Silico-phosphate glasses

Okura, T. Yamashita, K. (2000). Ionic conductivities of Na+-ion implanted silico-phosphate glass-ceramics. Solid State Ionics, 136-137,1049-1054. 

Traces of unreacted silica (Si02) in the SiC will produce a fluffy white precipitate, about which little is known. Certainly it is known that when hot concentrated phosphoric acid is in contact with glass hardware, the rapid formation of a fluffy gelatinous white precipitate is seen. From an X-ray diffraction analysis of the precipitate from operating fuel-cells, it was determined that the principal component was Si3(P04)4, although metallographic and SEM/EDS analyses support the presence of the other silico-phosphate complexes in varying amounts. 

Porcelain dental cements were developed by Steenbock [6] who produced silico-phosphate dental material using 50 wt% concentrated phosphoric acid solution and an aluminosilicate glass. Wilson et al. [7] showed that various brands of commercial cements consist of powdered alumina-lime-silica glass mixed with phosphoric acid, which form a hard and translucent product. The phosphoric acid used in these cements is partially neutralized by aluminum oxide. 

Dental Ceramics, dental porcelain (q.v.) has been supplemented by other BIOCERAMICS, in particular apatites and alumina, for general maxillofacial restorative work, using crowns and implants. Metallising, metal-ceramic bonding and colour matching are important in dental ceramic work. BS 3365 specifies dental silicate and silico-phosphate cements BS 6039 glass-ionomer cements. 

Sharma, K., Dixit, A., Singh, A., Jagannath, S., Bhattacharya, S., Prajapat, C. L., Sharma, P. K., Yusuf, S. M., Tyagi, A. K. Kothiyal, G. P. (2009). Preparation and studies on surface modifications of calcium-silico-phosphate ferrimagnetic glass-ceramics in simulated body fluid. Materials Science and Engineering, 29(7), 2226-33. 

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