Gravimetric Analysis of the Adsorption and Desorption of CO2 on Amine-Functionalized Mesoporous Silica Mounted on a Microcantilever Array

Abstract

The kinetics of CO2 adsorption and desorption over amine-functionalized mesoporous silica were investigated using silicon microcantilever arrays. Three types of mesoporous silica with different pore sizes were synthesized and functionalized with a variety of amine molecules. After depositing the silica sorbents onto the free end of each cantilever in an array, mass changes due to the adsorption and desorption of CO2 were determined in situ with picogram sensitivity by measuring variations in the cantilever frequencies. The adsorption and desorption kinetics were found to be diffusion-controlled, and the kinetics were accelerated by increasing the temperature and pore size. The activation energies for adsorption and desorption of CO2 were determined from Arrhenius plots.