The Microstructure of Glass

Stryjak and McMillan (1978) demonstrated increased hardness of the recrystallized material (Table 5.9), testing the properties of spinel glass-ceramics from the Zn0-Al203-Si02 system, with Zr02 admixture as the crystallization nucleator, in combination with the microstructure of glasses... 

The microstructure of glasses in the system Ba0-Si02 can be determined using transmission electron miaos-copy (TEM). We find the following ... 

Figure 5.14 The microstructure of the set cement is clearly revealed by Nomarski reflectance optical microscopy. Glass particles are distinguished from the matrix by the presence of etched circular areas at the site of the phase-separated droplets (Barry, Clinton Wilson, 1979).

The sol-gel process to prepare SIO2 glass fibers and T102 films has been reviewed. It has been known that the hydrolysis conditions such as molar ratio of water to alkoxide and reaction temperature are critical to the desired forms of the gel product (fiber, film or bulk). Some properties of the resultant products have been examined. Especially, Ti02 films have been attempted to use as a photoanode for decomposition of water, and their photoelectrochemical properties are described in comparison with the results previously obtained for single crystal and polycrystalline TiC>2, and are discussed in terms of the microstructure of the film. 

The phase structure of glasses has a significant effect on their physical properties, which is discussed below with reference to chemical durability. The magnitude of the phase separation can be altered by heat treatment, and enhanced or reduced by the addition of various oxides to the melt. In particular, the addition of alumina to commercial soda-lime-silica glasses reduces the tendency to phase separation, improving chemical resistance (Doremus, 1973). A detailed study of the microstructure of soda-lime-silica glasses has been published by Burnett and Douglas (1970). The control of phase separation in the melt is now commercially important for processes such as the... 

Porai-Koshits, I. A., Golubkov, V. V., Titov, A. P. Vasilevskaya, T. N. 1982, The microstructure of some glasses and melts. Journal of Non-Crystalline Solids, 49, 143-156. 

The Metravib Micromecanalyser is an inverted torsional pendulum, but unlike the torsional pendulums described earlier, it can be operated as a forced-vibration instrument. It is fully computerized and automatically determines G y G"y and tan 8 as a function of temperature at low frequencies (10-5 1 Hz). Stress relaxation and creep measurements are also possible. The temperature range is —170 to 400°C. The Micromecanalyser probably has been used more for the characterization of glasses and metals than for polymers, but has proved useful for determining glassy-state relaxations and microstructures of polymer blends (285) and latex films (286). 

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