Search Results (5,136)

Jujuboside is an active saponin with anxiolytic and sedative effects, but its oral bioavailability is extremely low. This study prepared an oral film to achieve rapid absorption through the oral mucosa. Using jujuboside as the raw material, the mass ratio of vinyl alcohol polymer to microbial polysaccharide, the ratio of propylene glycol to glycerol and the amount of cellulose ether were selected as influencing factors. On the basis of single-factor experiments, the response surface method was employed to optimize the preparation process of jujuboside oral films, and the effects of these factors on disintegration time and flexibility of the films were investigated. Meanwhile, the content uniformity of jujuboside A and γ-aminobutyric acid in the films was determined by high-performance liquid chromatography. Results showed that the optimized jujuboside oral film had complete molding, a smooth surface, good flexibility, a disintegration time of 25 s in simulated oral environment, and acceptable content uniformity of jujuboside A and γ-aminobutyric acid. The oral film can disintegrate rapidly and release the drug in the oral cavity, and is designed for oromucosal delivery. This oral film is convenient to take, particularly suitable for children, the elderly and patients with dysphagia, providing a new strategy for the clinical application of jujuboside. Full article

The increasing use of bioplastics in packaging applications necessitates rigorous evaluation of their fate in real waste management systems. While bioplastics are often marketed as biodegradable, their actual behavior under mesophilic anaerobic digestion (AD) is frequently insufficiently understood and often overestimated in commercial claims. Polylactic acid (PLA), one of the most widely produced bio-based polymers, has been widely characterized under these conditions, but little is known about the metabolomic changes associated with its biodegradation under mesophilic anaerobic conditions. This study investigates the mesophilic AD (37 °C for more than 3 months) of PLA films (2.5 × 2.5 cm) co-digested with the organic fraction of municipal solid waste (OFMSW). Biogas production and energy yield evaluation were assessed for AD, along with chemical parameters and metabolomic analyses. PLA biodegradation, calculated according to ISO 15985:2014, reached values close to 100% after more than 3 months, highlighting a prolonged lag phase under mesophilic AD conditions. The biogas production yielded about 380 Nm³ per t of volatile solids. Metabolomic profiling during AD revealed that the onset of PLA biodegradation, highlighted also by biogas emission, coincides with the appearance of key metabolites associated with PLA hydrolysis. These findings demonstrate that the mesophilic anaerobic co-digestion of PLA films with OFMSW did not cause any inhibition effect on biogas production. The results demonstrate the feasibility of incorporating PLA into existing organic waste treatment systems, thereby supporting both energy recovery and sustainable waste management. Full article

Polymer-stabilized liquid crystal (PSLC) films are promising for smart window applications because of their transparent-to-scattering switching behavior. However, conventional acrylate-based PSLC films often suffer from poor mechanical robustness and weak interfacial adhesion, limiting their use in flexible devices. Herein, epoxy-based PSLC films have been prepared through radical-promoted cationic photopolymerization using a difunctional epoxy monomer, E6M, and a series of liquid-crystalline monoepoxy monomers, E-nOCB. The effects of alkyl chain parity, chain length, and E6M/E-10OCB ratio on polymer morphology, electro-optical behavior, and peel strength were systematically investigated. Even-numbered E-nOCB monomers favored the formation of regular columnar polymer structures and improved optical contrast, whereas odd-numbered monomers produced more disordered networks with higher peel strength. Among them, the sample prepared with E-10OCB showed a better balance between electro-optical performance and mechanical adhesion. At a fixed total polymer content of 15 wt%, optimizing the E6M/E-10OCB ratio enabled the sample doped with E-10OCB to achieve the highest contrast ratio of 160.91 while increasing the peel strength from 47.28 to 55.69 kPa compared with the sample without E-10nOCB. These results demonstrate that regulating monoepoxy/diepoxy composition and alkyl chain structure is an effective strategy for improving the overall performance of epoxy-based PSLC films for smart windows. Full article

The spreading and film formation of organic polymer solutions on liquid surfaces are key processes in coating, printing, and interfacial processing. However, the mechanisms by which aqueous polymers regulate spreading kinetics and film morphology are not yet fully understood. In this study, the free spreading of Poly(3-hexylthiophene-2,5-diyl) (P3HT)/chlorobenzene solution on poly(vinyl alcohol) (PVA) aqueous surface was employed as a model system to investigate how PVA concentration, molecular weight, degree of hydrolysis, and temperature collectively govern spreading behavior and film formation. Video recording was used to monitor the evolution of the spreading and front-edge morphology, while step-profilometry, UV–visible absorption spectroscopy, and atomic force microscopy were employed to characterize the resulting films in terms of thickness distribution, optical uniformity, and surface roughness. The results reveal that PVA can significantly regulate both the spreading kinetics of P3HT/chlorobenzene droplets and the final film morphology. PVA concentration exhibited a non-monotonic effect on spreading behavior, with intermediate concentrations favoring larger spreading areas and more continuous films. Increasing the PVA molecular weight altered the concentration-dependent spreading window and enhanced asymmetry at the spreading front, whereas reducing the degree of hydrolysis decreased interfacial tension and thereby increased the thermodynamic driving force for spreading, yet the actual spreading rate remained constrained by molecular diffusion, interfacial adsorption, and chain-segment rearrangement. Temperature and a saturated chlorobenzene vapor atmosphere further modulated the interplay among solvent evaporation, interfacial driving force, and viscous dissipation. Under optimized conditions, the resulting P3HT films displayed uniform thickness profiles, consistent optical absorption, and nanoscale surface roughness, and could be repeatedly transferred, assembled into well-defined multilayer structures, and printed onto flexible and curved substrates. These findings demonstrate that PVA aqueous subphase provides a tunable low-shear route for transferable P3HT thin-film fabrication and suggests its potential applicability to other polymer film-forming systems. Full article

Concerns have increased significantly in recent years due to the presence of microplastics in different environmental compartments given that this pollutant can cause adverse effects on the environment and human health. The present review integrates representative studies of Mexican researchers proposing solutions to these concerns, addressing ecological risk and the human food chain, microplastic ingestion by animals, water and sediment pollution, physical/chemical methods for microplastic removal from water, and chemical recycling as a research direction in plastic waste management. Several publications from Mexican institutions are limited to the occurrence and identification of polymers, and a smaller number of documents are focused on solutions to microplastic pollution. Fibers, fragments, spheres, films, and foams have been found in aquatic compartments, sediment, and animals. High ecological risk has been documented in some aquatic compartments. There is a lack of standardized protocols for sampling, extraction, identification, and reporting. Flocculation is a cost-effective approach and may be one of the most promising options for removing microplastics from fresh water. Bioremediation using microorganisms and chemical recycling appear to be the two most widely considered approaches to reverse plastic pollution. National databases, permissible limits, and mandatory monitoring programs should be developed, as these are essential components of an effective regulatory framework. Full article

Polysaccharide-based films are widely studied as topical systems due to their biocompatibility and tunable structural properties. In this study, composite films based on agar–chitosan (A-series) and gellan–chitosan (G-series) were developed with naringin as a bioactive component. The effects of polymer composition and naringin loading on structural organization, swelling behavior, antibacterial activity, and biocompatibility were evaluated. The results show that agar-based systems exhibited significantly higher swelling (~1370%), indicating a more open and highly hydrated structure, whereas gellan-based films formed more compact networks with moderate swelling (~347%). The incorporation of naringin (0.25 g per formulation) led to a pronounced increase in swelling in gellan-based systems (~777%), suggesting reduced network density, while only a slight effect was observed for agar-based films (~1444%). Antimicrobial studies against Staphylococcus aureus confirmed activity in both systems. The gellan-based formulation showed increased antibacterial activity with higher naringin loading (up to 30.0 ± 0.0 mm), whereas agar-based systems demonstrated maximum activity at lower naringin content (27.67 ± 0.58 mm). These findings indicate that antibacterial performance is influenced not only by the amount of bioactive compound but also by matrix structure and release characteristics. In vivo studies of selected A-series samples confirmed good tolerability of the naringin-loaded film (A1N1), with no signs of systemic toxicity or skin irritation, while anti-inflammatory activity under acute conditions was limited. Overall, the developed polysaccharide-based films show potential as topical systems; however, further optimization of polymer composition and formulation parameters is required to achieve a balance between structural stability and biological performance. Full article

Polymer/Silica aerogel (SA) composites improve mechanical properties strategically, but the mixing process disrupts the aerogel’s structure, reducing its efficiency due to polymer chains filling the pores. Pre-vulcanized natural rubber latex (PVNRL) with a higher crosslink density can strain the moving chains, thereby preserving the SA-porous structure in the bulk composite for thermal insulation materials. This study aimed to investigate the effects of PVNRL pre-vulcanization time and SA-immersion time in PVNRL. For PVNRL/SA composite preparation, various PVNRL, from 0 days to 8 days of pre-vulcanization time, were mixed with a fixed SA content of 20 parts per hundred of rubber (phr) using a latex compounding method. Subsequently, the PVNRL/SA slurries were cast on glass plates with 0, 3, and 6 days to obtain the PVNRL/SA composite. Considering the effect of pre-vulcanization time, the crosslink density of the composite increased and revealed a peak at PVNRL/SA with 8-day PVNRL by 7.277 ± 0.881 μmol ${\mathrm{g}}^{-1}$, corresponding to the closest percentage of pore area in the SA’s structure to the pristine SA, and eventually a 42.41% lower thermal conductivity than the PVNRL/SA with 0-day PVNRL exhibited. In addition, the thermal conductivity increased more slowly over immersion time with the presence of 8-day PVNRL. The proposed correlation states that increasing the pre-vulcanization improves the thermal insulation performance of PVNRL/SA composites, emphasizing the reduction of filled SA’s pore with unvulcanized NR chains. Furthermore, the PVNRL/SA composite with 8-day PVNRL maintains thermal stability at 387.3 °C, and can be flexed at room temperature. These fascinating discoveries may be advantageous for further applications related to thin-film and flexible thermal insulation materials. Full article

The present study investigates the presence, sources, and impacts of microplastics (MPs) in different soil types, including agricultural, urban, and forest areas, through a synthesis of results of published scientific papers. MPs originate from a variety of human activities, such as the widespread use of plastic mulch in agriculture and the application of organic fertilizers and treated sewage sludge, as well as from vehicle tire wear, industrial processes, and the gradual degradation of plastic products in the environment. In urban soils, the main sources of MPs are related to road traffic, industrial activity, and landfills, while in forest soils, concentrations are generally lower. However, MPs in forest areas are thought to be carried there by the air, by runoff, or from nearby areas with human activity. Available data show that larger MP particles tend to remain in the surface layers of the soil, while smaller particles can penetrate deeper soil layers, increasing their bioavailability and the likelihood of interaction with microorganisms and plant root systems. In terms of their chemical composition, polyethylene (PE) and polypropylene (PP) polymers dominate in agricultural soils, which is directly linked to agricultural practices, while polystyrene (PS) and polyvinyl chloride (PVC) are more frequently detected in urban soils. The morphological types of MPs include fragments, fibers, and films, while their color characteristics provide clues to possible sources of origin, such as plastic ground covers, tire wear, and packaging materials. Overall, the study’s results underscore the growing environmental significance of MP soil pollution and highlight the need for more effective management and recycling of plastic materials, as well as for further interdisciplinary research aimed at understanding the mechanisms of transport, accumulation, and long-term ecological effects of microplastics in terrestrial ecosystems. Full article

Direct air capture (DAC) requires carbon capture interfaces that operate under highly dilute CO₂ conditions while minimizing thermal and chemical regeneration penalties. Carbonic anhydrase (CA) accelerates the reversible hydration of CO₂ to bicarbonate and is therefore a strong biocatalytic candidate for low-temperature CO₂ capture, but its implementation depends on candidate support materials that combine wet-state accessibility, chemical reactivity, mechanical processability and compatibility with membrane architectures. This study reports the preparation and screening of N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS)-reactive biopolymer composite membranes for future carbonic anhydrase (CA) immobilization. Chitosan particles were precipitated with citrate or tripolyphosphate under high-shear homogenization and compared after lyophilization or convective drying. Chitosan-, shellac-, agarose- and cellulose-acetate-based films plasticized with glycerol and/or polyethylene glycol 400 (PEG-400) were then evaluated by optical microscopy, dry-state penetrometric puncture testing, qualitative EDC/NHS-reactivity mapping and Fourier-transform infrared spectroscopy (FTIR). Freshly precipitated chitosan particles showed dendrite-like high-surface morphologies, while lyophilization preserved porous flocculated aggregates and convective drying produced denser collapsed structures. Neat chitosan showed the highest dry-state puncture force (2.230 ± 0.173 N), whereas chitosan/shellac (0.377 ± 0.044 N) and agarose/chitosan/PEG-400 (0.386 ± 0.038 N) provided the strongest reactive-composite compromise between dry-state puncture resistance and EDC/NHS compatibility. The EDC/NHS reactivity map identified chitosan- and shellac-containing films as the chemically most relevant supports because they provide amine and/or carboxyl functionality, whereas agarose and cellulose acetate alone were not directly suitable for zero-length amidation. FTIR spectra confirmed polymer-specific functional signatures and EDC/NHS-associated changes in carbonyl, amide and C-O/C-O-C regions, especially in shellac- and chitosan-containing composites. The results identify chitosan/shellac as the lead candidate membrane and agarose/chitosan/PEG-400 as a hydration-rich comparator for subsequent carbonic anhydrase immobilization studies. This work should be interpreted as a first-stage materials-screening study of candidate membranes for enzyme immobilization. Full article

Artificial intelligence (AI) and machine learning (ML) algorithms possess the capability to accelerate the design of novel materials; however, their advancement in materials science is severely hindered by a fundamental deficit of experimental data, commonly referred to as data starvation. Unlike solution-based chemistry, where high-throughput (HT) technologies are a well-established standard, the automated synthesis of solid materials—particularly polymers and multicomponent composites—poses an extreme engineering challenge. Furthermore, the traditional, manual research model is inherently flawed by human bias, notably the systematic non-publication of negative results, which deprives AI models of critical boundary information regarding the design space. This paper is the first in a three-part review series defining the architecture of a fully automated, unbiased “data factory” for closed-loop discovery. This section focuses on the physical foundations of the HT workflow: experimental planning, automated synthesis, and material management. Emphasis is placed on the paradigm shift from classical, discrete Design of Experiments (DoE) to the novel concept of Continuous Gradient DoE. It reviews how robotic platforms utilizing precise gravimetric and volumetric feeders, integrated with extruders and in-line capillary rheology, enable the seamless, high-throughput manufacturing of thermoplastics and composites. Moreover, an innovative approach to sample logistics is presented, redefining classical storage patterns through the implementation of Continuous Material Management. This encompasses direct physical tagging (e.g., inkjet marking on continuous filaments or films), spool-based transport systems, and precise, real-time metadata mapping. As demonstrated, the integration of these systems yields an order-of-magnitude increase in productivity (generating tens of thousands of novel material variants annually), a radical reduction in unit costs, and the production of terabytes of standardized, machine-readable data. Establishing this reliable hardware and analytical infrastructure represents the essential first step toward unlocking the full potential of artificial intelligence in advanced materials engineering. Full article

This study evaluates the performance of major types of conventional and bio-based plastic items commonly used in agriculture to provide comprehensive insights into their key structural and functional properties, including the chemical composition of the polymer matrix and additives, mechanical behavior, and thermal and radiometric properties. Twelve agricultural plastic (AP) items were analyzed: covering mulch films, geotextile ground cover, protection fleece and low tunnel fleece cover, fertilizer sack, fly trap, irrigation pipe, tree binding net, guide for tree, silage film and hay bales protection fabric. This selection of APs also encompasses a broad range of basic polymers, including conventional materials (mainly polyethylene and polypropylene) and bio-based formulations (primarily starch- or lignocellulose-containing blends). Mass spectrometry and infrared spectroscopy analyses were performed to assess polymer composition and additives. Mechanical properties were assessed through tensile and puncture tests; in addition, radiometric, thermogravimetric, surface wettability, water absorption and permeability tests were also performed to assess other relevant physical characteristics. The study identified significant differences among bio-based biodegradable APs and compared them with their conventional polyolefin-based counterparts. Material composition and structure were found to critically influence water interactions, shaping the balance between durability, degradation, and crop protection performance. Notably, bio-based mulch films exhibited higher water vapor permeability (0.6–1.1 × 10⁻¹³ g/m Pa s), reduced penetration resistance (12.1 N) and lowered impact and tensile strengths (21.8 MPa). Water interaction tests showed that the starch-based mulch film displayed very high swelling (above 100%), favoring biodegradation, whereas a biodegradable blend based on polyhydroxybutyrate and polybutylene succinate exhibited minimal swelling (<3%). Material composition and morphology were also key determinants of water vapor transport: dense polymer films provided superior moisture barriers (permeability range 0.013–0.04 × 10⁻¹³ g/m Pa s), while fibrous or biodegradable materials allowed enhanced vapor permeability. The results of this study, highlighting functionality, advantages and limitations of biodegradable APs versus conventional APs, are intended to guide future innovation in AP design, ensuring alignment with both the operational demands of modern agriculture and environmental sustainability goals. The data obtained from this study can support scientific advancements and policy recommendations on the use and management of plastics in agriculture. Full article

This paper reports new results on the synthesis and comparative characterization of cellulose nitrates (CNs) derived from Miscanthus × giganteus stems and from commercial microcrystalline cellulose (MCC). Miscanthus CNs synthesized by nitration with mixed sulfuric–nitric acids containing 16–20% water exhibit new functional properties: a high solubility in organic solvents (100% in acetone and 97–99% in alcohol–ether solvent) and a high viscosity (17–51 mPa·s), with a nitrogen content of 10.54–12.08 wt%. CNs from Miscanthus × giganteus are similar in nitrogen content and solubility to those from MCC (11.54% and 99%) but have a significantly greater viscosity (3 mPa·s), which is an undoubted advantage and considerably expands their potential application range. The solubility test of CNs synthesized from both sources demonstrated that Miscanthus CNs have a better film-forming ability. SEM analysis revealed a great difference in fiber length, despite the same cylindrical shape and observed aggregation: 1.0–2.0 mm for CNs from Miscanthus versus 40–60 μm for CNs from MCC. IR spectra of CNs from both sources showed the appearance of five new characteristic frequencies (1632–1633, 1273–1274, 823–826, 748, 677–686 cm^–1 for Miscanthus CNs and 1659, 1277, 832, 747, 691 cm^–1 for CNs from MCC), allowing the obtained compounds to be identified as nitric acid esters of cellulose. According to TGA/DTA analysis, the synthesized polymers have similarly high values of the onset temperature of both intense decomposition (197–198 °C) and narrow exothermic peaks (209–211 °C and 212 °C), respectively, indicating their high thermal stability. The combination of high solubility, viscosity, thermal stability and chemical purity of CNs derived from Miscanthus × giganteus stems suggests that strong thin films can be obtained and recommended for use in the manufacture of nitrocellulose membranes. Full article

Cryogenic environments impose severe thermal and mechanical stresses on polymer components, yet the effects of long-term cryogenic cycling on their subsequent room-temperature performance remain insufficiently understood. This study investigated the influence of cryogenic cyclic aging on the mechanical and tribological behaviour of polyimide (PI)-based materials, including neat PI and composites reinforced with MoS₂, graphite, and/or PTFE. Repeated cryogenic cycling was followed by mechanical characterisation and tribological testing at 25 °C in air and vacuum. This work systematically compares neat and filled PI materials after cryogenic cyclic aging and correlates mechanical changes with transfer-film formation and wear behaviour. Cryogenic cyclic aging had only minor effects on weight and thermal stability but significantly altered the viscoelastic behaviour, increasing creep and residual strain, with variations depending on the polymer structure and filler content. Fracture toughness showed a statistically significant improvement only for PI2 (up to 93%). Changes in PI1, PI3, PI4, and PI5 fell within the experimental scatter and were interpreted as non-significant trends. In air, abrasive wear dominated in unreinforced PI, while graphite/PI composites exhibited adhesive wear and improved transfer film formation, reducing wear rates by up to 26%. In vacuum, the wear rate of aged graphite/PI increased by up to two orders of magnitude. Full article

Tree Bark-Derived bio-based polymers are promising renewable materials for sustainable coatings, surface protection, adhesives, and functional films. This review aims to clarify how harvesting processes affect raw-material quality and coating performance. The materials discussed include Raw Lacquer, pine resin-derived rosin, turpentine, and tree gums. Key harvesting factors, such as incision depth, tapping frequency, collection method, environmental conditions, and tree physiological status, can influence yield stability, impurity content, enzyme activity, viscosity, chemical composition, and batch consistency. These changes further affect film formation, curing behavior, adhesion, barrier properties, corrosion resistance, water sensitivity, and durability. Traditional manual harvesting is flexible but labor-intensive, skill-dependent, and difficult to standardize. Recent precision and intelligent harvesting technologies, including controlled-depth cutting, low-damage incision, multi-sensor perception, adaptive trajectory planning, and closed collection, provide new approaches for improving harvesting efficiency, reducing contamination, protecting tree health, and supplying coating-grade raw materials. This review establishes a framework linking feedstock characteristics, harvesting parameters, raw-material quality, and coating film performance, and outlines future directions for sustainable, automated, and low-damage harvesting to support high-quality bio-based coatings. Full article

The long-term stability of biodegradable polymer coatings deposited by matrix-assisted pulsed laser evaporation (MAPLE) remains insufficiently understood, particularly under ultraviolet irradiation conditions where photochemical effects may accompany material transfer. In this work, thin films of poly(lactide-co-caprolactone)-block-poly(ethyleneglycol)-block-poly(lactide-co-caprolactone), also known as PLCL-PEG-PLCL, are deposited from chloroform solutions by UV-MAPLE using a nanosecond Nd:YAG laser operating at 266 nm over a wide laser fluence range (0.25–0.9 J/cm²). The effect of laser fluence on the morphological, structural, and chemical evolution of the coatings is investigated by atomic force microscopy (AFM), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDS), focused ion beam scanning electron microscopy (FIB-SEM), and X-ray diffraction (XRD). At low laser fluence, relatively homogeneous coatings are obtained while largely preserving the characteristic functional groups of the triblock copolymer. Increasing the laser fluence progressively induces surface restructuring phenomena, including droplets, wrinkles, and the appearance of highly symmetric faceted structures. These entities develop preferentially in samples deposited at elevated fluence and frequently appear only after prolonged aging under ambient conditions, revealing delayed recrystallization behaviour associated with metastable species generated during the deposition process. EDS analyses reveal localized chlorine enrichment within the faceted structures, while FIB-SEM investigations show porous internal morphologies. XRD confirms that the polymer matrix remains predominantly amorphous. The combined observations suggest that UV-MAPLE deposition from chloroform involves not only physical material transfer but also photochemical processes that promote decomposition, recombination, and delayed crystallization phenomena. A phenomenological model describing the successive stages of surface evolution, aging, and recrystallization is proposed. These results provide new insight into the long-term evolution of laser-deposited biodegradable polymer coatings and highlight the importance of solvent selection and processing conditions in determining their stability. Full article