Abstract: Stimuli-responsive textiles are a rapidly advancing class of functional fiber-based materials able to sense and adapt to environmental triggers. Within these enabling technologies hydrogels and microcapsules are very representative, both of which offer complementary mechanisms for moisture management, controlled release, and adaptive performance. Hydrogels provide soft, water-rich polymer networks with tunable swelling, permeability, and mechanical properties, while microcapsules offer protection and targeted delivery of active agents through engineered shell architectures. When integrated into fibrous networks, these systems can impart dynamic responses moisture, temperature, pH, mechanical stress, light, and chemical or biological agents. This review critically examines progress in the design, synthesis, and textile integration of hydrogel- and microcapsule-based systems, with particular emphasis on materials that exhibit true stimuli-responsive behavior rather than passive or extended-release functionality. Strategies for incorporating bulk hydrogels, micro- and nanogels, and stimuli-responsive microcapsules into fibers, yarns, and fabrics are discussed in addition to key application areas such as smart apparel, medical and hygienic textiles, controlled drug delivery, antimicrobial fabrics, and adaptive filtration media. Current challenges related to durability, washability, response kinetics, scalability, and sustainability are highlighted, while future research directions are proposed to advance the development of robust, intelligent textile systems at the nexus of soft matter science and fiber engineering.

Abstract: The accumulation of polyethylene (PE) waste presents significant environmental and economic challenges, particularly in developing regions where plastic valorisation infrastructure remains limited. In this work, waste polyethylene was upgraded through coordination-catalyzed oxidative functionalization using earth-abundant Schiff base metal complexes of iron, cobalt, manganese, and copper with salen and salophen ligands. The process enables selective incorporation of oxygen-containing functional groups while largely preserving polymer molecular integrity, offering a material-oriented alternative to fuel-focused plastic recycling. Fourier transform infrared spectroscopy confirmed the formation of carbonyl and hydroxyl functionalities, with the carbonyl index (CI) increasing from 0.02 ± 0.01 for untreated polyethylene to 0.48 ± 0.04 and 0.42 ± 0.03 for Fe(salen)Cl and Co(salen) catalysts, respectively, under identical conditions. Salophen-based complexes consistently exhibited slightly higher oxidation efficiencies than their salen analogues. Gel permeation chromatography revealed controlled molecular weight reduction, with number-average molecular weight (Mₙ) decreasing from 62.4 × 10³ g•mol⁻¹ (untreated PE) to 56.8 × 10³ and 54.9 × 10³ g•mol⁻¹ for Fe- and Co-based systems, while dispersity remained within polymer-grade ranges. Differential scanning calorimetry and thermogravimetric analysis showed only minor changes in melting temperature and thermal stability. Surface-sensitive X-ray photoelectron spectroscopy confirmed oxidation localized primarily at the polymer surface, while atomic absorption spectroscopy indicated residual metal contents below 10 ppm. Catalyst reusability studies demonstrated sustained activity over multiple cycles. Overall, this coordination-catalyzed strategy provides a scalable and industrially relevant pathway for upgrading polyethylene waste into value-added functional polymers, with strong potential for integration into emerging circular polymer economies in Nigeria and other African regions.

Abstract: The surface properties and electrical behavior of carbon-based materials can be effectively tailored by energetic ion irradiation. In this study, graphene oxide (GO), cyclic olefin copolymer foils (COC, Topas 112 and 011, respectively) were irradiated with 1 MeV Au ions using a 3 MV Tandetron accelerator at fluences of 1 × 10¹⁴, 1 × 10¹⁵, and 2.5 × 10¹⁵ ions/cm². The irradiation induced systematic modifications in surface chemistry, morphology, wettability, and electrical properties. Compositional changes before and after irradiation were investigated using Rutherford backscattering spectrometry (RBS) and elastic recoil detection analysis (ERDA), while surface morphology and roughness were characterized by atomic force microscopy (AFM), revealing a clear fluence-dependent evolution of nanoscale topography. The vibrational characteristics will be assessed through Raman spectroscopy. Surface wettability was evaluated by static contact angle measurements, and surface free energy was determined using the Owens–Wendt–Rabel–Kaelble (OWRK) method, showing a consistent decrease in water contact angle and an increase in surface free energy with increasing ion fluence in Topas 112/011 but not in GO. Electrical characterization demonstrated a pronounced fluence-dependent decrease in sheet resistivity across all investigated substrates. The results show that 1 MeV Au-ion irradiation enables controlled modification of both surface and electrical properties of carbon-based foils.

Abstract: Owing to their outstanding thermal and mechanical properties, polyimides (PIs), polyamides (PAs), and poly(amide-imides) (PAIs) are essential for developing and manufacturing modern high-tech products, including electroactive ones. Despite their large-scale production for diverse applications, the synthesis of these polymers traditionally relies on highly toxic solvents such as N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidone (NMP), and m-cresol. This work investigates the possibility of replacing these hazardous solvents with a more sustainable and "green" alternative, N-butyl-2-pyrrolidone (NBP). We have thoroughly studied and analyzed the synthesis of various PIs, PAs, and PAIs via one- and two-step polycondensation of tetracarboxylic acid dianhydrides with diamines, low-temperature polycondensation of terephthaloyl chloride with diamines, and low-temperature polycondensation of tetracarboxylic acid dianhydrides and terephthaloyl chloride with diamines, respectively. Our results demonstrate that substituting NBP for NMP presents distinct characteristics and outcomes for each process. By optimizing the reaction conditions, we were able to obtain high-molecular-weight products (Mn=37-346 kDa; Mw=133-537 kDa) for all polymer classes studied. Thus, this work establishes NBP as a suitable and promising solvent for synthesizing PIs, PAs, and PAIs with diverse chemical structures and tunable molecular weight characteristics.

Abstract: The increasing urgency to mitigate plastic pollution has accelerated the shift from linear manufacturing toward circular systems. This review synthesizes current advances in mechanical, chemical, biological, and upcycling pathways, emphasizing how artificial intelligence (AI) is reshaping decision-making, performance prediction, and system-level optimization. Intelligent sensing technologies — such as FTIR, Raman spectroscopy, hyperspectral imaging, and LIBS — combined with machine-learning classifiers have improved material identification, reduced reject rates, and enhanced sorting precision. AI-assisted kinetic modeling, catalyst performance prediction, and enzyme design tools have improved process intensification for pyrolysis, solvolysis, depolymerization, and biocatalysis. Life Cycle Assessment (LCA)–integrated datasets reveal that environmental benefits depend strongly on functional-unit selection, energy decarbonization, and substitution factors rather than mass-based comparisons alone. Case studies across Europe, Latin America, and Asia show that digital traceability, Extended Producer Responsibility (EPR), and full-system costing are pivotal to robust circular outcomes. Upcycling strategies increasingly generate high-value materials and composites, supported by digital twins and surrogate models. Collectively, evidence indicates that AI moves from supportive instrumentation to a structural enabler of transparency, performance assurance, and predictive environmental planning. The convergence of AI-based design, standardized LCA frameworks, and inclusive governance emerges as a necessary foundation for scaling circular plastic systems sustainably.

Abstract: Stimuli-responsive hydrogels are an emerging class of smart materials with immense potential across biomedical engineering, soft robotics, environmental systems, and advanced manufacturing. In this review, we present an in-depth exploration of their material design, classification, fabrication strategies, and real-world applications. We examine how a wide range of external stimuli—such as temperature, pH, moisture, ions, electricity, magnetism, redox conditions, and light—interact with polymer composition and crosslinking chemistry to shape the responsive behavior of hydrogels. Special attention is given to the growing field of 4D printing, where time-dependent shape and property changes enable dynamic, programmable systems. Unlike existing reviews that often treat materials, stimuli, or applications in isolation, this work introduces a multidimensional comparative framework that connects stimulus-response behavior with fabrication techniques and end-use domains. We also highlight key challenges that limit practical deployment—including mechanical fragility, slow actuation, and scale-up difficulties—and outline engineering solutions such as hybrid material design, anisotropic structuring, and multi-stimuli integration. Our aim is to offer a forward-looking perspective that bridges material innovation with functional design, serving as a resource for researchers and engineers working to develop next-generation adaptive systems.

Abstract: The aim of this study is to investigate the impact of layered nano-modifiers with distinct chemical structure and morphology, namely graphene nanoplates (GnP) and sodium montmorillonite (Na-MMT), on thermal degradation of polylactic acid (PLA). The exploration was performed with thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and pyrolytic gas chromatography–mass spectrometry (PyGCMS). The findings revealed a catalytic effect of Na MMT on PLA thermal destabilization, manifested in accelerated degradation and the notable change in the composition of pyrolysis products. In contrast, the incorporation of graphene nanoplates into the PLA matrix induced a “barrier effect”: it imposed diffusion limitations on the emission of volatile degradation products during pyrolysis, which is enhanced the thermal stability of the PLA/GnP composite and led to quantitative alterations in the distribution of major pyrolysis products. To elucidate the underlying degradation pathways, authors proposed a model kinetic analysis of thermal degradation for both PLA/GnP and PLA/Na MMT composites. The analysis clearly distinguished the mechanistic differences between the two systems: while Na MMT promotes catalytic decomposition, GnP primarily acts as the physical barrier retarding mass transport and delaying the thermal degradation development. Good alignment of theoretical model-kinetic predictions with Pyrolysis–GC–MS observations confirms the robustness of suggested kinetic modeling method.

Abstract:

Polyurethane (PU) is widely recognized for its efficient oil sorption properties. However, this capacity is highly dependent on its intrinsic chemical composition and morphological structure which can be altered by mechanical or chemical treatments commonly applied before using as a sorbent. In this study, we present a comprehensive investigation of the oil sorption behavior of both soft and rigid PU foams, and their blade-milled ground (BMG) counterparts obtained by mechanical treatment of several recycled PU-based products, including seats, mattresses, side panel of cars, packaging components, insulating panels of refrigerators and freezers. We found that blade-milling of the soft PU foams leads to a significant reduction in oil sorption capacity, proportional to the extent of grinding. Pristine soft PU foams and the BMG-PUs with intermediate particle size (1 mm –250 μm) exhibited the highest oil uptake (30 -20 g/g), whereas the finest fraction (250 μm – 5 μm) showed lower capacity (3-7 g/g). In contrast, rigid PU foams showed consistently low oil sorption (~5 g/g), with negligible differences between the original and ground materials. At the macroscopic level, optical and morphological analyses revealed the collapse of the 3D porous network and a reduction in surface area. On the microscopic scale, spectroscopic, structural, and thermal analyses confirmed phase separation and rearrangement of hard and soft segmented domains within the polymer matrix, suggesting a different mechanism for oil sorption of BMG-PU. Despite reduced performance compared to pristine foams, BMG-PU powders, especially those with intermediate dimensions and originating from soft PU foams, present a viable, low-cost, and sustainable alternative for oil sorption applications, including oil spill remediation, while offering an effective strategy for effective recycling of PU foam wastes.

Abstract: A co-extrusion system, consisting of two sequential impregnation modules equipped with two heating systems, has been developed aimed at forming carbon yarns impregnated with thermoplastics. It has been shown that to ensure complete impregnation of the formed yarn, it is necessary to maintain the temperature in the extruders at 60-80 °C above the melting temperature of the polymer used. The highest strength achieved in the impregnated yarns was 3.3 GPa, which is 67% of the strength of raw carbon fiber. The degree of strength attained is determined primarily by the viscosity of the polymer melt; the minimum strength of 2.3 GPa and the greatest damage to the carbon fiber during impregnation was observed with the most viscous polymer. For all the studied samples, the elastic modulus is 210-220 GPa, which indicates good orientation and uniform drawing, allowing the rigidity of the raw carbon fiber to be almost completely realized.

Abstract: This study investigated the properties of red algae (RA) biocomposite films reinforced with natural sisal fibers and plasticized with glycerol. The polymer was extracted from locally sourced red seaweed and combined sisal fibers at varying loadings (0–45 wt%) using the doctor blading technique. Composite films were analyzed using a variety of methods to evaluate the chemical composition, thermal behavior and mechanical perfor-mance. Infrared spectroscopy confirmed the presence of kappa-carrageenan as the domi-nant polysaccharide in the RA matrix, whereas elemental analysis verified the dilution of sulfur content and enrichment of carbon with increasing fiber incorporation. Thermal analysis revealed that thermal stability increased with fiber loading, peaking at 30 wt% sisal fiber before decreasing slightly at 45 wt% due to poor fiber dispersion. Mechanical testing demonstrated an optimal balance between strength and flexibility at 30 wt% sisal fiber, where tensile strength and modulus improved increased by more than 40% com-pared to the pure RA film. Overall, the findings demonstrate that sisal fiber reinforcement enhances the structural integrity and stability of RA-based films, supporting their poten-tial as biodegradable alternatives to petroleum-based plastics.

Abstract: The present work explores the viscoelastic properties of a homologous series of orga-nosilicon fluids (polymethylsiloxane fluids) using the acoustic resonant method at a frequency of shear vibrations of approximately 100 kHz. The resonant method is based on investigating the influence of additional binding forces on the resonant characteris-tics of the oscillatory system. The fluid under study was placed between a piezoelectric quartz crystal that performs tangential oscillations and a solid cover-plate. Standing shear waves were established in the fluid. The thickness of the liquid layer was much smaller than the length of the shear wavelength, and low-amplitude deformations al-lowed for the determination of the complex shear modulus G* in the linear region, where the shear modulus has a constant value. The studies demonstrated the presence of a viscoelastic relaxation process at the experimental frequency, which is several or-ders of magnitude lower than the known high-frequency relaxation in liquids. In this work, the relaxation frequency of the viscoelastic process in the studied fluids, the ef-fective viscosity were calculated, the lengths of the shear wave and the attenuation co-efficients were determined.

Abstract: The effect of lignosulfonates (LS) of varying molecular weight compositions (\( \overline{Mw} \) 9–50 kDa) on the behavior and aggregation stability of aqueous dispersions of elemental sulfur (S°) was studied under conditions simulating hydrothermal leaching of sulfide ores. A detailed study was conducted of the physicochemical properties of aqueous LS solutions (CLS 0.02–1.28 g/dm³) obtained from various sources (Krasnokamsk, Solikamsk and Norwegian Pulp and Paper Mills). The composition, molecular weight, and concentration of LS were found to significantly affect their specific electrical conductivity, pH, intrinsic viscosity, and surface activity. It has been shown that the introduction of LS during the formation of sulfur sols promotes their stabilization through electrostatic and steric mechanisms. Optimum dispersion stability (293 K, pH 4.5–5.5) was observed at moderate LS concentrations (0.02–0.32 g/dm³), when a stable adsorption layer forms on the surface of sulfur particles. High-molecular-weight LS samples provideed more effective spatial stabilization of sulfur particles. It has been established that increasing temperature (293–333 K) and changing pH (1–7) significantly affect the aggregative stability of systems, namely: with increasing temperature, sol stability decreases, and, the stabilizing effect of different LS types is reversed with changing pH. The obtained results highlight the potential of using naturally occurring polymeric dispersants to control the aggregation stability of sulfur-containing heterophase systems and can be applied to the design of stable colloidal systems in chemical engineering and hydrometallurgy.

Abstract:

This study investigates the modulation effects of varying infill densities and phase angles on the radiation attenuation properties of three 3D-printed polymers: acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), and thermoplastic polyurethane (TPU). Using the EpiXS software for radiation attenuation simulations, the study assessed the linear attenuation coefficients (LAC) of the materials under different infill densities (30%, 50%, 70%, 90%, and 100%) and phase angles (0°, 30°, 45°, 60°, and 90°) for radiation in the 1-100 keV energy range, which corresponds to the X-ray spectrum. TPU demonstrated the highest attenuation values, with a baseline coefficient of 20.199 cm⁻¹ at 30% infill density, followed by PLA at 18.835 cm⁻¹, and ABS at 13.073 cm⁻¹. Statistical analysis via the Kruskal-Wallis test confirmed that infill density significantly impacts attenuation, while phase angle exhibited no significant effect, with p-values exceeding 0.05 across all materials. TPU showed the highest sensitivity to infill density, with a slope of 1.1194, compared to 0.7257 for ABS and 0.9251 for PLA, making TPU the most suitable candidate for radiation shielding applications, particularly in applications where flexibility and high attenuation are required. The findings support the potential of 3D printing to produce customized, cost-effective radiation protection gear for medical and industrial applications. Future work can further optimize material designs by exploring more complex infill geometries and testing under broader radiation spectra.

Abstract: The sound absorption efficiency of the wood based sandwich panels with reinforced bas-alt fiber reinforced (BFRP), glass fiber reinforced (GFRP), and jute fabric composite materi-als and evaluate their potential as acoustic panels were investigated. Four experimental groups were created. Wood based sandwich panels were reinforced with BFRP (Group A), jute fabric (Group B), GFRP (Group C), and unreinforced (Group D). The sound absorption coefficients of the unreinforced and experimental groups were tested via the impedance tube method, according to ASTM standard E1050 (2006). Attention was paid to the acoustic behavior at low frequencies (200 Hz to 800 Hz), mid frequencies (1000 Hz to 1600 Hz), and high frequencies (1800 Hz to 2400 Hz). The sound absorption coefficient was highest in sapwood at 200 Hz frequency level with 0.67, while the highest in heartwood was 0.05 at 2400 Hz frequency level. It can be suggested that the experimental groups be used as sound absorbing acoustic panels.

Abstract: We present two methods for post-processing thermoplastic fused filament fabrication (FFF) parts in efforts to create suitable low vacuum vessels. We compare ABS-CF, PC, PC+ABS, PAHT-CF, and PPS-CF filaments with and without post-processing. This study finds polycarbonate FFF parts to be suitable for vacuum applications with leak requirements in the 10⁻⁴ − 10⁻⁵ mbar · l · s⁻¹ range after treatment with methylene chloride.

Abstract: In this study, we prepared guar gum (GG) films using a compression molding technique for the first time, incorporating glycerol as a plasticizer and microcrystalline cellulose (MCC) as a reinforcing filler. The chemical structures, thermal properties, crystalline structures, phase morphology, mechanical properties, moisture content, and film opacity of thermo-compressed GG films were investigated. The results show that using glycerol as a plasticizer enhanced the flexibility of the thermo-compressed GG film and promoted its crystallization. The incorporation of glycerol and MCC enhanced the thermal stability of the GG film matrix. The addition of MCC enhanced the tensile strength of the plasticized GG film; however, it resulted in a decrease in elongation at break. The incorporation of MCC in plasticized GG films resulted in enhanced opacity and a decrease in moisture content. Thermo-compressed GG films can be customized to exhibit various properties by adjusting the glycerol and MCC contents, making them suitable for a range of eco-friendly and sustainable packaging applications.

Abstract: Oral drug delivery remains one of the most attractive routes for achieving safe, effective, and controlled therapeutic administration. Hydrogels represent promising systems for this purpose due to their biocompatibility, the versatility of natural and synthetic materials, and their tunable physicochemical properties. Among various candidates, dextrin-based hydrogels are particularly noteworthy, as they can respond to physiological gradients along the gastrointestinal tract, enabling targeted, site-specific, and sustained drug release for both localized and systemic treatments. This study aimed to synthesize and characterize dextrin-based hydrogels formulated from β-cyclodextrin (β-CD), KLEPTOSE® Linecaps (LC), and GluciDex®2 (GLU2) as building units, using citric acid (CA) and pyromellitic dianhydride (PMDA) as cross-linkers, for potential application in oral drug delivery systems. The obtained polymers displayed adjustable particle dimensions, pH-sensitive swelling characteristics, and an optimized cross-linking density, as calculated using the Flory–Rehner theory. Furthermore, rheological evaluations and mucoadhesion assays revealed pronounced viscoelastic behavior and strong adhesion to mucosal surfaces, confirming their suitability for oral drug delivery applications. Overall, these findings underscore the potential of dextrin-based hydrogels as mucoadhesive carriers for oral drug delivery, particularly in the treatment of neurodegenerative disorders, where they may facilitate drug transport across biological barriers and enhance therapeutic concentrations within the brain.

Abstract: Polyethylene terephthalate (PET) is widely used, yet the accumulation of its waste poses serious environmental challenges, making efficient recycling essential. PET glycolysis using EG as solvent has emerged as a green‑recycling strategy. In this study, cyclic alkylamino carbene copper (CAAC‑Cu) complex was prepared as catalyst for PET glycolysis. Under optimized conditions (160 °C, 90 min, catalyst amount 3 wt %, and PET:EG=1:4.), PET conversion reached 98.2 %, the selectivity toward BHET was 88.1 %, and the yield was 86.5 %. Kinetic analysis indicated that the glycolysis follows first‑order kinetics with an activation energy of 98.7 kJ mol⁻¹. In addition, the catalyst can be recovered together with excess EG, and after multiple recycles, PET degradation remained above 95 % and BHET yield stayed above 80 %. A possible mechanism has also been proposed, Cu acts as a Lewis acid coordinating to the carbonyl oxygen of PET, facilitating ester bond activation, while the amino‑carbene forms hydrogen bonds with EG, assisting bond cleavage in a Brønsted‑base manner. This catalytic system provides a novel and efficient approach for the green, high‑performance glycolysis of PET.

Abstract: Polymers are widely used across diverse industries, including medicine, energy storage, construction, aerospace, agriculture, transportation, and electronics. However, the complexity and variability of polymer chemical compositions and structures present significant challenges for their development. The integration of machine learning (ML) algorithms with large datasets has opened new avenues for advancements in polymer science. Polymer informatics focuses on predicting polymer performance and optimizing synthesis conditions using ML models. With the growing availability of comprehensive datasets and ongoing improvements in ML techniques, polymer informatics can now be applied more effectively and systematically. This study provides a concise overview of the application of various ML approaches, including supervised learning, unsupervised learning, and artificial neural networks (ANNs), for predicting and classifying the properties of different polymers.

Abstract: Plastics streams dominated by polyolefins and PVC demand a design framework that links synthesis to end-of-life reactivity. This work integrates polymerization-derived microstructure with depolymerization mechanisms to guide selective valorization. We synthesize mechanistic and kinetic evidence connecting coordination and radical polymerization (linear HDPE, branched LDPE, stereoregular PP; PVC with backbone C–Cl) to degradation pathways, and evaluate catalytic topologies (Brønsted/Lewis acidity, framework Al siting, micro/mesoporosity), initiators, and termination/quench strategies under relevant process variables (temperature, heating rate, vapor residence time, pressure). The analysis shows that microstructure prescribes reaction manifolds and attainable product slates: strong Brønsted acidity and shape-selective micropores favor C₂–C₄ olefins and BTX, whereas weaker acidity and hierarchical porosity preserve chain length to paraffinic oils/waxes; mesopore enrichment shortens contact times and suppresses secondary cracking; initiators lower onset energies and expand operability; diffusion management and surface passivation mitigate deactivation. For PVC, continuous HCl removal and basic/redox co-catalysts or ionic liquids lower dehydrochlorination temperatures and yield cleaner fractions, making staged dechlorination followed by residue cracking essential. Framing process design as “polymerization → structure → depolymerization” enables predictive yield targeting and energy-lean operation across mixed wastes, providing actionable guidance on catalyst selection, severity and residence-time control, regeneration, and integrated halogen management.