Preparation of Al(OH)3-based layered structural material by shear alignment from aqueous dispersion of colloidal gibbsite platelets

Abstract

Development of the technological and industrial capabilities to obtain hexagonal gibbsite nanoplatelets with a regularly well-defined configuration is an ongoing consideration that has not yet covered a required level of feasible architecture. Here we present a convenient method to synthesize the colloidal gibbsite particles based on a simple hydrothermal process from aluminum alkoxides in weak acid media. These colloids are near-regularly shaped and fairly monodisperse hexagons with an average diameter of 185 nm and a thickness of ~5.3 nm. The aqueous dispersion of gibbsite platelets can be shear-aligned to form highly ordered, continuous films on a substrate by an industrially adaptable method for producing large-area membranes. Overall, the modified synthesis method exhibits an excellent potential for scalable-up production with high quality in various practical applications. The aligned films also have outstanding properties due to the self-assemblies and interfacial physical interactions between adjacent gibbsite platelets and the possibility of industrial fabrication from those layered structural materials. Moreover, we prepare this shear-aligned membrane by the in-plane shearing method to introduce the great promise of disk-like-derived gibbsite as new gas-barrier material or surface-protective materials.