2006 Volume 114 Issue 1335 Pages 929-933
The mechanical property and gas permeance of α-alumina (Al2O3) porous capillaries fabricated by a dry-wet spinning method were studied. Weibull analysis could be carried out on the fracture strength. Weibull modulus m and characteristic strength σ0 decreased with an increasing porosity. The parameters of the capillaries agreed with the known value of the ordinary Al2O3 porous material. The helium (He) permeance for 77 capillaries at 298 K was 1.8×10-5 mol m-2 s-1 Pa-1 and deviation of the He permeances were in the narrow range from 1.5×10-5 to 2.1×10-5 mol m-2 s-1 Pa-1. Permeances were proportionate to the exponential of porosity, and the dominant permeation mechanism was considered to be the Knudsen diffusion. The γ-alumina-coated porous α-Al2O3 capillary showed high H2 permeance of 9.73×10-6 mol m-2 s-1 Pa-1 at 873 K. Therefore, the porous α-Al2O3 capillary in this study is a candidate for the support of hydrogen-permselective membrane at elevated temperatures.
