Glass, calcium phosphate

Ceramics and Glasses Calcium phosphate Bone regeneration... 

Human osteoblast-like MG63 cells were cultured on the macroporous chitosan scaffolds reinforced with hydroxyapatite or calcium phosphate invert glass were fabricated using a thermally induced phase separation technique. 

Chitosan scaffolds were reinforced with beta-tricalciiun phosphate and calcium phosphate invert glass [177]. Along the same line, composites of Loligo beta-chitin with octacalcium phosphate or hydroxyapatite were prepared by precipitation of the mineral into a chitin scaffold by means of a double diffusion system. The octacalciiun phosphate crystals with the usual form of 001 blades grew inside chitin layers preferentially oriented with the 100 faces parallel to the surface of the squid pen and were more stable to hy-... 

Izquierdo-Barba, I., Salinas, A.J. and Vallet-Regi, M. (1999) In vitro calcium phosphate layer formation on sol-gel glasses of the CaO-Si02 system. Journal of Biomedical Materials Research, 47, 243-250. 

From a theoretical point of view, the gel layer is a barrier that reduces further hydrolysis of the silicate network, and is supposed to be more stable than the glass matrix, thus reducing the overall rate of corrosion. However, gel exfoliation may momentarily re-activate corrosion, at least locally. No clear trend was observed for the presence of the crystalline secondary phases identified at the surface of the corroded HT samples. The most abundant minerals are aluminosilicates, calcium phosphates, Fe- and Mg-rich minerals, and zeolites their role in the scavenging or release of metals remains ambiguous, although many mineral phases identified bear traces of metals. 

PIA-Calcium Phosphate-Based Glass Fibers Artificial Tendon and Ligament... 

A. Baudrimont and J. Pelouze (1833) fused the sodium sulphate with galena or zinc blende and formed the alkali plumbate or zincate, and J. B. M. P. Closson boiled a soln. of sodium sulphate with milk of lime and lead oxide. The plumbate can be decomposed by sulphide, carbon dioxide, or by electrolysis. The St. Gobain Co. patented a process in which sand, coal, and sodium sulphate are heated together water-glass is formed and a soln. or suspension of that salt in water is decomposed by carbon dioxide or by milk of lime. J. Simpson (1890), J. C. Ody (1892), N. Basset and W. von Baranofi (1894) decomposed a soln. of sodium sulphate by calcium phosphate in dil. acid. The soluble sodium phosphate which is formed... 

The most important bio-active materials are calcium phosphate, hydroxyapatite and glass ceramics. 

A number of spectacular applications in structural studies of glasses were reported employing the INADEQUATE experiment.174 175 The basic sequence and different modifications were discussed in Section 2.2.2. Smith and coworkers176 used 31P refocused INADEQUATE MAS NMR experiment for searching the length of phosphate chain and quantification of crystalline phases in ternary sodium calcium phosphate ceramic of composition (CaO)0.4(Na20)0.i(P205)o.5. 

Less intensive opaline opacity can be brought about by the introduction of phosphates (3 — 8% P2O5 in glass) in the presence of CaO an emulsion of calcium phosphate is precipitated in the glass and then partially crystallized. The systems P2O5 —RO (where RO = BaO, SrO, CaO, MgO, ZnO, CdO, PbO) are glass-forming up to 56—65 mole % RO. The opacity of phosphate opals is promoted by the addition of fluorides. 

If the calcium phosphate fibers grown from ultraphosphate melts are slurried with a solution of sodium ethylene diamine tartaric acid the calcium crystals can be converted to a sodium phosphate glass that dissolves very slowly yielding very long chains. 

I<. (1994) Preparation of apatite thin films through rf-sputtering from calcium phosphate glasses. J. Am. Ceram. Soc., 77 (9), 2401-2407. 

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