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Indexed by:期刊论文

Date of Publication:2019-09-01

Journal:MICROPOROUS AND MESOPOROUS MATERIALS

Included Journals:SCIE、EI

Volume:285

Page Number:142-149

ISSN No.:1387-1811

Key Words:Polyimide; Carbon membranes; Support; Bentonite; Gas permeation

Abstract: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 O-2 to 78% from compressed air at one time.