Polymat

ABSTRACT Polylactide (PLA) and polycaprolactone (PCL) biocomposites were prepared with modified rice husk (RH). In this context, RH was treated with maleic anhydride (MA) and maleated PLA (i.e., coupling agent [CA]) forming modified RH (i.e., RH‐MA and RH‐CA, respectively). Several formulations were tested from biocomposites of PLA and PCL with different percentages of modified RH where the best results were obtained when using 5% with respect to the used mixing method. Pure PLA and PCL‐ modified RH biocomposites were first obtained, then each of them was further involved in cross blends' formation with each other. Different characteristics were studied for the prepared modified RH polymeric biocomposites for future expected applications in biomedical fields and packaging. Accordingly, several PLA and PCL‐ modified RH biocomposites were toxic on proliferation of cancer cells with inhibitory effect against biofilm formation of bacterial cells in case of MSSA or Pseudomonas aeruginosa . Also, the prepared biocomposites recorded low water vapor and oxygen transmission rates (WVTR, OTR) which indicated their possible application as packaging materials for food at low moisture level or for dry food.

Water purification and treatment methods are becoming increasingly complex due to the use of new additives, solvents, pesticides, dyes, and other emerging pollutants in industry, agriculture, and households. Consequently, the search for new water treatment techniques and materials that can help reduce this environmental impact has become a major focus in the field of green chemistry. In this work, the photocatalytic degradation capacity of composites containing TiO2 nanoparticles (TNPs) for the removal of organic pollutants in water was studied. The TNPs were immobilized in bio-based hydrogel microparticles, which were prepared using microfluidic techniques. The composition of the dispersed phase was optimized with a lab-on-a-chip device, resulting in composite microparticles with a narrow size distribution. UV–visible spectroscopy results indicated that increasing the concentration of TNPs in the hydrogel microparticles enhanced the photodegradation performance of the new composite. Remarkably, it was able to efficiently degrade nearly 90% of reference dyes after four adsorption–desorption cycles.

Bioresorbable nanopatterned scaffolds functionalized with polydopamine (PDA) and graphene oxide (GO) have been shown to promote the differentiation of murine neural stem cells (mNSCs) toward neural and glial lineages. Herein, we aim to evaluate the compatibility of these scaffolds for the culture and differentiation of both human embryonic (hESCs) and induced pluripotent (hiPSCs) stem cells. Our results indicate that PDA and GO scaffolds support the topographic alignment of hESCs and hiPSCs cultures, while preserving their pluripotency characteristics. Upon differentiation, PDA and GO scaffolds guide cell specification toward the neuroectoderm germ layer and the neural crest. This promotes enhanced differentiation into both neural and supportive glial cells of the central nervous system (CNS), as well as Schwann cells of the peripheral nervous system (PNS). Moreover, nanopatterned scaffolds also support the differentiation of hESCs and hiPSCs toward endothelial precursors. These findings establish a novel culture platform that enables combined differentiation pathways, potentially relevant for applications in personalized medicine and regenerative cell therapy.

ABSTRACT External catalysts were used to promote dynamic exchange reactions within polyhydroxyurethanes (PHUs) derived from 6‐membered cyclic carbonates (6CCs). Owing to the presence of both carbamate and ester linkages in the network, two types of covalent exchange reactions; transcarbamoylation and transesterification can occur. A wide variety of catalysts were evaluated for their ability to promote exchange reactions, including dibutyltin dilaurate (DBTDL), potassium methoxide (MeOK), iron(III) acetylacetonate (Fe(acac) 3 ), 1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene (TBD), 4‐dimethylaminopyridine (DMAP), zinc acetate (ZnOAc) 2 , and bismuth neodecanoate (Bi(neo) 3 ). PHU networks were extensively characterized by thermomechanical analysis (TGA, DSC, DMA, tensile testing), rheological measurements (stress relaxation and small amplitude oscillatory shear), infrared spectroscopy, swelling experiments, and reprocessing tests. Among the catalysts evaluated in this study, the PHU network prepared using potassium methoxide exhibited the best overall performance, combining superior mechanical properties with good reprocessability (up to three cycles), even at a low catalyst loading (2.5 mol%).

Macro-monomer (macromer) containing eight epoxy groups (SU-8), which is known as a photoresist for photolithography, was synthesized and subsequently converted into a series of epoxy-methacrylate macromers via epoxy ring opening with 2-hydroxyethyl methacrylate (HEMA). The resulting macromers were employed in 3D printing resin formulations. The epoxy to methacrylate conversion was confirmed using proton nuclear magnetic resonance (1HNMR) spectroscopy, Fourier Transform Infrared (FTIR) Spectroscopy, and titration. The glass transition temperature (Tg) increased from −25.7 to 12.5 °C with increasing methacrylate content, as determined by differential scanning calorimetry (DSC). Thermogravimetric analysis (TGA) demonstrated a decrease in thermal stability as the methacrylate functionality increased, with the fully methacrylated macromer (FA) losing up to 62% of its weight between 150 and 330 °C. For the study of the photocuring kinetics, ultraviolet (UV)-FTIR, along with the mechanical properties, demonstrated improved curing rate, higher volumetric shrinkage, and enhanced mechanical performance with increasing methacrylation, indicating optimized performance for vat photopolymerization-based 3D printing.

Nature offers numerous examples of materials with extraordinary and multifaceted properties, like combined self-healing, stimuli-responsiveness, and luminescence. Inspired by such designs, chemists have tried to mimic such versatile properties by combining complex polymeric structures reinforced by supramolecular interactions, allowing them to perform multiple functions across various time and length scales. Among these efforts, metal coordination has emerged as a powerful tool to create dynamic, tunable systems. This review explores such innovative approaches in designing luminescent metallo-supramolecular polymer networks (MSPNs), which integrate the entanglement of polymer chains with the dynamic luminescent properties of metal–ligand junctions. Classified by the dimensionality of these junctions, from 0D, formed by single metal ion complexes, to 2D metallacycles, and 3D metallacages, MSPNs benefit from diverse functionalities of junctions, featuring the antenna effect in lanthanide-based 0D nodes and aggregation-induced emission (AIE) in 2D and 3D assemblies, on top of organic conjugated structures that can be integrated in the ligand structure. This initiative addresses the fragile nature and limited formability as one of the main classical barriers to commercialize supramolecular coordination complexes (SCCs) for real-life applications. Since developing such polymeric products requires studying material properties on a new range of time and length scales that are less frequently used by classical chemists, there is gap of knowledge that hinders development of such hybrid materials. By exploring the design strategies of this emerging class of materials, and highlighting macromolecular characteristics of such networks, this review seeks to encourage the development of further luminescent networks based on polymeric constitutes, unlocking new possibilities for applications in advanced functional materials. • Overview of luminescent metallo-supramolecular polymer network (MSPN) design. • Classification of MSPNs by metal-ligand junction dimensionality (0D, 2D, 3D). • Antenna effect in 0D lanthanide nodes and AIE in 2D/3D metallacycles/metallacages. • MSPN applications: bioimaging, catalysis, and energy harvesting. • Identifying key features of MSPNs: self-healing and stimuli-responsiveness.