Preparation of an Amine-Modified Cellulose Nanocrystal Aerogel by Chemical Vapor Deposition and Its Application in CO2 Capture

At present, cellulose nanocrystal (CNC) aerogels with high adsorption properties for CO2 are mostly prepared by the liquid phase method which leads to the problem of modifier loss. In this work, a novel amino CNC aerogel was developed by chemical vapor deposition using 3-(2-aminoethylamino)-propylmethyldimethoxy silane (APS) as the modifier, which improved the utilization ratio of the modifier while ensuring the CO2 adsorption performance. Herein, the as-prepared APS-CNC aerogel was characterized with elemental and functional groups and thermal, morphological, and structural characteristics by various measurements (X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy, and Brunauer-Emmet-Teller equation). It exhibited a porous network structure with low specific surface area (29.14 m(2)/g) and excellent thermal stability. Furthermore, the CO2 adsorption capacity of the CNC aerogel grafted with APS reached 1.5034 mmol/g (25 degrees C, 1 bar, and pure dry CO2 atmosphere). Meanwhile, the APS-CNC aerogel showed excellent CO2 adsorption/desorption recyclability after 10 cycles. The experimental results showed that the CNC aerogel modified by chemical vapor deposition had an important potential role as a biomass CO2 solid adsorbent.