CONCLUSION
In summary, this work demonstrated that directional freeze-casting of liquid crystalline CNCs is an ideal method for preparation of a novel anisotropic aerogel that features hierarchical structures and oriented long-range ordering. During the freeze-casting process, the isotropic CNC suspension can be aligned and trapped by the elongation flow of ice crystals, whose orientations can be preserved by sublimation of the ice template. In the case of anisotropic liquid CNC crystals, CNCs assemble with the assistance of ice crystals, with their liquid crystalline ordering then transferred into the subsequent aerogel. These new bio-based aerogels exhibit oriented ordering, anisotropic optical properties and high porosity, that may find applications in high-performance insulators, tissue engineering, catalyst supports and adsorption media.
ASSOCIATED CONTENT