Search Results (220)

Driven by environmental concerns, the packaging industry is shifting toward high-performance and bio-based coating alternatives. In this research, poly(methylmethacrylate) (PMMA) and modified cellulose nanocrystal (m-CNC) were employed as reinforcing agents to develop sustainable poly (lactic acid)-based coatings for packaging applications. Various formulations, influenced by polymer matrix blends and m-CNC loadings (1–5%), were prepared using solvent and applied as protective coating on cardboard paper substrates. The grammage of polymeric coatings (CG) on paper was also investigated using various wet film thicknesses (i.e., 150–250 μm). Accordingly, key parameters including water contact angle, thermal behavior, mechanical performances and barrier properties were systematically evaluated to assess the effectiveness of the developed nanocomposite coatings. As a result, nonylphenol ethoxylate surfactant-modified cellulose nanocrystals exhibited good dispersion and stable suspension in chloroform for one hour, improving compatibility and interaction of polymer–CNC fillers. The water vapor permeability (WVP) of PLA-coated papers was significantly reduced by blending PMMA and increasing the content of m-CNC nanofillers. Furthermore, CNC incorporation enhanced the oil resistance of PLA/PMMA-coated cardboard. Pronounced improvements in barrier properties were observed for paper substrates coated with dry coat weight or CG of ~20 g/m² (corresponding to 250 μm wet film thickness). Coatings based on blended polymer—particularly those reinforced with nanofillers—markedly enhanced the hydrophobicity of the cardboard papers. SEM-microscopy confirmed the structural integrity and morphology of the nanocomposite coatings. Regarding mechanical properties, the upgraded nanocomposite copolymer (PLA-75%/PMMA-25%/m-CNC3%) exhibited the highest bending test and tensile strength, achieved on coated papers and free-standing polymeric films, respectively. Based on DSC analysis, the thermal characteristics of the PLA matrix were influenced to some extent by the presence of PMMA and m-CNC. Overall, PLA/PMMA blends with an optimal amount of CNC nanofillers offer promising sustainable coatings for the packaging applications. Full article

MXenes, a new family of two-dimensional transition-metal carbides and nitrides, have attracted significant interest in biomedicine because of their tunable surface groups and multifunctional properties. Hydrogels, with their three-dimensional polymeric networks rich in water, provide excellent biocompatibility and structural similarity to those of biological tissues. Although synthetic polymer–based MXene hydrogels are well studied, polysaccharide-based systems remain underexplored despite their biodegradability and biomedical relevance. In this work, MXene nanosheets were incorporated into a sodium alginate (ALG)–gellan gum (GG) polymeric blend to develop polysaccharide/MXene hydrogels. Two dehydration approaches, conventional drying and freeze-drying were used to evaluate their influence on the characteristics of the composite, including microstructure, surface roughness, compressive behavior, water states, and thermal stability. Conventionally dried polysaccharide/MXene nanocomposites with 1.0% wt. MXene have reduced the swelling ratio by ~60% and the volume change by 40% compared to polysaccharide blend. Freeze-dried polysaccharide/MXene nanocomposite hydrogels developed a porous, interconnected network, making them promising for applications requiring high surface area, such as adsorption and tissue engineering. In contrast, conventionally dried samples formed compact, smooth structures with improved barrier and mechanical performance. These results demonstrate that the dehydration strategy strongly governs the polymer network architecture, water states, and material functionality, offering pathways to tailor hydrogel modified with MXene for specific biomedical applications. Full article

Sustainable membranes for efficient separation processes are increasingly necessary to counteract the significant environmental and human health impacts of manufacturing conventional membranes, which rely on synthetic polymers, toxic solvents, and harmful additives. A greener approach currently involves the use of bio-based polymers, blending synthetic polymers with biopolymers, utilizing nanocomposites, and greener solvents. Biopolymers are emerging as an environmentally friendly alternative for developing polymeric membranes due to their biological, biodegradable, recyclable, and biocompatible properties. However, the development of sustainable biopolymer-based membranes poses greater challenges to achieving a truly low environmental impact across all aspects of raw material production, manufacturing methods, operational systems, and waste disposal. Another challenge for its market competitiveness is achieving high functional and operational performance, wider applications, low commercial costs, and strong scale-up potential. This critical review assesses the current state of sustainability in membrane manufacturing based on recent literature. It also evaluates the role of biopolymers in sustainable membranes and discusses research opportunities in biopolymer production for membrane manufacturing, highlighting biotechnological tools, the circular economy and waste valorization. Full article

Pineapple waste is an underexplored source for producing nanocomposites, from which nanocellulose, namely cellulose nanocrystals (CNCs) or cellulose nanofibers (CNFs), can be produced. This review summarizes extraction methods from different pineapple residues (leaves, crown leaves, stem, peel, pulp, and pomace), covering top-down processes (hydrolysis, oxidation, carboxymethylation, and mechanical fibrillation) and bottom-up strategies (ionic liquids and deep eutectic solvents). The review examines the influence of the morphology and crystallinity of nanocellulose on the functional performance of the nanocomposites. Strategies for processing pineapple-derived nanocellulose composites are analyzed by technique (solution casting, film stacking, and melt blending/extrusion) and polymer matrices (starch, PVA, chitosan, PLA, PHBV, PBAT, proteins, and polysaccharides), including typical loading levels for most polymer-reinforced systems (0.5–5 wt.%), while higher levels (15–50 wt.%) are used in particular cases such as PVA, CMC, and cellulosic matrices. The impact on mechanical strength, barrier behavior, UV shielding, and optical properties is summarized, along with reports of self-reinforced and hybrid cellulose-derived matrices. A benchmarking section was prepared to show nanocellulose loading ranges, trends in properties, and processing-relevant information categorized by type of matrix. Finally, the review describes the potential roles of pineapple waste within a bioeconomy context and identifies some extraction by-products that could be incorporated into diverse value chains. Full article

Polymer dielectrics offer outstanding advantages for high-power energy storage applications, such as high breakdown strength (E_b) and efficiency (η), while both decrease rapidly at elevated temperature (>150 °C). Although several strategies including nanocomposites and crosslinking have been evaluated to enhance E_b and heat resistance, the discharged energy density (U_d) of polymer dielectrics is still limited by the low dielectric constant (K). Herein, we have implemented a blending strategy by utilizing hydrogen bonding interactions between molecular chains for polyetherimide (PEI) and poly(ester ether urethane) (PEEU). Both the experimental and computational simulation results reveal that the blending can contribute to the increased molecular chain spacing and control the charge transport by destroying the conjugated structure to broaden bandgap and induce deep traps, improving the K and E_b simultaneously. As a result, the blend film achieves an unprecedented U_d of 5.50 with the η above 90% at 200 °C. Furthermore, it exhibits stable performances during ultralong 10⁵ charge–discharge cycles in harsh environments (250 MV/m and 200 °C). This work opens a new avenue to scalable high Ud all-polymer dielectric for high-temperature applications and promotes the understanding of the dielectric behavior of polymer blend films. Full article

The performance of heterogeneous polymer-based materials is largely governed by the efficiency of interfacial adhesion and the strength of interactions between their constituent phases. This work mainly focuses on correlating the properties of dielectrically active interfaces, identified through broadband dielectric spectroscopy (BDS), with the mechanical behavior of heterogeneous polymer-based materials. Blends of polypropylene (PP) and biodegradable poly (butylene succinate) (PBS) were investigated across a wide composition range (100/0, 80/20, 70/30, 50/50, 20/80, and 0/100 PP/PBS). The interface between the immiscible PP and PBS phases induces a Maxwell–Wagner–Sillars (MWS) interfacial polarization in the permittivity spectrum. For the 80PP/20PBS formulation, the high activation energy of this polarization is well correlated with the material’s elevated tensile strength measured under uniaxial tension. A series of nanocomposites based on the 80PP/20PBS blend and reinforced with organically modified montmorillonite (Cloisite 20A) were thoroughly investigated. A strong correlation was established between their mechanical performance and the additional interfacial polarization arising from charge accumulation at the clay–matrix interface. The 80PP*/20PBS–3%C20 nanocomposite demonstrated superior matrix–filler adhesion, reflected by the highest activation energy of interfacial polarization and a marked increase in Young’s modulus (~22%) and zero-shear viscosity η₀ (~44%). Complementary rheological measurements confirmed a substantial increase in viscosity and relaxation time for the 80PP/20PBS–3%C20 nanocomposites, indicating restricted chain mobility and the formation of a percolated network. Morphological analysis by SEM provided insights into the overall microstructure of the polymer blends and nanocomposites. These results demonstrate a direct correlation between interfacial structure, chain dynamics, and macroscopic performance in immiscible polymer blends and nanocomposites. Full article

The growing demand for sustainable materials has intensified research on biodegradable polymers, particularly poly(ε-caprolactone) (PCL), poly(lactic acid) (PLA), and their blends. PLA and PCL offer biocompatibility and biodegradability, making them attractive for biomedical, packaging, and agricultural applications; however, their practical utility remains limited owing to intrinsic drawbacks. PLA has low impact strength and poor thermal resistance, while PCL suffers from low tensile strength and slow degradation kinetics. Blending PLA with PCL can complement their properties, providing a tunable balance of stiffness and flexibility. Further improvements can be achieved through the incorporation of micro- and nanocellulose (NC), which act as reinforcements, nucleating agents, as well as compatibilizers. We critically examine fabrication strategies for NC-reinforced PLA, PCL, and their blends, highlighting NC extraction, surface modification, processing strategies, and dispersion techniques that prevent agglomeration and facilitate uniform distribution. Comparative insights into composite and nanocomposite systems reveal that NC incorporation significantly enhances mechanical properties, thermal resistance, crystallization, and biodegradation kinetics, particularly at low filler loadings, owing to its high surface area, specific strength, and hydrophilicity. The review underscores the potential of PLA/PCL-based nanocomposites as eco-friendly biomaterials with tunable properties tailored for diverse sustainable applications. Full article

The present paper focuses on the effect of carbon nanotubes (CNTs) on the rheological behavior of polyethylene/polypropylene (PE/PP) blends to improve PE/PP mixtures for industrial applications. In our research, 40 wt% HDPE-60 wt% PP blends were produced by extrusion, and 0.59%, 1.18%, and 2.35% multiwalled carbon nanotubes (MWCNTs) were added. Oscillation rheometry was used to study the HDPE-PP-MWCNT nanocomposites and the unfilled polymers at temperatures of 210, 220, 230, 240, and 250 °C in the angular frequency range of 0.05–628.32 rad/s, with 5% deformation. It was demonstrated that in the presence of CNTs, both the complex viscosity and modulus values increase above the percolation threshold. Additionally, it was observed that the crossover modulus (Gx) for all mixtures decreases with increasing temperature. In addition, at 1.18% CNT content, a second crossover appears at all temperatures, and its value increases with temperature. Full article

The production of polymer nanocomposites from supertough blends reinforced with carbon-based nanofillers has garnered attention in recent years due to improvements in their mechanical, thermal, and electrical properties. Currently, the main challenge is to develop materials with balanced performance for diverse industrial demands. In this context, this work aimed to produce nanocomposites of poly(butylene terephthalate) (PBT) and poly(ethylene-octene) grafted with glycidyl methacrylate (POE-g-GMA), reinforced with carbon nanotubes (MWCNTs). The PBT, the PBT/POE-g-GMA blend, and the respective MWCNT nanocomposites were initially premixed in an internal mixer and then processed in a co-rotational twin-screw extruder. After processing, they were injection-molded to obtain tensile, impact, and HDT test specimens. Mechanical (tensile, impact, and Shore D hardness), thermal (differential scanning calorimetry—DSC), thermomechanical (heat deflection temperature—HDT), electrical resistivity/conductivity, morphology, and Fourier transform infrared spectroscopy (FTIR) properties were evaluated. The results demonstrated a good balance among the investigated properties, with improvements in mechanical, thermal, and thermomechanical properties when compared to PBT. The impact strength of the nanocomposites reached 186 J/m, approximately 158% higher than that of neat PBT. The HDT reached approximately 55 °C in the PBT/POE-g-GMA/MWCNT5 nanocomposites, while the crystallization temperature increased by 11 °C, as evidenced by DSC, an aspect of great relevance for industrial applications. Furthermore, the PBT/POE-g-GMA/MWCNT5 nanocomposites exhibited an electrical conductivity of 1.06 × 10⁻⁷ S/cm, indicating potential for electrical applications. Full article

Shape-memory polymers (SMPs) are a unique class of smart materials capable of recovering their original shape upon external stimuli, with thermoresponsive polyurethane (PU) being one of the most widely studied systems. However, the relatively low mechanical strength, thermal stability, and durability of PU limit its broader functional applications. PU/ND composites containing 0.1–0.5 wt.% ND were fabricated via melt blending and injection molding method. The objective was to evaluate the effect of ND reinforcement on the mechanical, scratch, thermal, rheological, and shape-memory properties. Results show that tensile strength increased up to 114% and Young’s modulus by 11% at 0.5 wt.% ND, while elongation at break decreased due to restricted chain mobility. Hardness improved by 21%, and scratch resistance was significantly enhanced, with the coefficient of friction reduced by 56% at low loads. Thermal stability was improved, with the maximum degradation temperature shifting from 350 °C (pure PU) to 362 °C (0.5 wt.% PU/ND) and char yield increasing by 34%. DSC revealed an increase in glass transition temperature from 65 °C to 68.6 °C. Rheological analysis showed an 89% reduction in damping factor (tan δ), indicating enhanced elasticity. Shape-memory tests confirmed notable improvements in both shape fixity and recovery ratios across successive cycles compared to neat PU, with the highest enhancements observed for the 0.5 wt.% PU/ND nanocomposite—showing up to 7.6% higher fixity and 32% higher recovery than pure PU. These results demonstrate that ND reinforcement effectively strengthens PU while preserving and improving its shape-memory behavior, making the composites promising candidates for high-performance smart materials in sensors, actuators, and aerospace applications. Full article

Exhaled breath analysis is emerging as one of the most promising non-invasive strategies for the early detection of life-threatening diseases, especially lung cancer, where rapid and reliable diagnosis remains a major clinical challenge. In this study, we designed and optimized an electronic nose (e-nose) platform composed of quantum resistive vapor sensors (vQRSs) engineered by polymer-carbon nanotube nanocomposites via spray layer-by-layer assembly. Each sensor was tailored through specific polymer functionalization to tune selectivity and enhance sensitivity toward volatile organic compounds (VOCs) of medical relevance. The sensor array, combined with linear discriminant analysis (LDA), demonstrated the ability to accurately discriminate between cancer-related biomarkers in synthetic blends, even when present at trace concentrations within complex volatile backgrounds. Beyond artificial mixtures, the system successfully distinguished real exhaled breath samples collected under challenging conditions, including before and after smoking and alcohol consumption. These results not only validate the robustness and reproducibility of the vQRS-based array but also highlight its potential as a versatile diagnostic tool. Overall, this work underscores the relevance of nanocomposite chemo-resistive arrays for breathomics and paves the way for their integration into future portable e-nose devices dedicated to telemedicine, continuous monitoring, and early-stage disease diagnosis. Full article

The need for new strategies to reduce the susceptibility of polymeric materials to bacterial colonization is growing, especially with the emergence of drug-resistant bacterial strains. Antimicrobial agents used to modify polymers should not only be effective against microorganisms in both planktonic and biofilm states but also be safe and environmentally friendly. Phytochemicals, which are components of essential oils, may be a suitable choice to help combat microbial resistance to antibiotics. Furthermore, they meet the requirements of green chemistry. Essential oils synthesized by plants as secondary metabolites are capable of combating both Gram-positive and Gram-negative bacteria by disrupting lipid bilayers, affecting efflux pumps, compromising the integrity of bacterial cell membranes, and inhibiting the quorum-sensing system. They are also effective as adjuvants in antibiotic therapies. In this review, we outline the mechanism of action of various essential oil components that resulted in enhanced eradication of planktonic bacteria and biofilms. We summarize the use of these antimicrobial agents in macromolecular systems (nanovessels, fibers, nanocomposites, and blends) and provide an overview of the relationship between the chemical structure of phytochemicals and their antimicrobial activity, as well as their influence on the properties of polymeric systems, with a special focus on green active packaging materials. Full article

This present review aims to provide a clear overview of the environmental impact of non-biodegradable materials, and the use of biodegradable materials as their replacements. Non-biodegradable polymers have been used in the past, and now they are considered a threat to the environment. Recently, it has become a necessity to manufacture products with biodegradable polymers to alleviate waste pollution because they can degrade in a short period of time in the environment. Biodegradable polymers can be used in various applications like cosmetics, coatings, wound dressings, gene delivery, and tissue engineering scaffolds. Blending biodegradable polymers could provide an excellent opportunity to produce innovative green biocomposites suitable for any desired applications. This paper reviews all the recent related works on biodegradable PLA and PCL materials and the introduction of fillers for the development of green biocomposites. The properties and characterisation of PLA/PCL blends and PLA-PCL-filler green biocomposites on morphology, thermal, mechanical, thermomechanical, and barrier properties are thoroughly reviewed. The applications, limitations, and future prospects of these green biocomposites is also highlighted. Full article

High permeance combined with high salt/dye separation efficiency is a prerequisite for achieving zero-liquid-discharge treatment of saline textile wastewater by membrane technology. Thin-film nanocomposite (TFN) membranes incorporating porous nanoparticles offer a promising route to overcome the permeability–selectivity trade-off of conventional polymer membranes. In this study, a vacuum-assisted method was used to co-blend ZIF-67 and SiO₂ nanoparticles, while branched polyethyleneimine (PEI) served as a cross-linking bridge, resulting in a high-performance TFN membrane for salt/dye separation. Acting as a molecular connector, PEI coordinated with ZIF-67 through metal–amine complexation and simultaneously formed hydrogen bonds with surface hydroxyl groups on SiO₂, thereby linking ZIF-67 and SiO₂. The resulting membrane exhibited good hydrophilicity and excellent dye separation performance (water flux = 359.8 L m⁻² h⁻¹ bar⁻¹; Congo Red rejection = 99.2%) as well as outstanding selectivity in dye/salt mixtures (Congo Red/MgCl₂ selectivity of 1094). The optimal ZIF@SiO₂-PEI membrane maintained stable dye rejection over a wide range of trans-membrane pressures, initial concentrations, and pH values. These results reveal the huge potential of applying the ZIF@SiO₂-PEI TFN membranes for resource recovery in sustainable textile wastewater systems. Full article

The subject of the conducted study was primarily focused on the development of a new type of polymer blend modified with the use of nanosized fillers. The research concept involved the use of polycarbonate/polyethylene terephthalate glycol (PETG/PC) blends modified with the EBA-GMA impact modifier (ethylene–butylene–acrylonitrile copolymer) and three different types of nanofillers: montmorillonite (MMT), halloysite (HNT), and carbon nanotubes (CNT) of two types. The combination of PC, PETG, and EBA phases was used in order to achieve enhanced mechanical performance and stable processing properties. The results of the conducted study revealed that for the toughened PETG/PC/EBA blends, the impact resistance was strongly improved from the reference by 1.5 kJ/m² to 15 kJ/m². However, the results for the nanocomposites revealed that the MMT and HNT additions were limiting the impact strength. In contrast, the Charpy test results for CNT were again close to 15 kJ/m². The results of the thermal resistance measurements again revealed more favorable properties for CNT-modified PETG/PC/EBA blends. Full article