In-situ observation on the capillary corrosion of the water-mediated glass microspheres

• Glass and gold microspheres immersed in water and dried were examined in E-SEM.
• Bridging materials has been observed between glass microspheres.
• No bridging materials have been observed between gold microspheres.
• In-situ E-SEM observation showed the removal process of bridging materials.
• Gelatinous behaviors of bridging materials suggest the corrosion products of glass.

Glass microspheres were treated with purified water to observe the formation of capillary bridges between the contacting microspheres using high resolution environmental scanning electron microscopy. The observed bridges between glass microspheres were found to shrink under exposure to the electron beam showing evidence of the gelatinous nature while identical experiments with gold spheres did not show any connecting bridges. It was found that the bridges between glass microspheres consist of siliceous corrosion products with high Na concentration which alter interfacial behaviors of contacting glass colloids.