Carbon Molecular Sieve Membranes Derived from Tröger's Base-Based Microporous Polyimide for Gas Separation

Graphical Just touching base : New carbon molecular sieve (CMS) membranes are fabricated with the use of a Tröger's base (TB)-based microporous polyimide as the polymer precursor, and their gas-separation performance is investigated. The comprehensive gas-separation performance of the TB–CMS membranes is improved relative to that of most state-of-the-art CMS membranes derived from common polyimides reported so far. Carbon molecular sieve (CMS)-based membranes have attracted great attention because of their outstanding gas-separation performance. The polymer precursor is a key point for the preparation of high-performance CMS membranes. In this work, a microporous polyimide precursor containing a Tröger's base unit was used for the first time to prepare CMS membranes. By optimizing the pyrolysis procedure and the soaking temperature, three TB–CMS membranes were obtained. Gas-permeation tests revealed that the comprehensive gas-separation performance of the TB–CMS membranes was greatly enhanced relative to that of most state-of-the-art CMS membranes derived from polyimides reported so far.