Synthesis and Characterization of Amine Impregnated Silica Aerogel from Rice Husk for CO2 Adsorption
Abstract: Rice husk has attracted considerable attention in the recent years due to its chemical component that are beneficial to a wide range of application. . In this paper, silica aerogel from rice husk ash (RHA) was prepared through sol-gel processing and ambient pressure drying. The silica RHA was extracted with sodium hydroxide solution to produce sodium silicate solution and neutralized with sulphuric acid to form silica gel. Then, the silica aerogel was further modified with amine, which is 3-(aminopropyl) triethoxysilane (APTES) because amine groups provide specific adsorption sides for CO2 adsorption. The functional group, surface morphology and elemental composition of rice husk, silica aerogel and modified silica aerogel were characterized by Fourier transform infrared spectroscopy (FTIR), Scanning Electronic Microscopy (SEM) and Elemental analyser (EA). For amine modified silica aerogel, it was found that the sample consists of N-H band at a certain peak. FTIR and SEM analysis revealed the synthesized silica aerogel has fibrous morphology and indicates similar trend with previous researches. The amine modified silica aerogel (AMSA) is able to adsorb 0.88 mol CO2/kg AMSA. This study shows that the rice husk silica aerogel modified with APTES could enhance the CO2 adsorption performance due to the physisorption and chemisorption