The positive/negative effects of bentonite on O2/N2 permeation of carbon molecular sieving membranes
writer：Zhang B, Yang C, Liu S, Wu Y, Wang T, Qiu J.
keywords：gas separation, carbon membranes
source：期刊
specific source：Micropor Mesopor Mat
Issue time：2019年
In this work, bentonite (BT) was first developed as additives to modify carbon molecular sieving (CMS) membranes. The membrane samples were characterized by the techniques of thermogravimetric analysis, differential scanning calorimetry, infrared spectroscopy, X-ray diffraction, nitrogen adsorption, scanning electron microscope and transmission electron microscopy. The effects of BT amount, transmembrane pressure and permeation temperature on the microstructure and gas permeation of CMS membranes were investigated. It finds that the incorporation of BT improves the thermal stability of precursors and the microporous volume of CMS membranes. The graphitization degree and structural compactness of the CMS membranes increase with elevating the BT amount. At the same time, the gas permeability first increases then decreases. In comparison, BT-doped CMS membranes are more permeable for oxygen and nitrogen. Moreover, the permeability of CMS membranes increases by rising permeation temperature or reducing transmembrane pressure. The CMS membranes can directly enrich the mole fraction of O2 to 78% from compressed air at one time.