Effect of phase separation on precipitation characteristics of CuCl quantum dots in the borosilicate glass system

Abstract

Abstract Effects of phase separation on the precipitation of CuCl particles in the sodium-borosilicate glass system have been investigated using acid elution measurement, UV/VIS absorption spectroscopy, and scanning and transmission electron microscopy. Compositions of 7.5Na2O40B2O352.5SiO2 and 22.5Na2O340B2O337.5SiO2 (wt%) were chosen as matrix glasses based on their phase separability and the relationship between the phase separation of the glass matrix and the precipitation of CuCl particles was studied. The CuCl precipitation occurred only in the phase-separable glass matrix and the radius of the CuCl nanocrystals increased with heat treatment time. The CuCl crystals were precipitated both in the boron-rich phase and in the silica-rich phase. Larger CuCl particles, with an average size of ∼ 3.3 nm, than those in the silica-rich phase, which averaged ∼ 1.7 nm, were observed to precipitate in the boron-rich phase. The observed CuCl particle size difference and the non-uniform distribution of the particles are attributed to the fast growth of the CuCl particles due to the lower viscosity of the boron-rich phase compared to that in the silica-rich phase.