5 - Carbon nanotubes-polymer nanocomposite membranes for pervaporation

Abstract

Pervaporation (PV) is a membrane separation technology with high selectivity, efficiency, and energy-saving benefit, especially in separating azeotropic and close boiling point mixtures. Recently polymer nanocomposite membranes have been developed for various PV applications such as dehydration of organic solvents and alcohols, separation of organic–organic mixtures, and recovery of organics from aqueous solutions. In recent years, carbon nanotubes (CNTs) have been identified as a new type of nanofillers for fabrication of new polymer nanocomposite membranes due to their unique structural and extraordinary physical and chemical properties. Significant properties of CNTs, which make them attractive for membrane preparation, are high aspect ratio, small dimensions, high surface area, tubular structure, and remarkable smoothness of their interior graphitic walls. Uniform dispersion of CNTs with agglomeration tendency in polymer matrix is a critical issue in fabrication of CNTs-polymer nanocomposite membranes. Therefore CNTs functionalization with specific functional moieties is necessary to reduce the van der Waals forces between CNTs and improve CNTs dispersion in polymer matrix. In this chapter, current progresses in preparation and characterization of CNTs-polymer nanocomposite membranes for PV applications are being reviewed.