Lead Silicate Glasses

Hydrofluoric acid must not be stored in glass or silicate ceramic containers. Stainless steel or PTFE are satisfactory for storage and handling. Nonferrous materials such as carbon, bronze, Monel or lead may be used for weaker acids. 

Glass fibers of various compositions Frits of various compositions Lead silicates Borate compounds... 

Barium oxide is introduced into glass as BaCOs, less frequently as BaSO, or in the case of optical glasses as Ba(N03)2- The most frequently used lead taw materia] is Pb304 (minium, red lead) or PbO, and possibly also the less volatile lead silicate. Small amounts of AI2O3 enter glass as subsidiary components of sand and limestone. If a higher alumina content is required, use is made of aluminium oxide or hydroxide, feldspar, kaolin, phonolite, etc. 

A series of lead silicate glasses and their crystalline equivalents has revealed a linear relationship between the number of Pb atoms in the second coordination sphere of the structural Si tetrahedra (p) and the isotropic Si chemical shift (Bessada et al. 1994), defined by ... 

Lead silicate glasses having different mole ratios of Si02 to PbO and containing different amounts of alkali/alkaline earth metal oxides were prepared by conventional melt-quench method. The different structural units of Si present in these glasses were identified by Si MAS NMR. ... 

Fig. 2 Viscosity versus temperature characteristics for various glass compositions [7]. 1, Fused silica 2, 96% silica 3, soda lime (plate glass) 4, lead silicate (electrical) 5, high-lead 6, borosilicate (low expansion) 10. aluminosilicate...

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