Silica nanocasting of simple cellulose derivatives: Towards chiral pore systems with long-range order and chiral optical coatings

Aqeous solutions of hydroxypropyl cellulose with cholesteric superstructures were employed as templates in a silica nanocasting process, and the resulting pore structures were characterized by polarization microscopy, circular dichroism, X-ray scattering, transmission electron microscopy, and sorption measurements.Whereas the local pore architecture corresponds to a cast of single cellulose strands and their statistical aggregates, the averaged structure on larger scales keeps the cholesteric character, with the cholesteric pitch just slightly shortened.