Role of amine type in CO₂ separation performance within amine functionalized silica/organosilica membranes: A review

Various types of amine-functionalized silica/organosilica membranes have been developed due to their potentially superior CO₂ separation performance. This article reviews the progress made in this field and special attention is paid to elucidating the role of amine type in CO₂ separation performance within amine-functionalized silica/organosilica membranes. This review includes a systematic comparison of various organosilica membranes with either unhindered or sterically hindered amines developed in our previous studies. Herein, we thoroughly discuss the structural characterizations and CO₂ adsorption/desorption properties of amine-functionalized xerogel powders and CO₂ transport/separation performance across the relevant membranes. Future directions for the design and development of high-performance CO₂ separation membranes are suggested, and particular attention is paid to the future of activation energies for gas permeation.