Tunable amine loading of amine grafted mesoporous silica grafted at room temperature: Applications for CO2 capture

SBA-15 was employed to study amine-grafting in dry and wet grafting conditions at low temperature. SBA-15 was amine-grafted at 30 degrees C and for contrast SBA-15 was conventionally grafted at 85 degrees C to determine how amine-grafting at 30 degrees C affects amine-grafting outcomes. It was found that under dry grafting conditions, adsorbents grafted at 30 and 85 degrees C exhibited similar amine loadings. It was also found that when water was added during grafting, adsorbents grafted at 30 degrees C displayed higher amine loadings than those at 85 degrees C. At 30 degrees C, more water can occupy the pore space of the SBA-15 prior to clogging of the pores, resulting in higher amine loading. This results in higher CO2 capacities at 75 degrees C for adsorbents grafted at 30 degrees C. The stability of materials grafted at 30 degrees C and the universality of the studied effects for other aminosilanes and mesoporous silica supports were demonstrated. (c) 2022 Published by Elsevier Ltd.

Automated summary

It was found that amine-grafting at low temperature can result in higher amine loadings, especially under wet grafting conditions. This is because more water occupies the pore space at lower temperatures, leading to higher amine loadings.