Chem. J. Chinese Universities ›› 2017, Vol. 38 ›› Issue (10): 1850.doi: 10.7503/cjcu20170058

• Physical Chemistry • Previous Articles     Next Articles

Precursors Structural Design and Property of Carbon Membrane for CO2 Capture

SONG Jing1, LI Lin1,*(), LU Yunhua1,2, XU Ruisong1, JIN Xin1, WANG Chunlei1, WANG Tonghua1,*()   

  1. 1. Carbon Research Lab, State Key Lab of Fine Chemicals, School of Chemical Engineering,Dalian University of Technology, Dalian 116024, China
    2. School of Chemical Engineering, University of Science and Technology Liaoning, Anshan 114051, China
  • Received:2017-01-23 Online:2017-10-10 Published:2017-09-22
  • Contact: LI Lin,WANG Tonghua E-mail:lilin121@dlut.edu.cn;wangth@dlut.edu.cn
  • Supported by:
    † Supported by the National Natural Science Foundation of China(Nos.214360092, 21376037, 21406102, 21576035, 21506020), the Fundamental Research Funds for the Central Universities, China[No.DUT16RC(4)05] and the China Postdoctoral Science Foundation(No.2014M561232)

Abstract:

A series of novel polyimide precursors with rigidity and high free volume was designed and synthesized for the preparation of carbon membranes. The pyrolytic characteristics of polyimides and chemical structures and microstructures of derived carbon membranes were characterized by means of thermogravimetric analysis(TG), Fourier transform infrared spectroscopy(FTIR), X-ray diffraction(XRD) and high-resolution transmission electron microscopy(HRTEM). The gas separation performance of carbon membranes was evaluated using pure gases H2, O2, N2, CO2 and CH4. The results indicated that space configuration and free volume of polyimide precursors significantly affected the microstructures and gas separation performance of derived carbon membranes. The higher the structure rigidity of polyimide was, the higher its fractional free volume(FFV) was, the microstructure of prepared carbon membrane became looser and ultramicropore size became larger, resulting in the higher gas permeability of carbon membrane. Wherein, introduction of rigid groups such as fluorene, phthalide, hexafluoroisopropyl in polyimides could effectively disrupt the packing between the molecular chains and enhance the FFV of polyimides. The derived carbon membranes with looser microstructures exhibited excellent gas separation performance which surpassed the Robeson upper bond. Especially, the carbon membrane prepared from ortho-hydroxyl functionalized polyimide exhibited the highest gas permeability among the seven carbon membranes, that was 24770 Barrer(1 Barrer≈7.5×10-18 m2·s-1·Pa-1) for CO2, showing an attractive application prospect for the CO2 separation and capture.

Key words: Carbon membrane, Gas separation, Precursor structure, Fractional free volume, Polyimide

CLC Number: 

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