PNNL

Abstract

Silica-organic composites are receiving renewed attention for their versatility and environmentally benign compositions. Of particular interest is how macromolecules interact with silica to produce functional materials that confer remarkable physical properties to living organisms. This review first examines silicification in organisms and the biomacromolecule properties proposed to modulate these reactions. We then highlight findings from experimental silicification studies organized by major classes of biomacromolecules. Most investigations are qualitative, using disparate experimental and analytical methods, and minimally characterized materials. Many findings are contradictory and, altogether, demonstrate a consistent picture of biomacromolecule-Si interactions has not emerged. Recent advances in biopolymer derivatization present opportunities for hypothesis-based studies that use quantitative experimental methods to decipher how macromolecule functional group chemistry and configuration influence thermodynamic and kinetic barriers to silicification. By harnessing silica-macromolecule interactions, the resulting biocomposites will hold promise for specialized applications from biomedical and clean energy to other materials-dependent industries.