High-performance multi-layer composite membrane with enhanced interlayer compatibility and surface crosslinking for CO2 separation

Preparation of CO 2 separation membrane with high gas permeance and CO 2 selectivity is always desirable. In this work, inspired by pesticides and cosmetics, through the use of a variety of additives, good compatibility between the water-based coating solution of low concentration and the hydrophobic surface of the intermediate layer (or gutter layer) had been achieved. A membrane with high gas permeance and moderate CO 2 selectivity was prepared preliminarily, and the synergistic mechanism among various additives was clarified. Then, through simple cross-linking modification of the membrane surface, a multi-layer composite membrane for CO 2 separation was prepared with CO 2 selectivity being improved greatly. The degree of cross-linking on the membrane surface and the thickness of the cross-linked layer was studied by XPS etching analysis. Separation performance for CO 2 /N 2 , CO 2 /CH 4 , and CO 2 /H 2 mixture had been tested, and the prepared multi-layer composite membrane exhibited excellent CO 2 separation performance. Moreover, the simulated flue gas test showed that the prepared membrane was of good long-term stability and impurity resistance.