| abstract |
The present invention describes a composition and a method for producing mesoporous silica materials with a chiral organization. In the method, a polymerizable inorganic monomer is reacted in the presence of nanocrystalline cellulose (NCC) to give a material of inorganic solid with cellulose nanocrystallites embedded in a chiral nematic organization. The NCC can be removed to give a stable porous structure that retains the chiral organization of the NCC template. The new materials may be obtained as iridescent free-standing films with high surface area. Through control of the reaction conditions, the colour of the films can be varied across the entire visible spectrum. These are the first materials to combine mesoporosity with long-range chiral ordering that leads to photonic properties. Examples of possible applications of the materials are: lightweight reinforcement materials, low k dielectric materials, tunable reflective filters, adsorbents, stationary phases for chromatography of chiral or achiral substances, supports for catalysts (e.g., for asymmetric synthetic transformations), and as a template to generate other new porous materials (e.g., porous carbon or porous metals), preferably with chiral nematic structures. |