Synthesis of uniform microporous polymernanoparticles and their applications for hydrogenstorage

Abstract

This work is aimed at producing uniform microporous polymer nanoparticles (MPNs) and studying their hydrogen storage properties. Synthesis of vinylbenzyl chloride (VBC)/divinylbenzene (DVB) copolymers by emulsion polymerization yield fairly uniform gel-type precursor nanoparticles and the particle size can be tuned from 36 to 131 nm by adjusting the emulsifier dose. These are analogous to gel-type suspension polymerized particles typically of 10–500 μm in diameter and are essentially non-porous in the dry state having only a very nominal surface area (1–2 m²/g, BET surface area). Friedel–Crafts-type hyper-cross-linking reaction of these precursors yields uniform MPNs with extremely high surface area up to ca. 1500 m²/g (BET surface area). Moreover, MPNs present more micropore volume (0.56 cm³/g), higher hydrogen adsorption capacity (1.59 wt%, 77.3 K, 1.13 bar), higher isosteric heats for hydrogen and faster adsorption rate as compared to polydisperse micro-size analogues previously reported.