Compression silica glass

A sample cell was designed to accomodate supercritical fluids at high pressures up to 20 MPa and at moderate temperatures using stainless steel and fused silica glass, as schematically shown in Fig. 1. The fluid was prepared by compressing the low pressure sample gas from the tube using a piston compressor outside the cell. The cell and the attached part for high pressure lines were immersed in an air thermostat. The pressure and temperature were... 

Fig. 49. Raman spectra of silica glass upon quasihydrostatic compression. The defect bands are marked Dj and D2. Data from Reference [21].

The extrapolation of the composite aerogel compression curve leads to the conclusion that fully dense silica glass could be achieved in the pressiure range of400-500 MPa. 

The temperature of ignition of a mixture fired by adiabatic compression Is lower than when the same mixture is fired by being heated in a glass or silica tube at atmospheric pressure. Professor H B. Dixon in a private communication to the author states that he found the ignition temperature of electrolytic gas under the latter conditions to be 580° C. 

Vitreous Silica Vitreous sdica is a glass form of sdica composed of Si02. It may be transparent, translucent, or opaque. It has a number of abnormal and anomalous properties in thermal expansion, viscosity, bulk density, compressibility, and elasticity. These properties depend on thermal history and preparation method. Vitreous sdica exhibits high resistance to chemical attack. At ambient temperature, it is not attacked by any chemical except hydrofluoric acid. 

---