Shrinkage of Bismuth-Containing Porous Glass During the Sintering Process and the Viscosity of Quartz-Like Glass Based on Them

Effect of P2O5 Impurities and Fluoride Ions on The Rheological Properties of Porous Glasses and Bismuth-Containing Composites Based on Them

“…When studying shrinkage upon heating of the PG samples made of NFF-I glass, heat-treated at T t.treat. = 120, 600, 650, or 700°C, the same tendency which is characteristic for the shrinkage of PG specimens from basic SBS glass [22,23] was observed. The increase in T t.treat.…”

“…Comparison with the previously obtained data [23] showed that the shrinkage of PG made of NFF-I glass (Fig. 1a) begins at a temperature ~100°C lower than the shrinkage of PG made of 8B-NT glass (D = 4 nm) [20].…”

“…The study of the shrinkage (relative change in linear dimensions ΔL/L 0 ) of the samples and viscosity η during heating was carried out in accordance with the procedure [23] using a KB-1665 vertical quartz viscometer-dilatometer (Russia) with a low measuring force (0.05 N) of the design [24] with automatic recording of the experimental curves at a sample heating rate of 3 K/min from room temperature to ~850°C (sample load 5 g). The regulation and measurement of temperature T were carried out with an accuracy of ±1°C.…”

“…The error in determining the viscosity did not exceed ±0.05 log (η, P). The linear dependences of the logarithm of viscosity on the reciprocal temperature were constructed using the least squares method and approximation by the Frenkel equation similar to the procedure [23].…”

“…It is of interest to study the rheological properties of samples of bismuth-containing porous glasses (BPGs) and sintered quartz-like glass (BQGs) based on SBS glass doped with P 2 O 5 and fluoride ions, in comparison with the samples obtained based on the basic SBS glass [23], to which this paper is devoted.…”