ABSTRACT
The gas separation characteristics of ultramicroporous glass capillary membranes were investigated. Glass capillary membranes which had ultramicropores (pore diameter less than 1 nm) were prepared by elution of alkali metal ions from glass capillaries. It was found from elution treatment that alkali metal ions of 3 Na(composition: 778 SiO2, 22 Na2O mol%) and 3 K (composition: 77 SiO2, 22 K2O mol%) glass capillaries were completely eluted after 90 and 10 minutes with 3 mol/L HNO3, 240 and 10 minutes with 3 mol/L CHM3COOH and 3 mol/L H3PO4, respectively. Permeations of N2, He, and CO2 were measured at 298, 373, and 473 K. Permeation rates of the 3 Na and 3 K glass capillary membranes were 11 (cm3(STP).cm2-s1.cmHg1). The ratios of permeation rates, CO2/N2 and He/N2, were similar to the theoretical Knudsen values.