SCI和EI收录∣中国化工学会会刊

›› 2010, Vol. 18 ›› Issue (3): 377-383.

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Preparation and Characterization of Alumina Membranes on Capillary Supports:Effect of Film-coating on Crack-free Membrane Preparation

朱瑾, 范益群, 徐南平   

  1. State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing 210009, China
  • 收稿日期:2009-10-26 修回日期:2010-03-31 出版日期:2010-06-28 发布日期:2010-06-28
  • 通讯作者: FAN Yiqun,E-mail:yiqunfan@njut.edu.cn
  • 基金资助:
    Supported by the National High Technology Research and Development Program of China(2007AA030303);the National Basic Research Program of China(2009CB623400);the National Natural Science Foundation of China(20776067)

Preparation and Characterization of Alumina Membranes on Capillary Supports:Effect of Film-coating on Crack-free Membrane Preparation

ZHU Jin, FAN Yiqun, XU Nanping   

  1. State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing 210009, China
  • Received:2009-10-26 Revised:2010-03-31 Online:2010-06-28 Published:2010-06-28
  • Supported by:
    Supported by the National High Technology Research and Development Program of China(2007AA030303);the National Basic Research Program of China(2009CB623400);the National Natural Science Foundation of China(20776067)

摘要: Ceramic capillary membrane has received much attention due to its relatively high pack density and favorable mechanical strength.However,it is difficult to prepare capillary membrane on its thin support by a dip-coating method.In this study,alumina microfiltration membranes were prepared on the inner surface of alumina capillary support(outer diameter 4 mm,inner diameter 2.5 mm)by a dip-coating method.Scanning electron microscopy(SEM)observation,gas bubble pressure(GBP)method and membrane permeation test were carried out to evaluate membrane performance.Two major effects in preparation of crack-free membrane,capillary filtration and film-coating,upon the thin support were studied.The as-prepared crack-free membrane presents a narrow pore size distribution,a mean pore size of about 0.6μm and a high pure water flux of 86000 L·m-2·h-1·MPa.It is proved that the membrane thickness should be sufficiently large to overcome the defects of support surface,but it is only one of the prerequisites for the formation of crack-free membrane.Furthermore,it is demonstrated that the capillary filtration effect is greatly restricted for thin capillary support with the dip-coating method and the film-coating effect plays a crucial role in the formation of crack-free membrane.

关键词: capillary, film coating, dip-coating, ceramic membrane

Abstract: Ceramic capillary membrane has received much attention due to its relatively high pack density and favorable mechanical strength.However,it is difficult to prepare capillary membrane on its thin support by a dip-coating method.In this study,alumina microfiltration membranes were prepared on the inner surface of alumina capillary support(outer diameter 4 mm,inner diameter 2.5 mm)by a dip-coating method.Scanning electron microscopy(SEM)observation,gas bubble pressure(GBP)method and membrane permeation test were carried out to evaluate membrane performance.Two major effects in preparation of crack-free membrane,capillary filtration and film-coating,upon the thin support were studied.The as-prepared crack-free membrane presents a narrow pore size distribution,a mean pore size of about 0.6μm and a high pure water flux of 86000 L·m-2·h-1·MPa.It is proved that the membrane thickness should be sufficiently large to overcome the defects of support surface,but it is only one of the prerequisites for the formation of crack-free membrane.Furthermore,it is demonstrated that the capillary filtration effect is greatly restricted for thin capillary support with the dip-coating method and the film-coating effect plays a crucial role in the formation of crack-free membrane.

Key words: capillary, film coating, dip-coating, ceramic membrane