Gas transport in vitreous silica fibers

Abstract

Micrometer-scale fibers of vitreous silica were used to extend solubility-based gas transport measurements to lower-temperature ranges and/or gas species larger than helium. The distribution of fiber diameters established a saturation curve for determining diffusivity from time-to-half saturation. Necessary experimental sensitivity was provided by a differential pressure transducer. Good agreement was demonstrated between near room temperature measurements in this study on neon and previous high-temperature studies on millimeter-scale rod and disk specimens. Over the temperature range 0–777°C, the solubility of neon in vitreous silica can be given by S = (6.07×10 22 atoms/(m 3 atm)) exp((+6.70 kJ/g atom/ RT) diffusivity over the range of 0–984°C can be given by D = (0.997×10 −8 m 2/s) exp((−41.0 kJ/g atom)/ RT).