CHITIN LIQUID CRYSTAL- DERIVED SPONGE- LIKE AEROGEL

Abstract

Abstract: Chitin nanocrystals in anisotropic liquid crystals have been used as a colloidal precursor to fabricate hydrogels and aerogels. Native chitin nanofibrils are deacetylated and hydrolyzed to generate rod-shaped chitin nanocrystals that are dispersible in water to form colloidal aqueous suspensions. Chitin nanocolloids self-organize into anisotropic liquid crystals that can solidify into layered nematic films. Chitin liquid crystals are hydrothermally gelatinized with formaldehyde crosslinkers to form homogeneous chitin hydrogels. The removal of water in the hydrogels by freeze-drying recovers ultralight chitin sponge-like aerogels with morphological retention of layered nematic chitin structure. These biocompatible chitin aerogels hold promise for developing advanced functional materials such as fabrics for antibacterial bandages and tissue engineering and hydrophobic absorbents for oil/water separation. Potentially, chitin nanocrystals assembled in the aerogels may be functionalized into hydrophobic sponges for oil/water separation or carbonized into nitrogen-doped carbon foams for supercapacitors.