While oxygen-tolerant strategies have been extensively developed for controlled radical polymerizations, the low radical concentrations typically required for high monomer recovery make oxygen-tolerant solution depolymerizations particularly challenging. Here, strategies for open-air depolymerization of atom transfer radical polymerization (ATRP)-synthesized polymers are introduced, achieving high monomer regeneration (>90% depolymerization efficiency). Various approaches for eliminating dissolved oxygen—through the use of a low-boiling point co-solvent or an external radical source—are explored, demonstrating the effectiveness of these methodologies. This work provides a fully oxygen-tolerant, facile, and versatile route for chemically recycling ATRP-synthesized polymers, paving the way for exciting new applications.

Carbon fiber reinforced polymer (CFRPs) are widely used structural materials, thanks to their high strength-to-weight ratio and stiffness. In this field, the use of thermoset polymers (especially epoxy resins cured with amines) as matrix in demanding applications is continuously increasing, leading to a major production of end-of-life (EoL) waste. However, the recycling processes present significant challenges due to the heterogeneity and irreversible three-dimensional cross-linked networks in these materials. Currently, common practices for managing scrap and end-of-life waste include landfilling or incineration, which are clearly inconsistent with the principles of Circular Economy. As a result, there is an urgent need for economically feasible, safe and scalable processes to efficiently recycling these materials, recovering their valuable components.
In the light of the above, this work presents a Lewis-acid catalyzed solvolysis process carried at mild temperatures and atmospheric pressure, applied to three different grades of amine-epoxy thermosets and corresponding CFRPs. At the end of the process, functional oligomeric organic fractions could be recovered, together with integer and clean recycled carbon fibers, which preserve > 95% of their pristine mechanical properties. In this way, a more favorable end-of-life management for amine-cured CFRPs is designed, allowing to beneficial improvement with respect to actual recycling technologies, both from environmental and economical point of views.

Plastic waste recycling remains a critical challenge, with only ~1% of plastic waste undergoing chemical recycling, the rest being burned or landfilled. Polystyrene (PS), a widely produced plastic (~20 million tons annually), is particularly resistant to these processes. Recently, photocatalytic methods have shown potential in transforming PS into valuable chemicals like benzoic acid (BAc).¹ However, efficient C–H bond cleavage remains a major obstacle. This study focuses on the photocatalyst 9-mesityl-10-methylacridinium perchlorate (MA), previously reported by Fukuzumi and coworkers to oxidize p-xylene. While previous reports highlighted its ability to promote PS oxidation to BAc using acid and chloride anions,¹ our findings demonstrate that MA alone can upcycle various grades of PS under visible light (456 nm) or solar radiation, achieving up to 40% yields of benzoic acid (BAc), formic acid (FA), and some acetophenone (ACP).² These results support a mechanism where MA-mediated photo-upcycling of PS to BAc occurs through the abstraction of benzylic H by reactive oxygen species generated from energy or electron transfer from the excited state of MA. The addition of triplet O₂ to these radicals, followed by intra- or intermolecular H atom transfer (HAT), generates C- or O-centered radicals that then undergo β-scission or hydroperoxide fragmentation. Infrared spectroscopy and MALDI-TOF mass spectrometry confirm the formation of intermediate oligomers with terminal carbonyl groups. MA can also convert PS waste, like clear cases and EPS, with conversion efficiency depending on the plastic type. These insights highlight the potential of photocatalysis for PS upcycling, paving the way for efficient plastic recycling.

Polyurethanes are versatile, enabling diverse applications across various fields. However, the single-use materials sector, including most polyurethanes, generates considerable waste, with only 29.7% recycled and 39.5% recovered through energy recovery, not material recycling.[1] This leaves polymer production ultimately dependent on new, often petrochemical-based feedstocks. The eco-design approach involves considering recyclability from the product design phase to meet the challenges of pollution and oil dependence.

While most chemical processes for recycling polyurethanes are hydrolysis and glycolysis, this work aims to degrade them on demand and obtain oligomers that could potentially be re-polymerized. Therefore, photolabile molecules (PLMs) are successfully synthesized and implemented as co-monomers into polyurethanes to degrade them by ultraviolet light irradiation. Studies have proven the efficiency of photodegradation of conventional polymers using PLM.[2], [3], [4]

To produce recyclable and bio-based polyurethanes, the monomers 2,5-Bis(hydroxymethyl)furan (BHMF) and 1,5-Pentane Diisocyanate (PDI) are derivatives of cellulose and L-Lysine Diisocyanate (LDI) comes from protein sources. Polyurethanes are well synthesized, each containing different diisocyanates and PLMs, with molar masses (Mn) up to 83,000g⸱mol-1. Moreover, the type of diisocyanate and the PLM/BHMF ratio influence Mn.

Polyurethane degradation is successfully characterized by nuclear magnetic resonance and size exclusion chromatography. This analysis shows that high Mn before irradiation enables better degradation. The independence of the PLM degradation kinetics from the diisocyanate involved in the polymerization is proven by absorption spectroscopy analysis.

Considering the results obtained, further optimizations will be made to develop on-demand recyclable and bio-based polyurethanes, such as varying the amounts of PLM and integrating aliphatic diols.

In this work, to obtain an electrospun nanofiber with excellent chemical attractiveness and improve mechanical properties, the poly(vinyl alcohol) (PVA) was functionalized through a transesterification reaction using glycidyl methacrylate (GMA) as a modifier in the presence of N, N, N′, N′-tetramethylethylenediamine (TEMED) as a catalyst in DMSO solvent at 60°C for 6 h. Then, pendant methacrylate groups-incorporated polymer (PVA-GMA) was electrospun to obtain nanofibrous web texture. The conditions affecting the homogenous and dense nanofiber deposition onto the Al foil, such as the molar mass of PVA in the synthesis and electrospinning parameters (spinning solvent selection, applied voltage, flow rate, and rotational speed), were investigated in detail to obtain a polymer network with tunable properties. The characteristics of PVA-GMA nanofibers were revealed using different techniques, such as ATR-FTIR, ¹H-NMR, contact-angle-wetting time measurements, and optical microscopy images. The solvent resistance of the nanofibers was assessed by dipping into several solvents, such as water, ethyl alcohol, and acetone. The environmental biodegradability of the nanofibers was followed by burying them in the garden soil for a week. Finally, the chemical attractiveness of the PVA-GMA nanofibers was examined through a thiol-ene click reaction using thiol (-SH) groups containing molecules such as L-cysteine or thioglycolic acid. The results showed that highly chemically active, environmentally biodegradable, and mechanically durable electrospun nanofibrous web texture could be prepared through straightforward chemical modification.

The increasing environmental impact of fossil fuels has accelerated the demand for clean, renewable energy sources. In response, the European Commission has outlined a strategy for transitioning to a decarbonized energy system, with a focus on large-scale hydrogen production and utilization. Electrochemical energy conversion devices, such as polymer electrolyte membrane fuel cells (PEMFCs) powered by green hydrogen, are expected to play a crucial role due to their efficiency and environmental benefits. Nafion has been the standard proton exchange membrane, but the inclusion of fluorine in the European Critical Raw Materials list has prompted the search for fluorine-free, low-cost, and recyclable alternatives.
Sulfonated polyetheretherketone (sPEEK)-based membranes are a promising fluorine-free alternative, offering high proton conductivity, good mechanical properties, and reduced hydrogen crossover. To improve proton transport and mechanical properties, various approaches can be employed. This study explores the incorporation of porphyrins into sPEEK membranes to enhance their performance. Porphyrin loadings ranging from 0.77 to 5 wt% were introduced, and their spectroscopic properties were analyzed using UV-Vis and fluorescence spectroscopy. Several physico-chemical characterizations, including ion exchange capacity, proton conductivity, water uptake, creep, and tensile tests, were conducted to study the interactions between the polymer matrix and the porphyrins. The membrane nanostructure was analyzed using small-angle X-ray scattering (SAXS). Membrane-electrode assemblies (MEAs) were fabricated and tested in PEMFC single cells under various conditions of temperature and humidity. The results indicated a correlation between porphyrin content, porphyrin nature, and fuel cell performance, highlighting the potential of porphyrin-infused sPEEK membranes for advanced PEMFC applications.

Superplasticizers are indispensable for the dispersion enhancement of cementitious particles while reducing water. These additives improve slurry workability and contribute to the production of dense, and high-strength materials. In this study, we highlight the synergistic effect of carboxylate (-COO˗) and sulfonate (-SO3˗) groups through precise microstructure control for high-performance superplasticization in gypsum. Using acrylic acid (AA) and sodium 4-styrenesulfonate (SS) as monomers, we synthesized homopolymers, random copolymers, and block copolymers via RAFT polymerization. The synthesized polymers were evaluated based on adsorption capacity, zeta potential, and adsorption layer thickness. Our results demonstrated that the tailored distribution of -COO˗ and -SO3˗ groups within the block microstructure of polymer significantly enhanced adsorption efficiency, electrostatic interactions, and steric repulsions resulting in superior fluidity in CSH slurry. The block copolymer exhibited an impressive water reduction ratio of 57.7%, outperforming the conventional superplasticizers (15–30%).[1] Additionally, a higher proportion of SS in the block copolymer effectively offset the usual delayed hydration effects of PAA. This work underscores the importance of microstructure optimization in copolymer design for advanced gypsum superplasticizer performance.

Sponges with flame-retardant and superhydrophobic properties offer a dual advantage by enhancing both environmental protection and fire safety. These advanced materials hold significant potential in industrial applications, particularly in oil spill management, marine pollution mitigation, and wastewater treatment, while also ensuring safety in fire-prone environments (1-3). In this study, a novel multifunctional sponge coating with robust superhydrophobicity, superior flame retardancy, and high chemical stability was developed for efficient oil/water separation. The coating material, synthesized using a polymeric resin composed of silica nanoparticles (SiNPs), polydimethylsiloxane (PDMS), and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), was applied to the sponges via dip-coating to enhance their functional properties.
The superhydrophobicity and oil/water separation efficiency of the coated sponges were systematically evaluated through contact angle measurements and oil absorption tests. The highest recorded water contact angle (152°) was achieved with the PDMS/SiNPs/DOPO formulation, confirming the formation of a highly hydrophobic surface. The coated sponges demonstrated an oil/water separation efficiency exceeding 95%, whereas uncoated sponges exhibited significantly lower oil absorption capacity. The flame-retardant performance was assessed through combustion tests. While the uncoated sponge ignited instantaneously, underwent complete combustion, and left no residual structure, the coated sponge exhibited self-extinguishing behavior within 10 seconds and retained its structural integrity post-combustion. SEM analysis of the char layer revealed the formation of a ceramic-like structure, which acted as an effective thermal barrier, significantly enhancing fire resistance. These findings highlight the considerable potential of the developed sponge coatings in enhancing fire safety and environmental protection for industrial applications.

Linear aliphatic polyesters, such as poly-l-lactide (PLLA), have garnered considerable attention as nanocarriers in drug delivery due to their biocompatibility and biodegradability. The main disadvantages of these polymers are the lack of functional groups and high crystallinity degree that may negatively affect drug loading and polymer degradation rate [1].
To overcome these drawbacks, two strategies were investigated, involving the blending of PLLA with polyglycerol adipate (PGA), an amorphous polyester endowed with free OH groups, or the synthesis of branched PLLA (3 or 4 arms) by using polyols, glycerol or diglycerol, as initiators. Usnic acid (UA), a lichen metabolite with well-know antimicrobial and anticancer activity, was investigated for encapsulation as model hydrophobic drug [2].
Blending PLLA-PGA at 50/50 weight ratio allowed us to decrease nanoparticles’ size (from 140 nm of pure PLLA to 110 nm), increase nanoparticle degradation and improve UA loading as well as the ability to decrease UA cytotoxicity towards human hepatocytes (HepG2 cells) [3].
Branche PLLA with molecular weight (MW) ranging from 4100 to 20000 g/mol were obtained by varying L-lactide (L-LA)/OH molar ratios (8, 16 and 24). SAXS evidenced the scattering of a single polymer chain for low molecular weight polymers and the formation of aggregates with planar geometry, possibly vesicles for polymers with 6-12 KDa MW. All branched polymers were amorphous, except for the polymer with the longest branche, and able to self-assemble in water giving 200 nm-in size nanoaggregates. An efficient UA and reduced toxicity were obtained in comparison to linear PLLA.

Carbon fiber (CF) composite materials are widely used in various fields due to the high specific strength, excellent corrosion resistance, low thermal expansion rate, and good workability. In particular, due to the low density and moderate electrical conductivity of CFs, many studies have been conducted on the use of CFs as electromagnetic interference (EMI) shielding materials. However, CF has higher electrical resistance than metal, so thicker layers need to be applied for the same EMI shielding performance. High-performance EMI shielding materials can be produced by improving the electrical conductivity through metal deposition.
In this study, we manufactured materials with improved adhesion between the metal coating layer and the substrate by utilizing edge-selectively oxidized graphene (EOG) and acrylic-based adhesive polymers during the electroless deposition process.
Edge-selectively oxidized graphene was coated on carbon fibers using modified layer-by-layer assembly. The coating layer was formed on the carbon fiber surface through the ion interaction and hydrogen bonding between graphene and polyethyeleneimine. The interfacial shear strength of the specimen coated with graphene once increased by 46.74% .
Acrylic polymers with adhesive properties and the ability to coat through cross-linking were utilized to coat the catalyst for electroless plating. The metal layer coated with adhesive polymers on carbon fibers showed an observed increase of approximately 26% in shear strength.
We improved the interfacial adhesion strength between the electroless plated layer and carbon fibers to overcome the low mechanical strength of carbon fiber-reinforced composite materials with electromagnetic wave shielding effects.

Separator membranes play an essential role in determining lithium-ion battery overall performance. Some of the main detrimental issues of current lithium-ion battery systems are the ones related to battery safety and, in particular, with their thermal regulation.
This manuscript offers a suitable solution by developing separator membranes with thermal regulation through the inclusion of phase change materials (PCM) microspheres.
Composite separator membranes based on PVDF-HFP were prepared with different amounts of PCM microspheres (4 wt.%, 8 wt.% and 16 wt.%). Morphology, degree of porosity, β-phase content was affected by the PCM microspheres content within the membranes. Electrochemical parameters and battery performance depend on PCM content in the membranes, the best cycling behavior being observed for the membrane with 16wt.% of PCM microspheres: 87 mAh.g-1 after 200 cycles and 2C-rate without capacity fade. Therefore, the inclusion of the PCM microspheres in the separator membranes allows to improve thermal regulation of the separator, improving battery safety, and deliver excellent battery performance.

Acknowledgements
Fundação para a Ciência e Tecnologia (FCT): UID/04650, 10.54499/2022.03931.PTDC, 2021.08158.BD (J.P.S.), CEECIND/00833/2017 (DOI: 10.54499/CEECIND/00833/2017/CP1458/CT0017) (RG), 2020.04028.CEECIND (DOI: 10.54499/2020.04028.CEECIND/CP1600/CT0018) (CMC). NGS-New Generation Storage, C644936001-00000045, supported by IAPMEI (Portugal) and European Union NextGenerationEU (PRR).

Understanding the interfacial phenomena involved in the adhesion between elastomer layers on a molecular basis is an important topic from both fundamental and applied aspects [1,2]. This study aims at rationalizing differences in the adhesion behavior of polyurethane (PU) elastomers cured on an EPDM substrate, based on a detailed description of their local network-like topology, determined thanks to ¹H solid-state NMR [3].

The polyurethanes, composed of the same fraction of hydroxy-terminated poly(butadiene) and isophorone diisocyanate, were cured under different reaction conditions – nature and concentration of the catalyst as well as the crosslinking temperature. The rigid domains formed by the hard segments, the proportion of elastically-active chains and the distribution of the topological constraints in the soft domains were investigated by ¹H solid-state NMR. The PU network topology within 20 μm-thick slices collected near the interface with the EPDM layer was systematically compared to the one observed for 60 μm-thick slices, located 500 μm from the interface, corresponding to bulk regions.

Curing at low temperature (30°C) with a low amount of catalyst (0.02 wt %) leads to elastically-active poly(butadiene) chains close to the interface with, on average, higher molecular weights between topological constraints than the ones in the bulk. Such differences between interfacial and bulk regions are not observed any longer as the catalyst concentration is increased to 0.2 wt %. These variations of the local PU network topology, occurring over several tens of micrometers, allow to account for the adhesion testing results.

Textile materials based on cotton fibres are distinguished by their hydrophilicity, which makes them vulnerable and creates good conditions for them to be attacked by various types of microorganisms. These materials can cause various infectious diseases. Modifying cotton fabric with biologically active substances can release and impart microbiological activity to the materials to destroy pathogenic microorganisms or inhibit their growth.
The objective of this study is the modification of cotton fabric with polypropylene imine dendrimer modified with 1,8-naphthalamide. The fabric treatment involves soaking the fabric in a dendrimer solution and drying at 50 °C. The interaction between the fabric and the dendrimer was investigated by fluorescence spectroscopy. The release of the dendrimer from the cotton fabric was studied at three different temperatures in phosphate buffer at pH = 7,4. From the results obtained the cotton used as a matrix for controlled release of biologically active substance exhibited antibacterial activity and can be applied as antibacterial gauzes. The obtained material was tested for singlet oxygen evolution. The sample was tested for Gram-positive and Gram-negative model strains with and without irradiation of the samples. Scanning electron microscope was used to examine the samples with both strains of bacteria under different conditions.

Acknowledgements: The authors gratefully acknowledge the financial support by the European Union-NextGenerationEU, through the National Recovery and Resilience Plan of the Republic of Bulgaria, project № BG-RRP-2.004-0002, „BiOrgaMCT”.