How to expose hydroxyl groups in glass

The following cleaning techniques are used to remove organic molecules adsorbed on the glass surface. The purpose of these methods is to expose hydroxyl and siloxane bonds in glass molecules.

Two better methods for cleaning glass substrates are UV/ ozone cleaning and pyrolysis, which are environmentally friendly and non-toxic. A UV/ ozone cleaning method using a low-pressure mercury lamp in an oxygen-containing atmosphere is described in J.Vac.Sci.Technol.A 3, 1027, (1985) by Vig et al., the contents of which are incorporated into the present invention by reference. The device suitable for this cleaning method is to install BHK's low-pressure mercury grid lamp (88-9 102-20) in a steel shell filled with air. Placing the surface to be cleaned about 2 cm away from the lamp can activate the surface for about 30 minutes, and then clean the surface.

The second technique is pyrolysis, in which the surface is slowly heated to about 500℃, kept at this temperature for about 4 hours, and then slowly cooled. When heating and cooling, the temperature usually rises and falls for about 5 hours. Other cleaning techniques include laser ablation and letting the flame pass through the surface.