and polyethylene oxide obtained using 5.5 MeV electron-beam irradiation were subjected to degradation through burial in the soil. Swollen hydrogels in two types of water (distilled and tap) and two types of nutrient solutions (synthetic nutrient solution and 100% natural organic nutrient solution), with different pHs of 5.40, 6.05, 7.45 and 7.66, were buried in soil for 30 and 60 days and then extracted and analyzed in terms of their mass loss, swelling behavior and cross-linking structure. The highest mass losses after both 30 and 60 days were recorded for the hydrogels buried in soils whose humidity was maintained by watering them with the basic solutions (tap water and the organic nutrient solution). Structural modifications associated with the degradation process were highlighted by decreases in the cross-link densities and increases in the mesh sizes and swelling. These results were confirmed using FTIR and SEM techniques. Full article

Nanocomposite hydrogels are gaining significant attention for biomedical applications in soft tissue engineering due to the increasing demand for highly flexible and durable soft polymer materials. This research paper focused on investigating and optimizing a procedure for the development of novel nanocomposite hydrogels based on poly(2-hydroxyethyl methacrylate)-co-(2-acrylamido-2-methylpropane sulfonic acid) (HEMA/AMPSA) copolymers. These hydrogels were synthesized through a grafting-through process, where the polymer network was formed using a modified clay crosslinker. The layered double hydroxide (LDH) clay modified with 3-(trimethoxysilyl)propyl methacrylate (ATPM) was synthesized using a novel recipe through a two-step procedure. The nanocomposite hydrogel compositions were optimized to achieve soft hydrogels with high flexibility. The developed materials were analyzed for their mechanical and morphological properties using tensile and compressive tests, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and micro-computed tomography (micro-CT). The swelling behavior, network density, and kinetic diffusion mechanism demonstrated the specific characteristics of the materials. The modified LDH-ATPM was further characterized using Thermogravimetry (TGA), FTIR-ATR and X-ray diffraction (XRD). Biological assessments on human adipose-derived stem cells (hASCs) were essential to evaluate the biocompatibility of the nanocomposite hydrogels and their potential for soft tissue applications. Full article

Langevin Dynamics numerical simulations have been used to compute the force profiles that dipolar polymer brushes exert onto a penetrating colloidal particle. It has been observed that force profiles are strongly influenced by externally applied fields: at large distances from the grafting surface, a force barrier appears, and at shorter distances a region with lower repulsive forces develops. Furthermore, with the right combination of polymer grafting density, polymer chain length and strength of the external field, it is possible to observe in this intermediate region both the existence of net attractive forces onto the penetrating particle and the emergence of a stationary point. The existence of these regions of low repulsive or net attractive forces inside the dipolar brushes, as well as their dependence on the different parameters of the system can be qualitatively reasoned in terms of a competition between steric repulsion forces and Kelvin forces arising from the dipolar mismatch between different regions of the system. The possibility to tune force profile features such as force barriers and stationary points via an external field paves the way for many potential surface–particle-related applications. Full article

Surface modification of various polymer foils was achieved by UV activation and chemical grafting with cysteamine to improve surface properties and antimicrobial efficacy. UVC activation at 254 nm led to changes in surface wettability and charge density, which allowed the introduction of amino and thiol functional groups by cysteamine grafting. X-ray photoelectron spectroscopy (XPS) confirmed increased nitrogen and sulfur content on the modified surfaces. SEM analysis revealed that UV activation and cysteamine grafting resulted in distinct surface roughness and texturing, which are expected to enhance microbial interactions. Antimicrobial tests showed increased resistance to algal growth (inhibition test) and bacterial colonization (drop plate method), with significant improvement observed for polyethylene terephthalate (PET) and polyetheretherketone (PEEK) foils. The important factors influencing the efficacy included UV exposure time and cysteamine concentration, with longer exposure and higher concentrations leading to bacterial reduction of up to 45.7% for Escherichia coli and 55.6% for Staphylococcus epidermidis. These findings highlight the potential of combining UV activation and cysteamine grafting as an effective method for developing polymeric materials with enhanced antimicrobial function, offering applications in industries such as healthcare and packaging. Full article

Using the self-consistent field approach, we studied the salt-controlled vertical segregation of mixed polymer brushes immersed into a selective solvent. We considered brushes containing two types of chains: polyelectrolyte (charged) chains and neutral chains. The hydrophobicity of both types of chains is characterized by the Flory–Huggins parameters ${\chi }_C$ and ${\chi }_N$, respectively. It was assumed that the hydrophobicity is varied only for the polyelectrolyte chains (${\chi }_C$), while other polymer chains in the brush remain hydrophilic (${\chi }_N=0$) and neutral. Thus, in our model, the solvent selectivity ($\chi ={\chi }_C-{\chi }_N$) was varied, which can be controlled in a real experiment, for example, by changing the temperature. At low salt concentrations, the polyelectrolyte chains swell and occupy the surface of the mixed brush. At high salt concentrations, the hydrophobic polyelectrolyte chains collapse and give place to neutral chains on the surface. By changing the selectivity of the solvent and the ionic strength of the solution, the surface properties of such mixed brushes can be controlled. Based on the numerical simulations results, it is shown how the critical selectivity corresponding to the segregation transition in polyelectrolyte/neutral brushes depends on the ionic strength of the solution. It is shown that at the same ionic strength, the critical selectivity increases with an increasing degree of dissociation of charged groups, as well as with an increasing fraction of polyelectrolyte chains in the mixed brush. It has also been shown that at low ionic strengths, the critical selectivity of the solvent decreases with increasing grafting density, while at high ionic strengths, on the contrary, it increases. Within the framework of the mean field theory, a two-parameter model has been constructed that quantitatively describes these dependencies. Full article

As a promising polymer for the production of biomaterials and drug delivery systems, poly(lactic acid) (PLA) is characterized by its relative hydrophobicity, as well as its chemical and biological inertness. Here, we aimed to improve the biological properties of PLA-based materials via the covalent attachment of a hydrophilic biocompatible glycopolymer, namely poly(2-deoxy-N-methacrylamido-D-glucose) (PMAG) on their surface. PMAG is a water-soluble polymer that contains glucose units in its side chains, which are responsible for good biocompatibility and the ability to attach bioactive molecules. In the developed protocol, PMAG was synthesized by controlled radical polymerization in the presence of a reversible addition–fragmentation chain transfer (RAFT) agent, followed by the conversion of glycopolymer terminal dithiobenzoate functionality into a primary amino group (PMAG-NH₂). PLA-based films served as model aliphatic polyester materials for developing the surface biofunctionalization protocol. According to that, PMAG-NH₂ covalent immobilization was carried out after alkali treatment, allowing the generation of the surface-located carboxyl groups and their activation. The developed modification method provided a one-point attachment of hydrophilic PMAG to the hydrophobic PLA surface. PMAG samples, which differed by the degree of polymerization, and the variation of polymer concentration in the reaction medium were applied to investigate the modification efficacy and grafting density. The developed single-point polymer grafting approach provided the efficient functionalization with a grafting density in the range of 5–23 nmol/cm². The neat and modified polymer films were characterized by a number of methods, namely atomic force microscopy, thermogravimetric analysis, ellipsometry, and contact angle measurements. In addition, an ArgGlyAsp-containing peptide (RGD peptide) was conjugated to the PMAG macromolecules grafted on the surface of PLA films. It was shown that both surface modification with PMAG and with PMAG-RGD peptide enhanced the adhesion and growth of mesenchymal stem cells as compared to a neat PLA surface. Full article

With the growing human awareness of trying to reduce the environmental impact in today’s world, the development of new sustainably based materials has been the increasing focus of industry and academia. Biocomposites are environmentally friendly materials produced from raw materials synthesized from renewable sources. In this sense, this work aims to characterize and evaluate the mechanical and thermal performances of biocomposites manufactured from a thermoplastic matrix of high-density bioethylene and obtained from ethanol produced from sugarcane and reinforced with organophilic montmorillonite clay. For this, polyethylene grafted with maleic anhydride (PE-g-MA) was used as a compatibilizer. Dry biocomposites with 1, 3, and 5% organophilic montmorillonite clay, by weight, were subjected to structural (FTIR and DRX), thermal (DSC), thermogravimetric (TG/DTG), thermodynamic–mechanical (DMA), morphological (SEM and MET), and mechanical (tensile, flexural, impact, and shore D hardness tests) characterizations. The DMA experiments were carried out within the viscoelastic region of the polymer. From the obtained results, we notice that, in general, there was an increase in the properties of high-density biopolyethylene (B-HDPE) (without compromising its processability), and therefore, the automotive application of biocomposites compatible with PE-g-MA, containing low levels of organophilic montmorillonite clay, is recommended. Full article

Valorization of potential thermoplastic waste is an effective strategy to address resource scarcity and reduce valuable thermoplastic waste. In this study, new ecofriendly biomass-derived wood polymer composites (WPCs) were produced from three different types of recycled polyethylene (PE) municipal waste, namely linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), or high-density polyethylene (HDPE), and their blend with equal composition (33/33/33 by wt.%). Bamboo particle reinforcement derived from indigenous Ethiopian lowland bamboo (LLB), which had never been utilized before in a WPC formulation, was used as the dispersed phase. Before utilization, recycled LLDPE, MDPE, and HDPE were carefully characterized to determine their chemical compositions, residual metals, polycyclic aromatic hydrocarbons, and thermal properties. Similarly, the fundamental mechanical properties of the WPCs, such as tensile strength, modulus of elasticity, flexural strength, modulus of rupture, and unnotched impact strength, were evaluated. Finally, the thermal stability and interphase coupling efficiency of maleic-anhydride-grafted polypropylene (MAPP) were carefully investigated. WPCs formulated by melt-blending either of the recycled PEs or the blend of recycled PE with bamboo particles showed significant improvement due to MAPP enhancing interfacial adhesion and thermally induced crosslinking, despite inherent immiscibility. These results were confirmed using Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis. The formulated WPCs may promote PE waste cascading valorization, offering sustainable alternatives and maximizing LLB utilization. Furthermore, comparison with well-known standards for polyolefin-based WPCs indicated that the prepared WPCs can be used as alternative sustainable building materials and related applications. Full article