Finely perforated glass substrate with silver concentration gradient

摘要

A glass substrate, with a fine hole, contains silver in atomic, colloidal or ionic form with a concentration gradient in which the silver concentration gradually decreases from (i) the substrate surface down to a preset depth from the hole opening; (ii) a maximum value at one opening of the hole down to a minimum value at another opening of the hole; or (iii) a maximum value at both openings of the hole. Preferably, the glass substrate is a silica glass plate or cylinder which may have several 10-300 mu diameter holes extending in one or two directions, the maximum silver concentration preferably being greater than 0.1 mol%.