Fabrication of photosensitive glass with nano-sized metallic gold colloids and study on its color transfer mechanism

Abstract

Nano-sized gold colloids were formed in silicate glass by pyro-metallurgy to make a highly photosensitive glass. Colloid size was controlled by X-ray irradiation and thermal treatment to study the color transfer mechanism of the photosensitive glass. Glass beads for the preparation of the photosensitive glass contained gold cyanide as the colloid former, antimony trioxide as the sensitizer and cerium oxide as the thermal reducer. Transmission electron microscopy (TEM) showed the uniform distribution of the nano-sized metallic colloids in the photosensitive glass. The color of the photosensitive glass with the nano-sized metallic colloids changed with annealing temperature from pink at 400°C to red at 500°C to deep red at 600°C and to blue at 700°C. The size of the gold colloids significantly influenced the color transfer behavior: 10.4 nm size yielded pink; 15 nm, deep red; 22.0 nm, violet; and 32.0 nm, blue. The color transfer mechanism was related to the reduction of the metallic ions, the growth of the metallic particle, and crystallization. They included the productions of sufficient electrons for the reduction of the gold ions by X-ray and the agglomeration of the gold atoms, crystallization and size-growth by heat treatment.