Directed formation of silica by a non-peptideblock copolymer enzyme mimic

Abstract

A non-polypeptide block copolymer inspired by the enzyme silicatein α is shown to template the formation of silica from tetraethoxy orthosilicate (TEOS) in neutral pH and ambient temperature. The block copolymer was synthesized to mimic the chemical functionality shown to be necessary for the function of the natural enzyme. In this report we demonstrate the templating function of the enzyme mimic, the formation of hierarchical structures, the presence of dual mechanisms of condensation at low pH, investigate the mechanism of templation as hydrolyzed species diffuse from the site of hydrolysis, and explore the formation of silica at the polymer surface. Numerous analytical methods are employed in this study, including AFM, TEM, FESEM, DLS, NMR, GPC, and TGA. This bio-inspired polymer combines the features of neutral pH, low temperature, and structure control in silica formation.