Novel nitrogen-rich mesoporous carbon nanospheres (NMCN) with high surface area and ordered pore geometry are prepared via a facile pathway for efficient CO2 capture and contaminant removal applications.
Well-defined fluoropolymers exhibit unique properties such as excellent oil and water repellency, satisfactory thermal stability, low refractive index, and low surface energy.The origin of these properties is attributed to the presence of strong electronegative and low polarizable Fluorine atom in the backbone of such polymers which leads to a strong C F bond (with a high bond dissociation energy of 485 kJ mol −1 ). Due to these features, these polymers have found applications as functional coatings, thermoplastics, biomedical items, separators and binders for Li-ion batteries, fuel cell membranes, piezoelectric devices, high quality wires and cables, etc. Usually, fluoropolymers are synthesized by conventional radical (co)polymerization of fluoroalkenes which leads to the production of (co)polymers with ill-defined end group, uncontrolled molar mass, and high dispersity values. In the last two decades, significant developments of various reversible deactivation radical polymerization (RDRP) techniques have helped the design of macromolecular architectures (including block, graft, star, dendrimers) on demand. However, for relevant new applications, well-defined fluoropolymers with well-defined macromolecular architectures (e.g. block copolymers as thermoplastic elastomers and electroactive polymers or graft copolymers for fuel cell membranes) are required.Several RDRP methods developed in the last couple of decades have paved the way for the synthesis of (co)polymers with well-defined molar mass, dispersity, chain end-functionality and
A novel dual pH/thermoresponsive amphiphilic poly(histidine methacrylamide)-block-hydroxyl-terminated polybutadiene-block-poly(histidine methacrylamide) (PHisMAM-b-PB-b-PHisMAM) triblock copolymer biohybrid, composed of hydrophobic PB and ampholytic PHisMAM segments, is developed via direct switching from living anionic polymerization to recyclable nanoparticle catalyst-mediated reversible-deactivation radical polymerization (RDRP). The transformation involved in situ postpolymerization modification of living polybutadiene-based carbanionic species, end-capped with ethylene oxide, into dihydroxyl-terminated polybutadiene and a subsequent reaction with 2-bromo-2-methylpropionyl bromide resulting in a telechelic ATRP macroinitiator (Br−PB−Br). Br−PB−Br was used to mediate RDRP of an L-histidine-derived monomer, HisMAM, yielding a series of PHisMAM-b-PB-b-PHisMAM triblock copolymers. The copolymer's stimuli response was assessed against pH and temperature changes. The copolymer is capable of switching among its zwitterionic, anionic, and cationic forms and exhibited unique antifouling properties in its zwitterionic form. These novel triblock copolymers are expected to be show promising potential in biomedical applications.
A novel triple stimuli sensitive block copolymer is prepared by magnetically separable and reusable (up to multiple cycles) Ni–Co alloy nanoparticles mediated reversible deactivation radical polymerization (RDRP) at 25 °C, that responds to changes in temperature, pH, and light. Design of this block copolymer constitutes a temperature‐sensitive N‐isopropylacrylamide (NIPAM), an acid‐sensitive lysine methacrylamide (LysMAM), and a light responsive umbelliferone (UMB) end group. The stimuli response, in response to one stimulus as well as combinations of stimuli, has been evaluated. Responsiveness to light allows the construction of self‐healing materials. Density functional theory calculations rationalize the underlying mechanism of the polymerization.
Well-defined functional polyacrylates with dual stimuli response and tunable surface hydrophobicity were synthesized via the recyclable Ni–Co alloy catalyzed reversible deactivation radical polymerization technique at ambient temperature.
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