Mesoporous silica and organosilica films templated by nanocrystalline chitin

Abstract

Liquid crystalline phases can be used to impart order into inorganic solids, creating materials that mimic natural architectures. Herein, mesoporous silica and organosilica films with layered structures and high surface areas have been templated by nanocrystalline chitin. Aqueous suspensions of spindle-shaped chitin nanocrystals were prepared by sequential deacetylation and hydrolysis of chitin fibrils isolated from king crab shells. The nanocrystalline chitin self-assembles into a nematic liquid-crystalline phase that has been used to template silica and organosilica composites. Removal of the chitin template by either calcination or sulfuric-acid-catalyzed hydrolysis gave mesoporous silica and ethylene-bridged organosilica films. The large, crack-free mesoporous films have layered structures with features that originate from the nematic organization of the nanocrystalline chitin. Organized nanomaterials: Nanocrystalline chitin (NCh) prepared by sequential deacetylation and hydrolysis of chitin fibrils isolated from king crab shells has been used to template mesoporous silica and organosilica (see figure). The large, crack-free films accurately replicate the organization of the NCh films originating from a transcription of the layered nematic phase of NCh. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.