Glass, inorganic phosphate glasses

J.U. Otaigbe and G.H. Beall, Inorganic Phosphate Glasses as Polymers, Coming Research, p. 31, 1997. 

Inorganics Oxides (glass, MgO, Si02, A1203) Hydroxides (Al(OH)3) Salts (CaC03, BaS04, CaS04, phosphates) Silicates (talc, mica, kaolin, woolastonite) Metals (boron, steel fibers)... 

A similar method is used for the determination of inorganic phosphates in urine. 1 to 5 c.e. of the urine, containing about 0-5 milligram of phosphorus, are diluted and treated with a solution of ammonium molybdate in 15 per cent, sulphuric acid (5 c.c.), 1 c.c. of 1 per cent, hydroquinone solution and 1 c.c. of 20 per cent, sodium sulphite solution. The blue colour is compared in Nessler glasses with that developed by the same solutions when mixed with a standard phosphate solution of which 5 c.c. contain 0-5 milligram of phosphorus. 

Collect the filtrate and record its volume. Remove duplicate 0.05, 0.1, 0.2, and 0.5 ml samples of the filtered solution for the inorganic phosphate and 7-min phosphate assays described in steps 5 through 9. Place these duplicate samples in small, labeled glass test tubes. 

In our hands, it is absolutely necessary to thoroughly clean the glass tubes in chromic acid. As the explosive HCIO is used to convert organic into inorganic phosphate, the presence of large amounts of oxidizable organic compounds in the solurion(s) should be avoided as this may cause a burst of flame ... 

Later in this review, examples will be presented where rotor-synchronized H DQ MAS spectra provide both structural and dynamic insight. The method is, however, not restricted to H NMR, for example, 3ip 3ip pjQ MAS spectra of inorganic phosphates and glasses have also been presented.101 105 In addition, Nielsen et al. have presented a 13C-13C DQ MAS experiment,106 using which C—C connectivities of the alkyl backbone can be established, thus, allowing the... 

Spectra and Energy Transfer of Rare Earths in Inorganic Glasses Oscillator strengths (f) of Tn in horate and phosphate glasses f = 4.318 X 10 ... 

The solvents used were (a) HPLC grade methanol and acetonitrile (Fisher Scientific) (b) water, double-distilled and stored in glass. Inorganic salts and acid (ammonium sulfate, potassium phosphate monobasic, potassium phosphate dibasic and phosphoric acid, 85%) were analytical reagent grade (Malllnckrodt Chemical Works). 

Solid inorganic phosphates are fairly stable to UV and x-radiation, but pure colourless sodium metaphosphate glass turns pink. Certain metaphosphate glasses will fluoresce strongly under ultraviolet light if they have been previously irradiated by y-rays. 

When preparing synthetic fibers it is usually preferable to avoid crystals that can undergo phase transitions in the temperature ranges of their intended application. This is one reason why amorphous inorganic phosphate fibers may not function well for an extended period. Attempts to prepare phosphate glass fibers have always met with failure in past years when refractory requirements were desired. Additionally, molecular weights in glasses are relatively small when compared to crystals of a similar composition. Two problems have usually been encountered. 

Inorganic phosphate chemists have normally treated their systems in much the same conventions in drawing structures and placing cations as organic chemists have done. In melts and glasses this is probably justified, but in a solid crystalline state it is well known that placement of cationic functions in structures is an oversimplification. Nevertheless, we shall follow the conventions for convenience, while recognizing that placement of anions and cations is often not a good representation. 

Synonyms Glassy sodium Graham s salt Hexametaphosphate sodium salt Hexa-sodium metaphosphate HMP Metaphosphoric acid, hexasodium salt Phosphate, sodium hexameta- SHMP Sodium phosphate glass Sodium polymetaphosphate Classification Inorganic salt Ionic Nature Anionic Empirical O jPg 6Na Formula (NaPOjjg... 

Dental silicate cement was also variously known in the past as a translucent, porcelain or vitreous cement. The present name is to some extent a misnomer, probably attached to the cement in the mistaken belief that it was a silicate cement, whereas we now know that it is a phosphate-bonded cement. It is formed by mixing an aluminosilicate glass with an aqueous solution of orthophosphoric acid. After preparation the cement paste sets within a few minutes in the mouth. It is, perhaps, the strongest of the purely inorganic cements when prepared by conventional methods, with a compressive strength that can reach 300 MPa after 24 hours (Wilson et al, 1972). 

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