Silica Nanocasting of Simple Cellulose Derivatives: Towards Chiral Pore Systems with Long‐Range Order and Chiral Optical Coatings

Abstract

Aqueous 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.

Synthesis and characterization of guar gum templated hybrid nano silica

“…Polysaccharide self-assemblies are capable of templating novel mesophasic inorganic materials [19]. Templating techniques have been used to control the structural properties of materials including outer shape, inner porosity, and surface area [20] such as the fibrous superstructure of collagen was used to produce tubular silica [21], cellulose [22], and its derivatives [23,24] and dextran-based polymers [25,26] have resulted in both meso-and macroscopic porous inorganic structures; and ␣-chitin [27] and starch [28] gave large scale sponge-like architecture to the final silica or silicalite materials.…”

Template‐Free Tuning of Nanopores in Carbonaceous Polymers through Ionothermal Synthesis

“…[5][6][7][8][9][10][11][12] It is, however, much more difficult to design mesoporous organic materials (i.e., with pores in the range of 2-50 nm). Generally, mesoporous materials such as silica are synthesized through a soft templating approach, [13][14][15][16][17] whereas carbons or polymer networks usually require the use of silica-based hard templates, [1,[18][19][20] but some reports with a soft templating approach were recently reported as well. [21][22][23] Although this methodology led to interesting materials, it is practically a ''no-go'' for industrial applications because of its complexity and high cost.…”

Liquid Crystals of Cellulosics: Fascinating Ordered Structures for the Design of Functional Material Systems

“…Concerning silica hybridization (Fig. 15b), as briefly reviewed [10], an earlier report by Thomas and Antonietti [75] included an iridescently colored hybrid material of HPC/silica produced by sol-gel conversion of tetramethyl orthosilicate (TMOS), used as a solvent component of aqueous lyotropics of HPC. The hybrid was further transformed into silica glass retaining a chiral nematic pore structure by post-treatment of calcination to remove the organic template.…”