Search Results (870)

Background: Microplastics (MPs; <5 mm) are pervasive contaminants that can compromise freshwater wetland integrity and wildlife health, yet field evidence from inland systems and non-invasive biomonitoring remains limited. To address this gap, we provide a non-invasive, feces-based baseline for a key wintering waterbird in an inland soda-lake wetland of Türkiye, supported by polymer confirmation. Methods: We evaluated MP occurrence in fecal deposits of the Greylag Goose (Anser anser), a key wintering waterbird at Lake Erçek (Eastern Anatolia, Türkiye), using non-invasive sampling across five periods (October 2024–February 2025). We collected 400 fecal deposits and pooled them into five time-specific composite samples. Accordingly, temporal comparisons are presented descriptively at the composite (period) level rather than as individual-level statistical inference and quantified suspected MPs by type, shape, size, and color; a representative subset (>300 µm; ~20%) was polymer-confirmed by FT-IR, and particle surfaces were examined by SEM–EDX. Results: In total, 959 suspected MP items were recovered, corresponding to an estimated 1.75–2.85 items per fecal deposit (composite-derived; mean 2.40). MP counts peaked in late autumn–early winter (Time 2–Time 3) and declined toward late winter (Time 5). Fibers predominated (37.22%), followed by fragments (30.55%) and pellets (18.77%); the most frequent size class was 100–300 µm (30.25%), and white/transparent particles were most common (38.52%). FT-IR identified polystyrene, polyethylene, and polyvinyl chloride, while SEM–EDX indicated weathered polymeric surfaces. Conclusions: These findings provide baseline evidence of MP exposure in an inland wetland waterbird and support feces-based monitoring for comparative assessments. Full article

Reversible addition-fragmentation chain transfer mediated polymerization-induced self-assembly (RAFT-PISA) offers an efficient approach for the preparation of polymeric nanomaterials, giving access not only to common structures such as spheres, worm-like micelles and vesicles, but also to much more complex meso-objects. However, when the core forming block polymer possesses a high glass transition temperature (Tg), like poly(methyl methacrylate) or polystyrene (PS), high-order morphologies are particularly difficult to achieve since the glassy core can prevent polymer chain reorganization during PISA. To overcome this issue, we chose to perform visible light-initiated RAFT-PISA of poly(tert-butyl acrylate)-block-polystyrene (PtBA-b-PS) in solvent systems with varying degrees of polarity. More specifically, we prepared different mixtures of diisopropyl ether and ethanol and chose PtBA as macro-CTA due to its broad range of solubility. By varying the ratio between ethanol and diisopropyl ether, we could observe a transition from spherical micelles to vesicles via intermediate structures (e.g., necklace-like micelles, network-like micellar aggregates and wedding rings). This result was particularly remarkable since the experiments were performed near room temperature. We believe that these multiple morphologies were induced by the interactions between the solvent and the corona and the change in swelling of the polystyrene core with styrene monomer that facilitated its rearrangement. We anticipate that this approach could be applied to other polymeric systems with high Tgs. Full article

The coexistence of plastics and metal-based materials in aquatic systems introduces complex interfacial processes that influence pollutant speciation and mobility. This study investigates the role of polystyrene (PS) in promoting UV-induced dissolution of ZnO and Cu₂O in aqueous media, revealing a plastic-mediated pathway for metal ion mobilization. Post-use expanded PS fragments were co-dispersed with the oxides and irradiated at 254 nm for 24 h. Ion concentrations were quantified by ICP-MS, while PS morphology and chemistry were characterized by SEM, EDX, FTIR, Raman, and DSC. The presence of PS markedly enhanced metal release, bringing Zn²⁺ from 29.9 to 50.6 ppm and Cu²⁺ from 1.1 to 26.5 ppm under irradiation, compared to minimal dissolution in the dark. Spectroscopic analyses indicated negligible polymer degradation, suggesting that enhanced dissolution arises from interfacial photooxidation and associated redox/pH microgradients at the polymer–oxide boundary. These findings demonstrate that PS may serve as a catalytic interface that accelerates UV-driven dissolution of otherwise poorly soluble metal oxides. This mechanism expands current understanding of plastic–pollutant interactions and has implications for predicting metal bioavailability and designing strategies to mitigate pollutant release in sunlit marine and coastal environments. Full article

In this paper, a new polymeric membrane including polymers (cellulose acetate, polyethylene glycol 400), copolymer poly(4-vinylpyridine)-block-polystyrene, and TiO₂ nanoparticles were synthesized by the phase inversion method. In order to investigate the presence and the influence of the TiO₂ nanoparticles on the membrane matrix, a polymeric membrane without TiO₂ nanoparticles was prepared by the same preparation method. The structure of the polymeric membranes was characterized by several techniques, such as Fourier transform infrared spectroscopy and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, thermogravimetric analysis, and impedance spectroscopy. Also, the water contact angle, water retention, and porosity were determined. The results showed that the TiO₂ nanoparticles were incorporated into the pores and onto the surface of the polymeric membrane, which resulted in a more uniform structure. In addition, these polymeric membranes were tested for the removal of cadmium ions from synthetic waste-water using a laboratory-scale electrochemical separation system with a custom-built setup. The results showed that the polymeric membrane with TiO₂ nanoparticles showed a high cadmium ions removal rate (95.53%), compared to the polymeric membrane without TiO₂ nanoparticles (85.29%), after a 1.5 h electrochemical separation test. The final results indicated that the polymeric membranes prepared with TiO₂ nanoparticles had excellent thermal stability and exhibited the best ionic conductivity. The electrochemical separation system proved that the obtained polymeric membranes effectively remove cadmium from the synthetic waste-water. Full article

Plastic streams dominated by polyethylene (PE) including PE HD/MD (High Density/Medium Density) and PE LD/LLD (Low Density/Linear Low Density), polypropylene (PP), and polyvinyl chloride (PVC) across Europe demand a design framework that links synthesis with end of life reactivity, supporting circular economic goals and European Union waste management targets. This work integrates polymerization derived chain architecture and depolymerization mechanisms to guide selective valorization of commercial plastic wastes in the European context. Catalytic topologies such as Bronsted or Lewis acidity, framework aluminum siting, micro and mesoporosity, initiators, and strategies for process termination are evaluated under relevant variables including temperature, heating rate, vapor residence time, and pressure as encountered in industrial practice throughout Europe. The analysis demonstrates that polymer chain architecture constrains reaction pathways and attainable product profiles, while additives, catalyst residues, and contaminants in real waste streams can shift radical populations and observed selectivity under otherwise similar operating windows. For example, strong Bronsted acidity and shape selective micropores favor the formation of C₂ to C₄ olefins and Benzene, Toluene, and Xylene (BTX) aromatics, while weaker acidity and hierarchical porosity help preserve chain length, resulting in paraffinic oils and waxes. Increasing mesopore content shortens contact times and limits undesired secondary cracking. The use of suitable initiators lowers the energy threshold and broadens processing options, whereas diffusion management and surface passivation help reduce catalyst deactivation. In the case of PVC, continuous hydrogen chloride removal and the use of basic or redox co catalysts or ionic liquids reduce the dehydrochlorination temperature and improve fraction purity. Staged dechlorination followed by subsequent residue cracking is essential to obtain high quality output and prevent the release of harmful by products within European Union approved processes. Framing process design as a sequence that connects chain architecture, degradation chemistry, and operating windows supports mechanistically informed selection of catalysts, severity, and residence time, while recognizing that reported selectivity varies strongly with reactor configuration and feed heterogeneity and that focused comparative studies are required to validate quantitative structure to selectivity links. In European post consumer sorting chains, PS and PC are frequently handled as separate fractions or appear in residues with distinct processing routes, therefore they are not included in the polymer set analyzed here. Polystyrene and polycarbonate are outside the scope of this review because they are commonly handled as separate fractions and are typically optimized toward different product slates than the gas, oil, and wax focused pathways emphasized here. Full article

Dielectric barrier discharge (DBD) plasma provides a solvent-free and energy-efficient approach for the in situ polymerization of styrene on cotton textiles. Traditional methods for polystyrene (PS) coating often require elevated temperatures, chemical initiators, or organic solvents, conditions that are incompatible with porous, heat-sensitive substrates such as cotton. In this work, we demonstrate that DBD plasma can initiate and sustain styrene polymerization directly on cotton fibers under ambient conditions. FT-IR spectroscopy confirms the consumption of the vinyl C=C bond and the formation of atactic, amorphous polystyrene. Thermogravimetric analysis indicates that the cotton coated with DBD polymerized PS exhibits enhanced thermal stability compared to cotton coated with commercial PS. Additionally, UV aging tests confirm that the plasma-deposited coating maintains its hydrophobicity after exposure to light. Together, these findings highlight DBD plasma as a sustainable and effective approach for producing hydrophobic, thermally robust, and UV-stable textile coatings without the need for solvents, initiators, or harsh processing conditions. Full article

As a sink for microplastics (MPs) in the aquatic environment, sediments have garnered considerable attention. However, the occurrence characteristics of MPs in sediments of different water seasons are not clear, especially for reservoir sediment cores. This study aimed to elucidate the occurrence, spatial and vertical distribution, fragmentation and pollution risk of MPs in the sediment cores of the Xiangxi River, Three Gorges Reservoir (TGR) during different seasons. In sediment cores, the average abundance of MPs was 8.57 × 10³ ± 5.65 × 10³ items/kg DW in the wet season (WS) and 7.98 × 10³ ± 4.00 × 10³ items/kg DW in the dry season (DS), respectively. The abundance of MPs in surface sediments and sediment cores exhibited spatial heterogeneity, reflecting seasonally contrasting hydrodynamic conditions between sites S1 and S3. However, the abundance of MPs in the river estuary was the highest, both in surface sediments and sediment cores. Interestingly, the occurrence characteristics of MPs in surface sediments indicated that in addition to anthropogenic activity, hydrological conditions of the river can also have an impact on the spatial distribution of MP abundance in surface sediments. Polypropylene (PP), polyethylene (PE), polystyrene (PS), and polyethylene-propylene copolymer (EPM) were identified as the dominant polymer types (57–99%), with small-sized microplastics (SMPs, 0–300 μm) being the most prevalent. Water seasons influenced the size distribution of MPs in surface sediments. Using a conditional fragmentation model, MP sources were inferred by comparing fragmentation parameters (λ and α) in sediments with those reported for atmospheric deposition, reservoir water, and water-level fluctuation zone soils. Furthermore, the pollution load index (PLI) exceeded 1, indicating MP accumulation in the sediments. The pollution risk index (PRI) values indicated a considerable (300 < PRI < 1000) pollution risk in two water seasons, primarily due to the presence of polyvinyl chloride (PVC). This study enhances the understanding of MP behavior and associated environmental risks in reservoir sediments, offering valuable insights for future research and pollution mitigation efforts. Full article

Microplastic pollution of ecosystems is considered a modern problem. Freshwater ecosystems, despite the interest shown in their study, remain poorly understood. Lake Baikal (Russia) is one of the least studied freshwater ecosystems in this regard. This large lake is distinguished from others by its high level of biodiversity and clean drinking water. The aim of this study is a multi-matrix investigation of microplastic pollution in one of the lake’s bay. The following matrices are used: surface water, water column, sediment, macrophytes, macroinvertebrates, and fish, as well as ice and snow during the winter. The results show that certain locations exhibit high concentrations of microplastic particles. In some cases, this was due to the properties or characteristics of these locations (littoral zones near the water’s edge, macrophytes with mucus sheaths, ice and snow (potentially, the near-surface water layer after ice melt)), while in others, it was due to localized pollution (pier and ship mooring areas). An analysis of the polymer types of the detected microplastic particles reveals the presence of both common (polypropylene, polyethylene terephthalate, polystyrene, polyethylene, polyvinyl chloride) and rare (polyvinyl alcohol and alkyd resin). Moreover, in some locations, the latter two polymers predominate, a phenomenon rarely observed in other studies. Further research was recommended to focus on the chronic effects of microplastic particles on organisms associated with areas of elevated particle concentrations. Full article

Textile-reinforced concrete (TRC) sandwich panels with lightweight cores are a promising solution for sustainable and slender building envelopes. However, their structural performance depends strongly on the shear connection between the outer shells. This study investigates the flexural behavior of TRC sandwich panels with glass fiber-reinforced polymer (GFRP) rod connectors under four-point bending. Three full-scale specimens were manufactured with high-performance concrete (HPC) face layers, an expanded polystyrene (EPS) core, and 12 mm GFRP rods as shear connectors. The panels were tested up to failure, with measurements of load–deflection behavior, crack development, and interlayer slip. Additionally, a linear-elastic finite element model was developed to complement the experimental campaign, capturing the global stiffness of the system and providing complementary insight into the internal stress distribution. The experimental results revealed stable load-bearing behavior with ductile post-cracking response. A degree of composite interaction of γ = 0.33 was obtained, indicating partially composite action. Slip measurements confirmed effective shear transfer by the GFRP connectors, while no brittle failure or connector rupture was observed. The numerical analysis confirmed the elastic response observed in the tests and highlighted the key role of the GFRP connectors in coupling the TRC shells, extending the interpretation beyond experimental results. Overall, the study demonstrates the potential of TRC sandwich panels with mechanical connectors as a safe and reliable structural solution. Full article

The pervasive presence of nanoplastics (NPs) in the soil environment has been widely documented. However, the mechanisms governing their transport through soil remain poorly understood. This study investigated the migration and vertical distribution of NPs under simulated rainfall, examining the effects of NP properties (concentration, polymer type, aging) and rainfall conditions (duration, pH). The results demonstrated that rainfall facilitated the entry and retention of NPs in soil, with long-term rainfall promoting gradual migration to deeper layers or groundwater. NP mobility was inversely related to their contamination levels. Lower concentrations enhanced downward transport, while higher concentrations led to preferential retention in the topsoil. Due to its hydrophilicity, polyamide (PA) exhibits greater mobility in soil than hydrophobic polystyrene (PS). Both UV aging and acidic rainfall conditions inhibited the migration of NPs, which increased their long-term retention in soil, thereby elevating ecological risk. These results highlight the need for increased attention to the risk of groundwater contamination posed by hydrophilic NPs following long-term rainfall, as well as the threat posed by hydrophobic NPs, particularly after aging and under acidic rainfall conditions, to soil organisms and food safety. Our findings provide critical insights for assessing NP risks in soil environments. Full article

Bangladesh generates approximately 3000 tons of plastic waste daily, and high mismanagement leads to substantial discharge into soils, rivers, and oceans. Limited research exists on plastic pollution along Cox’s Bazar in southeastern Bangladesh, with no studies spanning the entire coast; this study provides the first comprehensive assessment of the full coastline. This study investigates the abundance, types, and distribution of macro-, meso-, and microplastics in sediments from 23 stations covering Tourism, Active, and Less Active areas. Plastics were classified by size, shape, color, and polymer composition using stereomicroscopy and Fourier Transform Infrared Spectroscopy (FTIR), while spatial patterns of microplastic polymers were analyzed using Inverse Distance Weighted (IDW) interpolation. A total of 11,558 plastic particles were identified, with microplastics dominating (409.04 particles/m²), followed by mesoplastics (60.7 particles/m²) and macroplastics (32.8 particles/m²). Expanded polystyrene (EPS) and fragments were the most prevalent shapes, while transparent-white particles dominated in color. Polystyrene (PS), polypropylene (PP), and polyethylene (PE) comprised over 95% of polymers. IDW mapping highlighted Tourism, urban, and industrial zones as microplastic hotspots, with higher abundances in tourism areas. These findings provide a baseline for monitoring coastal plastic pollution and emphasize improved plastic management and recycling, contributing globally to understanding contamination in rapidly urbanizing, tourism-driven developing regions. Full article

The increasing use of biodegradable plastics derived from renewable sources (PLA, PHB, PBAT, and others) in the packaging industry raises controversies and risks related to potentially integrating these plastics into municipal waste streams, which may significantly hinder future recycling efforts. This publication addresses this issue by investigating a selected bio-based and biodegradable commercial mixture of poly(lactic acid) and poly(butylene adipate terephthalate) (PLA/PBAT), referred to as (BIO), in blends with polypropylene (PP) and polystyrene (PS). The blends were prepared with three different mass contents of 1, 5, and 10 wt.% using (PP) and (PS) as base materials. The effects of introducing biodegradable and bio-based plastics into municipal waste streams (PCR—Post-Consumer Recycling), which typically contain polypropylene, various grades of polyethylene, and polystyrene, remain unknown. The purpose of the study was to assess the consequences of contaminating municipal waste destined for recycling (using PP and PS as examples) with small amounts (between 1 and 10%) of BIO plastics. The designed experiment and the obtained results simulate the expected presence of BIO contamination in future PP and PS recyclates. The prepared mixtures were subjected to injection molding to produce test specimens, which were then analyzed for changes in their physical properties such as tensile strength, impact strength and hardness. Thermal properties were assessed using Differential Scanning Calorimetry (DSC), while dynamic properties were analyzed at variable temperatures using Dynamic Mechanical Thermal Analysis (DMTA). The tests provided insights into how the addition of selected, but insignificant ratios (of 1 to 10%) of biopolymers affects the properties of (PP) and (PS) compared to materials without content of biopolymers. The conducted tests of mechanical properties (static and dynamic) and thermomechanical properties have shown that the change in the properties of the mixture depends not only on the amount of biodegradable polymer but also on the nature of the load. It would be advisable to analyze mechanical properties in relation to the duration of the load; therefore, a long-term load analysis is necessary. For dynamic tests, a decrease in impact strength was demonstrated with increasing biodegradable polymer content in the produced mixtures. Similar behavior was recorded for hardness measurements. The results underscore the need for continued research, given the valuable findings for processors and the advancement of mechanical recycling technologies. Full article

Tailoring the spin crossover (SCO) effect in molecular materials remains a fundamental challenge, driven by the need to control critical parameters, such as the spin transition temperature (T₁/₂), hysteresis width, cooperativity, and switching kinetics for applications in sensing, memory, and actuation devices. SCO behavior is highly sensitive to small changes in the structure or crystal structure of the surrounding environment. In this context, achieving predictable and reproducible control remains elusive. Embedding SCO complexes into polymer matrices offers a more versatile and processable approach, but understanding how matrix–guest interactions affect spin-state behavior is still limited. In this study, we investigate a polymer-mediated strategy to tune SCO properties by incorporating the well-characterized Fe(II) complex [Fe(1,10-phenanthroline)₂(NCS)₂] into three polymers with distinct structural features: polylactic acid (PLA), polystyrene (PS), and polysulfone (PSF). In terms of potential electrostatic interaction between the complex and the polymeric matrixes, the polymers offer distinct features. Either there does not seem to be any specific interaction (PLA case) or, rather, there is π-π stacking between the aromatic rings of the SCO complex, and the corresponding ones present either in the backbone or in the side chain of the polymer (PSF and PS, respectively). The latter can potentially influence spin-state energetics and dynamics. Importantly, we also reveal and quantify the migration behavior of SCO particles within different polymer matrices, an aspect that has not been previously examined in SCO–polymer systems. Using magnetic susceptibility, spectroscopic, diffraction, and migration studies, we show that the polymer environment, PLA as well, actively modulates the SCO response. PSF yields lower T₁/₂, slower switching kinetics, and enhanced retention of the complex, indicative of strong matrix confinement and interaction. In contrast, PLA and PS composites exhibit sharper transitions and higher migration, suggesting weaker interactions and greater mobility. In addition, the semi-crystalline nature of PLA seems to induce the extension of the hysteresis width. These results highlight both the challenge and the opportunity in SCO polymer composites to tune SCO behavior, offering a scalable route toward functional hybrid materials for thermal sensing and responsive devices. Full article

Microplastics (MPs) and nanoplastics (NPs) are emerging aquatic contaminants that pose environmental and public health risks due to their persistence, ubiquity, and ability to adsorb co-contaminants. This scoping review synthesises findings from 57 experimental studies and five review studies published between 2019 and 2025 on the use of biochar-based materials for the removal of microplastics from water and wastewater. Guided by the hypothesis that surface-modified biochars, such as magnetised, surfactant-coated, or chemically activated forms, achieve high removal efficiencies through multimodal mechanisms (e.g., electrostatic attraction, hydrophobic interactions, π–π stacking, and physical entrapment), this review applies PRISMA-based protocols to systematically evaluate biochar feedstocks, pyrolysis conditions, surface modifications, polymer types, removal mechanisms, and regeneration approaches. Scopus, Web of Science, and PubMed were searched until 30 May 2025 (English-only), and 62 studies were included. The review was not registered, and no protocol was prepared. The results confirm a high removal efficiency (>90%) in most experimental studies, particularly under controlled laboratory conditions and using pristine polystyrene. However, the performance declines significantly in complex matrices (e.g., wastewater and surface water) owing to dissolved organic matter, ionic competition, and particle heterogeneity, thus supporting the guiding hypothesis. This review also identifies critical methodological gaps, including narrow plastic typologies, a lack of standardised testing protocols, and limited field-scale validation. Addressing these gaps through environmentally realistic testing, regeneration optimisation, and harmonised methods is essential for transitioning biochar from a promising sorbent to a practical water treatment solution. Full article

We report measurements of ultrafast photoinduced charge separation and recombination processes in the conjugated donor–acceptor (D-A) polymer PSBTBT, both as pure film and blended in various polymer matrices. Using time-resolved terahertz spectroscopy (TRTS), time-dependent photoconductivity is measured for samples with PSBTBT weight fractions (W_PSBTBT:W_PE/PEG/PS) of 2.0% dispersed in high-density polyethylene (HDPE), polyethylene glycol (PEG), and polystyrene (PS). Charge carrier generation is an intrinsic feature of conductive polymers that occurs on sub-picosecond and longer timescales and is attributed to initially generated dissociation of bound polaron pairs into free carriers that reside on polymer chains, or to adjacent interchain charge transfer and migration. Both interchain and interfacial charge transfer contribute to the measured photoconductivity of the samples, which is found to increase as a function of increasing local polarity and an increasingly hydrogen-bonded environment. Pure-PSBTBT polymer film, PSBTBT dispersed in PS, and PSBTST dispersed in HDPE were all found to exhibit shorter photoconductive free-carrier long-time signal decay than PSBTBT in a hydrogen-bonded, semi-crystalline PEG environment. Full article