Michael North

The escalating threat of bacterial infections highlights the urgent need for flexible antibacterial biobased resin materials. In this study, castor oil was transformed into imidazole-based ionic liquids (c1 and c2) via a two-step atom-economic synthesis. Thermosetting resins were fabricated through UV-thermal dual-cured thiol-ene click polymerization of c1/c2 with multifunctional thiol monomers. A biobased aromatic α,ω-diene carbonate monomer (d) was introduced to modulate the network structure. Thermal curing behavior was optimized by using NMR and FTIR analyses. Tensile testing identified Pc1₁d₉-4SH and Pc2₁d₉-4SH as optimal formulations, exhibiting tensile strengths of 9.42 and 9.08 MPa, elongation at break of 279.9% and 280.0%, and a glass transition temperature around 15 °C. DMA and TGA confirmed their viscoelastic behavior and thermal stability, while AFM/SEM revealed phase-separated microstructures contributing to enhanced mechanical properties. Antibacterial tests demonstrated exceptional efficacy (99.9% inhibition) against common pathogens. By integrating molecular design and process innovation, this work establishes a biobased resin system combining flexibility, thermal stability, and potent antibacterial activity, offering a novel strategy for developing infection-resistant biomedical materials.

The continuous rise in global population and rapid economic growth have led to excessive consumption of nonrenewable resources and severe environmental pollution. Consequently, increasing efforts have been directed toward reducing the dependence on these resources and promoting the development of renewable alternatives. In this study, we proposed an effective strategy for utilizing keratin derived from waste textiles as a potential feedstock for producing value-added materials. The distinctive chemical structure of wool keratin, characterized by a high content of cysteine residues with thiol groups, enables its strong selective anchoring ability for gold nanoparticles (AuNPs). This property suggests that the wool keratin-based regenerated hydrogels can be applied as ideal supports for AuNPs immobilization. Accordingly, a series of cellulose/wool keratin composite hydrogels were synthesized and employed as supports for AuNPs, which were formed by reducing selectively absorbed Au³⁺ ions using sodium borohydride (NaBH₄). Structural and morphological analyses confirmed the uniform distribution of anchored AuNPs with an average diameter of approximately 3.74 nm. These composite hydrogels exhibited good catalytic activity in the reduction of 4-nitrophenol (4-NP) and demonstrated remarkable reusability, maintaining catalytic efficiency over 10 cycles. In the presence of C50W50@Au, the activation parameters for the 4-NP reduction were determined as E_a = 11.320 kJ mol^-1, ΔH^# = 8.729 kJ mol^-1, and ΔS^# = 50.106 kJ mol^-1 K^-1. Thus, this work focused on the high-value applications of wool keratin waste and presents a stable and efficient precious-metal nanoparticle catalyst for aqueous-phase catalysis.

A 4 Å zeolite prepared under the synergistic effect of intense ultrasound and a high-voltage electrostatic field had an octahedral structure rather than a conventional hexahedral structure. XPS and XRD analyses showed that the ratio of silicon to aluminum, 2θ peak position, and the corresponding crystal planes were the same as those in traditional hexahedral 4 Å zeolite, but some crystal planes were more prominent. SEM imaging showed that the octahedral zeolites had a larger particle size. Porosimetry (BET surface area and BJH analysis) showed that the octahedral zeolite had become a mesoporous zeolite, and its specific surface area increased and its pore size expanded, which was conducive to loading catalytically active materials and thus improving its catalytic performance. In this paper, the mechanism of formation of hierarchical LTA zeolite is discussed, and the octahedral hierarchical LTA zeolite is used to catalyze the epoxidation of styrene, giving very good results. It is concluded that the (600), (622), (642), and (644) crystal planes played a decisive role in the styrene epoxidation reaction, providing a realistic basis for explaining the crystal plane catalysis effect of the 4 Å zeolite. This new zeolite prepared under the synergistic effect of intense ultrasound and a high-voltage electrostatic field, being the first time to prepare the octahedral hierarchical LTA zeolite, is simple to produce, green, and environmentally friendly and has good economic development prospects compared to the use of templating agents, which not only provides ideas and simpler methods for optimizing the performance of traditional zeolites and developing new zeolites with better performance but also enhances the theoretical basis for preparing new zeolites.

The regioselective synthesis of carbamates from bio‐derived cyclic carbonates and amines by using 1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene (TBD) as an organocatalyst is reported. This methodology led to the preparation of a wide range of bio‐sourced hydroxyurethanes from furan‐, carvone‐ and limonene‐based scaffolds under solvent‐free and mild reaction conditions. Moreover, a comprehensive analysis of the process allowed us to optimize the catalyst loading with little or no impact on the process regioselectivity.

Nonisocyanate polyurethanes (NIPUs) are considered greener alternatives to traditional polyurethanes, and the preparation of NIPUs considerably depends on the design and synthesis of suitable monomers. Herein, we propose a toolbox for in situ capturing and conversion of CO₂ into α,ω-diene-functionalized carbamate monomers by taking advantage of the facile reversible reaction of CO₂ with diamines in the presence of organic superbases. The activation of CO₂ into carbamate intermedia was demonstrated by NMR and in situ FTIR, and the optimal conditions to prepare α,ω-diene-functionalized carbamate monomers were established. Thiol-ene and acyclic diene metathesis (ADMET) polymerization of these monomers under mild conditions yielded a series of poly(thioether urethane)s and unsaturated aromatic-aliphatic polyurethanes with high yield and glass transition temperatures ranging from -26.8 to -1.1 °C. These obtained NIPUs could be further modified via postpolymerization oxidation or hydrogenation to yield poly(sulfone urethane) and saturated polyurethane with tunable properties.

Five nitrogen sources (glycine, β‐alanine, urea, melamine and nicotinamide) and three heating methods (thermal, monomodal microwave and multimodal microwave) are used to prepare nitrogen‐doped Starbons® derived from starch. The materials are initially produced at 250–300 °C (SN_x300_y), then heated in vacuo to 800 °C to produce nitrogen‐doped SN_x800_y’s. Melamine gives the highest nitrogen incorporation without destroying the Starbon® pore structure and the microwave heating methods give higher nitrogen incorporations than thermal heating. The carbon dioxide adsorption capacities of the nitrogen‐doped Starbons® determined gravimetrically, in many cases exceed those of S300 and S800. The carbon dioxide, nitrogen and methane adsorption isotherms of the most promising materials are measured volumetrically. Most of the nitrogen‐doped materials show higher carbon dioxide adsorption capacities than S800, but lower methane and nitrogen adsorption capacities. As a result, the nitrogen‐doped Starbons® exhibit significantly enhanced carbon dioxide versus nitrogen and methane versus nitrogen selectivities compared to S800.

The use of potassium hydroxide activated Starbons® derived from starch and alginic acid as adsorbents for 29 volatile organic compounds (VOCs) was investigated. In every case, the alginic acid derived Starbon (A800K2) was found to be the optimal adsorbent, significantly outperforming both commercial activated carbon and starch derived, activated Starbon (S800K2). The saturated adsorption capacity of A800K2 depends on both the size of the VOC and the functional groups it contains. The highest saturated adsorption capacities were obtained with small VOCs. For VOC's of similar size, the presence of polarizable electrons in lone pairs or π‐bonds within non‐polar VOCs was beneficial. Analysis of porosimetry data suggests that the VOC's are being adsorbed within the pore structure of A800K2 rather than just on its surface. The adsorption was completely reversible by thermal treatment of the saturated Starbon under vacuum.

Epoxidised Brazilian vegetable oils obtained from the baru nut ( Dipteryx alata Vogel ) and the macaw palm ( Acrocomia aculeata ) react with bioderivable anhydrides (succinic, glutaric, itaconic or citraconic) to give highly crosslinked polyesters.

Carbon dioxide (CO₂) occurs naturally, though its emissions have been increasing due to anthropogenic activities, and its increasing atmospheric concentration levels are causing a greenhouse effect. In efforts to develop new carbon dioxide utilization (CDU) methodologies, the catalyzed reaction of CO₂ with epoxidized vegetable oil, obtained from Brazilian macaw oil and Baru oil, to form carbonated oils for novel and sustainable monomers was explored. A screening process is carried out to develop the best reaction conditions, by varying catalyst/cocatalyst loading, reaction time, CO₂ pressure, and the reaction temperature, resulting in conversions of 100%. The aluminum(salen) complex shows a selective and efficient catalyst activity. Both carbonated oils are reacted with amines (1,6‐diaminohexane, lysine, and 4,4′‐methylenebis [cyclohexylamine]) to provide weldable polyhydroxyurethanes. Polymers synthesized from lysine provide a more selective reaction and higher cross‐linked structures, with fewer side reactions involving the glyceride groups. All the synthesized polymers are thermally stable above 200°C and differential scanning calorimetry (DSC) analysis shows two main thermal events, related to the glass transition (T_g) and the topology‐freezing transition temperature (T_v). The T_v result indicates that the polymer has weldable properties due to chemical bond exchange. Thus, these polymers can be healed into different shapes upon exposure to red light (660 nm).