Silicon from borosilicate glass

In particular, the model results in a system of coupled, nonlinear ordinary and partial differential equations which have been fully implemented in a computer code, named LIX, to predict elemental releases of silicon and sodium from borosilicate glass. 

Table 6 shows the major metal oxides and the iron oxide impurity levels of typical borosilicate Type I glass. Up to 0.05% by weight (500 ppm) iron oxide as Fe O may exist in the borosilicate Type I glass. Thus, the increase in iron levels with time likely reflects a slow leaching of iron from the glass vial. Consistent with this explanation is that similar increases in silicon, aluminum, calcium, and barium levels are also observed in older product lots as shown in Table 6. Note that these nontransition metal ions are not known to participate in the type of reactions depicted in Figure 6. Furthermore, it is not clear if the expected increase in iron leaching from amber vials (Table 6) will be readily compensated for by the reduced light transmission at the causative wavelengths offered by utilizing the amber vial as the primary package.

Boron s chemistry is so different from that of the other elements in this group that it deserves separate discussion. Chemically, boron is a nonmetal in its tendency to form covalent bonds, it shares more similarities with carbon and silicon than with aluminum and the other Group 13 elements. Like carbon, boron forms many hydrides like silicon, it forms oxygen-containing minerals with complex structures (borates). Compounds of boron have been used since ancient times in the preparation of glazes and borosilicate glasses, but the element itself has proven extremely difficult to purify. The pure element has a wide diversity of allotropes (different forms of the pure element), many of which are based on the icosahedral Bj2 unit. 

Microfluidic devices have been fabricated from a wide range of materials, such as silicon, fused silica, borosilicate glass, elastomers (poly(dimethylsiloxane)... 

Figure 17 The depth of borosilicate glass surface removed as a finietion of the applied electric field using the 30 wt% 1 Ojim-in-diam starch particle mixed with 4 wt% 2 pm-in-diam diamond particle dispersed in the silicone oil, and the diamond/silicone oil suspension, respectively The diamond/silicone oil suspension shows a very weak HR effect. Reproduced with permission from W.B, Kim, S.J. Lee, Y.J. Kim, E.S. Lee, Int, J. Machine Tools Manufacture, 43 (2003) 81.

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