title: Aerogels with 3D ordered nanofiber skeletons of liquid-crystalline nanocellulose derivatives as tough and transparent insulators.
abstract: Aerogels of high porosity and with a large internal surface area exhibit outstanding performances as thermal, acoustic, or electrical insulators. However, most aerogels are mechanically brittle and optically opaque, and the structural and physical properties of aerogels strongly depend on their densities. The unfavorable characteristics of aerogels are intrinsic to their skeletal structures consisting of randomly interconnected spherical nanoparticles. A structurally new type of aerogel with a three-dimensionally ordered nanofiber skeleton of liquid-crystalline nanocellulose (LC-NCell) is now reported. This LC-NCell material is composed of mechanically strong, surface-carboxylated cellulose nanofibers dispersed in a nematic LC order. The LC-NCell aerogels are transparent and combine mechanical toughness and good insulation properties. These properties of the LC-NCell aerogels could also be readily controlled.
authors.affiliation: Department of Biomaterials Science, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo (Japan).
authors.forename: Yuri
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Tsuguyuki
authors.initials: T
authors.lastname: Saito
authors.forename: Akira
authors.initials: A
authors.lastname: Isogai
mesh_terms: D002384:Catalysis; D002482:Cellulose / Q000737:chemistry*; D003497:Cyclic N-Oxides / Q000737:chemistry; D055119:Elastic Modulus; D005782:Gels / Q000737:chemistry*; D050866:Liquid Crystals / Q000737:chemistry*; D057139:Nanofibers / Q000737:chemistry*; D016062:Porosity; D013499:Surface Properties; D013814:Thermal Conductivity
chemical_list: D003497:Cyclic N-Oxides; D005782:Gels; D002482:Cellulose; C003959:TEMPO
keywords: aerogels; insulation; liquid crystals; mesoporous materials; nanocellulose