Biotemplating of inorganic functional materials from polysaccharides

Biomacromolecules control and direct the formation of biominerals and hard tissues in nature. In many cases, polysaccharides are involved during the assembly of the inorganic phase as template. Natural and regenerated polysaccharides exhibit a hierarchical multiscale order as well as self-assembly properties and they appear in a large variety of accessible structures. Therefore, the application of polysaccharide-based structures and composites is a promising approach for the formation of patterned and hierarchically structured inorganic functional and structural materials. The authors report on recent advancements on the biotemplated formation of inorganic functional materials using polysaccharides. Owing to their structural diversity, polysaccharides can be used at various levels from the molecular scale up to complex three-dimensional parts. The versatility of polysaccharide templating is shown on onedimensional (1D) cellulose nanocrystals for formation of inorganic nanotubes. Two-dimensional (2D) Langmuir-Blodgett fi lms of cellulose and cellulose derivatives are used as reference templates to investigate the mineralization behaviour of inorganic phases from supersaturated solutions. The development of optical and photocatalytic materials from plant tissues (wood and Juncaceae) is presented. In innovative route, phototactic microalgae are used as biotemplates for the mineralization of inorganic phases on their exopolysaccharides, which provide novel pathways for the fabrication of a variety of functional materials.