Surface modifications of nanofillers for carbon dioxide separation nanocomposite membrane

CO₂ separation is an important process for a wide spectrum of industries including petrochemical, refinery and coal-fired power plant industries. The membrane-based process is a promising operation for CO₂ separation owing to its fundamental engineering and economic benefits over the conventionally used separation processes. Asymmetric polymer-inorganic nanocomposite membranes are endowed with interesting properties for gas separation processes. The presence of nanosized inorganic nanofiller has offered unprecedented opportunities to address the issues of conventionally used polymeric membranes. Surface modification of nanofillers has become an important strategy to address the shortcomings of nanocomposite membranes in terms of nanofiller agglomeration and poor dispersion and polymer-nanofiller incompatibility. In the context of CO₂ gas separation, surface modification of nanofiller is also accomplished to render additional CO₂ sorption capacity and facilitated transport properties. This article focuses on the current strategies employed for the surface modification of nanofillers used in the development of CO₂ separation nanocomposite membranes. A review based on the recent progresses made in physical and chemical modifications of nanofiller using various techniques and modifying agents is presented. The effectiveness of each strategy and the correlation between the surface modified nanofiller and the CO₂ separation performance of the resultant nanocomposite membranes are thoroughly discussed.