title: Chiral nematic porous germania and germanium/carbon films.
abstract: We report our extensive attempts and, ultimately, success to produce crack-free, chiral nematic GeO2/cellulose nanocrystal (CNC) composite films with tunable photonic properties from the controlled assembly of germanium(iv) alkoxides with the lyotropic liquid-crystalline CNCs in a mixed solvent of water/DMF. With different pyrolysis conditions, the photonic GeO2/CNC composites can be converted into freestanding chiral nematic films of amorphous GeO2, and semiconducting mesoporous GeO2/C and Ge/C replicas. These new materials are promising for chiral separation, enantioselective adsorption, catalysis, sensing, optoelectronics, and lithium ion batteries. Furthermore, the new, reproducible synthesis strategies developed may be applicable for constructing other composites and porous materials with chiral nematic ordering.
authors.affiliation: Department of Material Science and Engineering, College of Aerospace Science and Engineering, National University of Defense Technology (NUDT), Changsha, Hunan 410073, P. R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Xu
authors.forename: Thanh-Dinh
authors.initials: TD
authors.lastname: Nguyen
authors.forename: Kai
authors.initials: K
authors.lastname: Xie
authors.forename: Wadood Y
authors.initials: WY
authors.lastname: Hamad
authors.forename: Mark J
authors.initials: MJ
authors.lastname: MacLachlan