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A facile, robust, scalable and eco-friendly route as part of a relatively simple system to prepare polymer capsules has always been desired but remains challenging. Herein, a multifunctional, active, amphiphilic macromolecule, 1,1-diphenylethylene (DPE)-capped hydrolyzed poly(glycidyl methacrylate) (D-PGMA), was found to act as both the surfactant and the initiator in an interfacial emulsion polymerization process for polymer capsules. This simplified the emulsion system to only three components: water, monomer and D-PGMA. The interfacial distribution of amphiphilic D-PGMA and the controlled/living radical polymerization owing to the semi-quinoid structure were synergistically responsible for the formation of polymer capsules. Besides, by employing this method, microcapsules encapsulating phase change materials (PCMs) whose encapsulation ratio could be up to 92% were readily fabricated and possessed large heat storage capability and good thermal stability. We believe that this facile, robust, scalable and eco-friendly method will inspire new strategies for preparing polymeric capsules and will find promising application in the field of energy storage. [ABSTRACT FROM AUTHOR]

Si3N4 saw-tooth nanoribbons (SNSNs) have been synthesized via a novel approach involving a by-product pyrolysis–nitridation process during carbon foam manufacturing at 1450 °C. The SNSNs formed are ribbon shaped, 80–750 nm wide, 70–80 nm thick and several micrometres in length. The process simply involved thermal pyrolysis of a powdered mixture containing carbon foam precursors and silicon powder under flowing high-purity nitrogen. Pyrolysis gases rich in silicon, silicon oxide and active nitrogen vapours promoted the subsequent synthesis of the SNSNs over the outer surface of the carbon foams via a vapour–solid mechanism. The crystal structure, morphology, chemical composition, growth mechanism and photoluminescence (PL) properties have been studied. The infrared adsorption of SNSNs exhibited two absorption bands with all the peaks related to the Si–N bonds of the α-Si3N4 crystalline structure. X-ray photoelectron spectroscopy measurements further confirmed the chemical composition, with minor impurities such as oxygen and carbon. A single nanoribbon has the same width-to-thickness ratio, suggesting a stable morphology resulting from the reduction of the overall surface energy. Intense PL was observed centred at 2.03, 2.48, 2.62, and 3.01 eV, which resulted from the recombination between the intrinsic conduction band edges and silicon dangling bonds with deep-level or trap-level states. [ABSTRACT FROM AUTHOR]