This study aims to develop new bio-based materials for food packaging using air spraying as a cost-effective manufacturing method. Materials prepared in the form of films were based on cellulose acetate (CA) modified with chitosan (CS). The morphology, structure and performance in terms of thermal, mechanical, wettability and antibacterial behaviour were studied considering two variables: the solvent used to prepare solutions to be sprayed, acetic acid (HAc) or formic acid (FA) and, the composition of the polymer system, 0%, 2.5%,5% and 7.5% by CS weight. The resulting CA/CS composite films obtained exhibited remarkable flexibility and mechanical strength despite being derived from rigid, high-molecular-weight biopolymers. This flexibility is attributed to the unique droplet-based morphology of the films. Increased chitosan content led to enhanced surface roughness and higher water and oil contact angles, indicating improved hydrophobicity. Notably, films with 7.5% chitosan demonstrated antibacterial activity against E. coli, showing inhibited colony growth compared to pure CA films. Therefore, with this study it has been demonstrated that air spraying enables the fabrication of flexible, mechanically robust, and bioactive CA/CS films without the need for plasticizers. Their unique droplet-based morphology, high water contact angle, and antibacterial activity against E. coli highlight their suitability for sustainable food packaging. The use of biopolymers and an efficient processing method positions this approach as a promising alternative to conventional film-forming techniques.

Conductive hydrogels based on poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) are widely used in bioelectronics because they combine printability with good electrical conductivity. However, their brittle nature restricts their durability, especially in implantable devices that must bend, stretch, and remain reliable over time. A key challenge is therefore to create hydrogels that are both mechanically compliant and electrochemically stable.

In this work, we describe a simple design strategy using Triton X-100, a common surfactant, as a plasticizer for lyophilized PEDOT:PSS hydrogels. Mechanical testing showed that plasticization significantly reduced stiffness and viscosity, while elongation at break more than doubled and fracture strength increased. Together, these improvements converted a fragile material into a tough, flexible, and stretchable conductor. Importantly, the electrical function of the hydrogel was largely preserved.

To evaluate device performance, the plasticized hydrogel was integrated into a polydimethylsiloxane (PDMS) encapsulation mimicking an electrode contact. Cyclic voltammetry remained stable with no significant unwanted redox reactions. Impedance spectroscopy revealed only a small increase at 1 kHz, consistent with fewer electron pathways, but this trade-off was minor compared with the substantial mechanical gains.

Overall, this study shows that simple plasticizer additives can tune the balance between mechanics and conductivity. By achieving softness, toughness, and electrochemical reliability in the same material, this strategy moves PEDOT:PSS hydrogels closer to long-term use in bioelectronic interfaces.

Hydrogels are three-dimensional (3D) polymeric networks capable of absorbing large amounts of water, aqueous solutions, or physiological fluids, while remaining insoluble due to physical and/or chemical interactions [1,2]. Over the last decades, these materials have attracted significant interest due to their ability to respond to external stimuli such as pH, temperature, light, electric fields, or ionic strength. Owing to this stimulus-responsive behavior, so-called smart hydrogels have emerged as versatile platforms for biomedical and materials science applications [2,3]. In this study, semi-interpenetrating polymer network (semi-IPN) hydrogels were synthesized by radical polymerization of poly(N-isopropylacrylamide) (PNIPAAm) in the presence of poly(vinyl alcohol) (PVA), with the aim of evaluating their structural, mechanical, swelling, and bioadhesive properties. PNIPAAm formed a chemically crosslinked thermo-responsive network, while PVA acted as the interpenetrated linear polymer, improving biocompatibility and reinforcing the hydrogel structure. Fourier-Transform Infrared Spectroscopy (FTIR) confirmed the incorporation of PVA into the PNIPAAm matrix, as evidenced by characteristic band modifications. Scanning Electron Microscopy (SEM) revealed the influence of PVA content on the hydrogel morphology. Swelling kinetics demonstrated a temperature-dependent behavior; at 37 °C, a volume contraction was observed due to the phase transition of PNIPAAm. Overall, the results suggest that semi-IPN PNIPAAm/PVA hydrogels are promising materials for biomedical applications requiring tunable mechanical performance, thermo-responsiveness, and enhanced bioadhesion.

Synthetic water-soluble polymers, such as poly(vinyl alcohol) (PVA), are widely used in various applications due to their ability to dissolve in water and their functional properties. However, their environmental impact is a growing concern, as PVA and similar polymers exhibit limited biodegradability under natural conditions, leading to persistence in aquatic environments and potential accumulation in ecosystems. Although certain microorganisms can degrade PVA, this process often requires specialized enzymes, such as pyrroloquinoline quinone (PQQ)-dependent dehydrogenases, which limits the efficiency and scalability of microbial degradation. Enzymatic degradation represents a promising and sustainable alternative for addressing the environmental persistence of aqueous soluble polymers. However, a high efficiency and applicability of such enzymatic processes remains a key challenge. This study explores the use of polyol-based biosolvents to improve the catalytic efficiency of laccase, an oxidoreductase enzyme. Laccase performance was evaluated in biosolvents with varying carbon chain lengths and hydroxyl group contents. Among the tested solvents, widely abundant glycerol notably increased enzyme efficiency. These findings highlight the promising role of biosolvents in optimizing laccase-driven polymer biodegradation, paving the way for more effective and sustainable approaches to polyolefin and plastic waste management. Ongoing research is focusing on refining these enzymatic systems to maximize degradation of PVA under eco-friendly conditions.

This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 (DOI 10.54499/UIDB/50011/2020), UIDP/50011/2020 (DOI 10.54499/UIDP/50011/2020) & LA/P/0006/2020 (DOI 10.54499/LA/P/0006/2020), financed by national funds through the FCT/MCTES (PIDDAC). This work is funded by national funds through FCT – Fundação para a Ciência e a Tecnologia, I.P., under the project GREEN-PATH (Ref. 2023.15169.PEX, DOI 10.54499/2023.15169.PEX). MISA acknowledges FCT for the Ph.D. grant PRT/BD/154714/2023. AMF, APT, and AFS acknowledge FCT for the research contracts CEECIND/00361/2022 (DOI 10.54499/2022.00361.CEECIND/CP1720/CT002), CEECIND/01867/2020, and CEECINSTLA/00002/2022, respectively.

Acrylonitrile-butadiene-styrene (ABS) plastics, commonly found in electronics, automotive parts, and household items, continue to pose a substantial environmental challenge, with the majority still ending up in landfills or incinerators. Dissolution-based recycling methods have emerged as effective alternatives to conventional mechanical recycling, particularly for recovering high-quality fractions. This work explores the use of eutectic solvents (ESs) as renewable, low-impact alternatives for the selective dissolution and recovery of ABS components—specifically, the styrene-acrylonitrile (SAN) copolymer. A computational solvent screening of over 30 000 potential candidates was conducted using the COnductor-like Screening Model for Realistic Solvents (COSMO-RS), followed by experimental validation to assess the solubility of SAN in selected ESs. The solubility of SAN was assessed under mild conditions (60 °C, 1 h), and three ESs systems were found to be effective, with recovery yields up to 70%. The recycled polymer and residues were characterized using Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) analyses. Notably, preliminary results suggest that effective dissolution is possible even at ambient temperature and pressure. These findings highlight the potential of ESs as sustainable and scalable solutions for the recovery of difficult-to-recycle polymeric waste such as ABS.

Acknowledgements:
This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MCTES (PIDDAC). This research is also sponsored by FEDER funds through the program COMPETE—Programa Operacional Factores de Competitividade—and by national funds through the FCT under the project UID/EMS/00285/2020. AMF, FHBS, and AFS acknowledge FCT for the research contracts CEECIND/00361/2022, CEECIND/07209/ 2022, and CEECIND/02322/2020 under the Scientific Stimulus – Individual Call, respectively. VP and LC acknowledge the European Commission for the research grant under Horizon Europe ABSolEU - "Paving the way for an ABS recycling revOLution in the EU" (HORIZON-CL4-2021-RESILIENCE-01-Project: 101058636) HOP ON program.

The increasing demand for functional textile materials has created new challenges for the sector, particularly the need to incorporate advanced manufacturing techniques and innovative finishing processes that can drive the development of next-generation sports textiles. Among the strategies available, the use of microcapsules has emerged as a particularly promising approach, as it enables the controlled incorporation of active agents into fabrics, thereby providing additional and long-lasting functionalities. In this study, an innovative textile finishing treatment was developed through the application of microcapsules containing lemongrass and orange essential oils. The microcapsules were synthesized by in situ polymerization and subsequently applied to polyamide (PA66) fabric using the pad-dry process, ensuring adequate adhesion to the textile substrate. The objective was to combine the intrinsic benefits of aromatherapy with textile performance, ultimately offering potential improvements in both the well-being and physical performance of athletes. The microcapsules obtained exhibited mean diameters of 460.08 nm for lemongrass and 1,121.43 nm for orange, with encapsulation efficiencies of 20.77% and 23.03%, respectively, confirming successful entrapment of the essential oils. Thermogravimetric analysis (TGA) demonstrated the enhanced thermal stability of the encapsulated oils, validating the effectiveness of the polymeric shell. Moreover, scanning electron microscopy (SEM) revealed the heterogeneous morphology of the microcapsules and their deposition on the fabric surface, while Fourier-transform infrared spectroscopy (FTIR) identified functional bands associated with both the oils and the polymeric matrix, evidencing molecular interactions with PA66. Taken together, these results highlight the relevance of microencapsulation as a technological pathway for textile functionalization. Furthermore, the study underscores the potential of this approach to support the development of innovative sports textiles that not only improve consumer comfort but also contribute to health and overall athletic performance.

Introduction. Gas separation membranes enable technologies that use selective permeation to separate gas mixtures of interest, such as biogas or flue gas, thereby reducing greenhouse gas emissions. Adding liquid additives to the polymer matrix creates supported liquid membranes (SLMs), which can improve their CO₂ capture performance. Neoteric additives like deep eutectic solvents (DESs) can be used for SLM production due to their highly adjustable compositions, suitable to tailor task-specific membranes. In this work, This study investigates the impact of different choline chloride (ChCl)-based DES on the stability, physicochemical properties and CO₂/CH₄ separation of DES-based SLMs (DSLMs) using different cellulose-based materials as a polymeric substrate, such as regenerated cellulose (RC), cellulose nitrate (CN) and cellulose acetate (CA).

Methods. DES used in this work were based on ChCl as a hydrogen bond acceptor and different hydrogen bond donors: urea (U), glycerol (Gly) or Malic acid (MalAc) among others. DSLMs were produced by a vacuum assisted method. Structural, morphological and thermal properties of membranes were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy dispersive X-ray (EDX).

Results Single- and mixed-gas tests were conducted and permeability and selectivity of CO₂/CH₄ (αCO₂/CH₄) was calculated. FTIR spectroscopy confirmed the presence of DESs within the polymeric structure. In general, αCO₂/CH₄ of the studied membranes resulted to be competitive with those reported in specialized literature, above 100 in some cases such as ChCl:U SLMs.

Conclusions. DES-based SLMs developed in this work demonstrated strong potential for selective CO₂ separation while also presenting a greener approach within carbon capture technologies, making them promising candidates for carbon capture technologies, including environmental applications such as biogas upgrading.

Coordination polymers containing different metal ions and ligands have been widely studied in materials science and synthetic chemistry. For constructing a coordination polymer, the most useful method is to employ an appropriate bridging ligand. Many multidentate ligands bind to two metal ions in two different directions, which shows bridging capability via simultaneous ligations. In our study, we have selected N'1-((E)-2-hydroxybenzylidene)-N'2-(2-hydroxybenzylidene)oxalohydrazide (L), which is a multidentate ligand that can bind to metal ions from more than one donor’s atom. In the first step, the coordination polymers were prepared by reacting the ligand with vanadium acetylacetonate, which yielded a dioxidovanadium(V) complex. In the second step, dioxidovanadium(V) complex was then reacted with sodium carbonate in ethanol solution, resulting in the formation of the one-dimensional vanadium(V) coordination polymer. A novel one-dimensional metal-based coordination polymer of the composition [VNaO₆C₁₁H₁₄N₃]­_n was characterized by IR and NMR and the structure was established by single-crystal X-ray crystallography. The coordination sphere of the vanadium atom is square pyramidal and chelates to a tridentate (-ONO-) ligand, while the square pyramidal conformation of the sodium atom consists of one bridging oxygen atom link to the vanadium atom and the ligand which coordinates in a bidentate fashion. The coordination polymer showed very selective homogeneous catalytic activity with 80-96% conversion in oxidative bromination of the organic substrate under mild conditions.

The global reliance on plastics has driven significant economic growth, with production surpassing 400 million tons in 2022 [1]. Yet, only around 15% of plastic waste is currently recycled [2] and among polyesters, poly(ethylene terephthalate) (PET) is the most widely recycled. However, the imminent commercialization of poly(ethylene 2,5-furandicarboxylate) (PEF), a bio-based PET alternative, raises concerns about its impact on existing PET recycling streams due to structural similarities and potential co-occurrence.

In this study, we present a greener chemical recycling strategy for PET containing residual amounts of PEF (2%, 5%, and 10%) using a eutectic solvent (ES) system composed of urea and zinc acetate as a catalyst. This work reports, for the first time, the structural and thermal characterization of the resulting copolymers (rPET-co-PEF). The recycled materials exhibited structural and thermal properties comparable to virgin PET, suggesting negligible interference from PEF residues in PET’s recycling.

Additionally, the depolymerization mechanism was investigated through density functional theory (DFT) calculations by using Gaussian software. The results indicate that hydrogen bonding interactions between urea alongside zinc coordination with ester groups, significantly reduce the activation energy of the reaction. These findings confirm the catalytic efficiency of the urea-based ES and support its wider application as a sustainable solution for mixed polyester waste recycling.

REFERENCES

1. Plastics Europe. Plastics - the fast facts. 2023.
2. Timmy Thiounn, Rhett C. Smith, Journal of Polymer Science. 2020, 58, 1347-1364.

The problem of polymer waste (plastic waste) is one of the most acute environmental problems of our time. It is associated with the huge amount of plastic produced and its slow decomposition in the environment.
Long-term studies aimed at the biological decomposition of polyethylene, however, have yielded modest results. In general, the fight against pollution by polymer waste requires a comprehensive approach, including changes in consumer behavior, innovations in materials and technologies, and effective waste management.
In this paper, as a solution to this problem, we propose modifying low-density polyethylene by adding a natural filler - natural rubber.
In this regard, the objects of development and further research were polymer composites based on polyolefins of various classes with the addition of a natural polymer - natural rubber.
Natural rubber (NR) is a biopolymer synthesized by more than 2,000 plant species, most of which belong to Euphorbiaceae or Compositaceae. Natural rubber refers to the coagulated or precipitated product obtained from the milky sap (latex) of the rubber plant (Hevea brasiliensis), which forms unlinked but partially vulcanized polymer chains with a molecular weight of about 106 amu and elastic properties.
The main elements of scientific novelty of the declared work: for the first time a comprehensive study of the properties of mixtures and individual components of polymer compositions based on polyolefins and natural rubber was carried out, physicochemical methods of modification were considered; previously unstudied dependencies of interphase interaction in multicomponent polymer matrix systems were established. Based on the results of the work, the optimal ratio of components in the polymer mixture, the features of the destruction process were determined, and the prospects for further use of the obtained materials were assessed.