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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 one-dimensional (1D) cellulose nanocrystals for formation of inorganic nanotubes. Two-dimensional (2D) Langmuir–Blodgett films 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.

Nickel acetate doped poly(methylphenylsilsesquioxane) with and without silicon filler loading was pyrolysed in argon atmosphere between 800 and 1500 °C. The ceramic residues were investigated with specific view of the nanoaggregates formed in pores during the polymer‐to‐ceramic conversion. After pyrolysis at 900 °C carbon nanotubes as well as nanowires with a crystalline SiC core and an amorphous SiO2 shell were found in Si filler‐free and Si filler‐loaded samples, respectively. The evolution of the microstructure and the composition of these carbon nanotubes and SiC/SiO2 nanowires were studied by HREM, SEM, EELS, EFTEM and evolved gas analysis. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Thin‐walled (wall thickness, 100–2000 μm) mono‐ and bilayered ceramic tubes in the system Si–O–C–(N) were obtained by centrifugal casting of a polysiloxane/filler suspension. Si and SiC powders were dispersed in polyorganosiloxane/triethoxysilane solutions. After centrifugal casting in a Teflon tube with a rotational speed of 2000 rpm and subsequent cross‐linking at 130°C and 60 rpm, the tubes were pyrolyzed in argon or in nitrogen at 1400–1600°C. Bilayered tubes with controlled variation of porosity were obtained by overcasting the monolayer green tubes with a modified slurry composition.