Sodium leaching from borosilicate glass

The slow rate of dissolution of, or leaching from, durable glasses has led to proposals for the vitrification of nuclear waste. Glasses based on the sodium borosilicate system appear to be favoured because of their ability to dissolve the waste, combined with good chemical durability. Intensive development has taken place over recent ycars and a regular journal is devoted to this topic . 

Patents [102, 103] describe the preparation of open tubular columns with an inside thickness-fixed porous layer by etching. First, the authors prepared a capillary column from a two-layer workpiece composed of two concentric tubes, one of them (external) being made of sodium borosilicate glass. To obtain an adsorption layer of defined thickness, the inner layer of the two-layer capillary was entirely leached. The method relies on porous glasses as the adsorbents. Porous glasses have been successfully used in gas capillary (see, for example, [104]). 

Figure 6.8 Na (by RBS) and H (by ERD) depth profiles of the surfaces of a sodium borosilicate glass leached in a pH 8 aqueous solution at 70 °C for various times. (From Reference 25.)...

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