Preparation of novel hydrophilic microporous material PML-1 membrane by topotactic transformation of layered silicate SSA-1 and applicability to the dehydration of aqueous acetic acid

摘要

Novel hydrophilic PML-1 (PML: porous material transformed from a layered silicate) membranes were prepared on a porous tubular alpha-alumina support by a calcination-driven topotactic transformation of a hydrothermally pre-coated layered silicate SSA-1 (SSA: silicate synthesized with a quaternary amine) layer. The effects of seed crystal, synthesis time, and repetitive synthesis on the formation and morphologies of the supported layered silicate layers and corresponding membranes were investigated in detail to reveal that repetitive synthesis allowed the preparation of a dense and continuous layered silicate layer. The performance of the PML-1 membrane with an approximately 6-m-thick separation layer for the pervaporation dehydration of aqueous acetic acid was examined, and the observed water-selective permeability was ascribed to the presence of numerous residual silanol groups in the membrane framework. These results indicate that the prepared PML-1 membrane is applicable to the separation of water/acetic acid mixtures and hence, provide a new approach to the further development and application of layered silicates as novel membrane materials.