中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 13 No. 1 February 2003 |
（1. College of Science, Civil Aviation University of China, Tianjin 300300, China;
2. Materials Chemistry Laboratory, Nanjing University of Science and
Technology, Nanjing 210094, China;
3. Institute of Geology, Central South University, Changsha 410083, China）
Abstract:To deal with the brittleness and crystal grain interfacial defects of zeolite membranes, and to confine the pore size distribution of inorganic membranes in a limited range, a process method for composite membranes of A-type zeolite/SiO2 was discribed. A silica sol was mixed with nanocrystals of zeolite 4A in a suitable proportion, then the supported membranes was prepared by dip-coating method. The composite membranes prepared in first step was treated hydrothermally again, so nanocrystal zeolite 4A formed and located in the mesopores of the membranes, and the microstructure and pore size distribution of the membrane were modified greatly. The thermal stability, mineral phase, microstructure, and pore size distribution were examined via DTA-TG, X-ray diffractometer, scanning electron microscope (SEM), and BET equipment. The structure of the composite membranes remains high stability below 800℃. Its average pore size in a very limited range is smaller than that in the untreated membranes in hydrothermal condition, and the peak bands of the membrane pores are 4×10-10m, 1.8×10-9m, respectively.
Key words: 4A; SiO2; composite membrane; zeolite sol-gel; molecular sieving
