Synthesis and characterization of amine-modified spherical nanocellulose aerogels

In this work, cellulose nanocrystal (CNC) was prepared from microcrystalline cellulose (MCC) by acid hydrolysis method. The N-(2-aminoethyl)(3-aminopropyl) methyldimethoxysilane (AEAPMDS)-CNC aerogel was successfully fabricated either by freeze-drying or supercritical CO2 drying of spherical CNC hydrogels into which the amine group has been successfully introduced via C-O-Si bonds between CNC and AEAPMDS. The impact of various parameters (time, temperature, AEAPMDS amount, solid-to-liquid ratio) on the properties of the as-prepared materials is systematically explored, revealing the optimum reaction conditions (100 A degrees C, 16 h, solid-to-liquid ratio of 1:10). The as-prepared spherical nanocellulose aerogels were characterized with respect to textural, structural, thermal and morphological characteristics by various methods (BET, XRD, SEM, TGA, FTIR, and NMR). They exhibited a nano-porous network structure of mesopores possessing a high surface area (262 m(2)/g) in the case of supercritical CO2 drying, whereas a honeycomb structure comprising squares, polygons and circles with a surface area of 120.4 m(2)/g was obtained by freeze-drying. The as-synthesized AEAPMDS-CNC aerogels could be potentially applied to capture CO2 via covalent bonding.