Author:
Ryan Vivian,Smolinsky Gerald
Abstract
ABSTRACTThis paper describes an analysis of the physical properties of the sol using several complementary light scattering techniques. Polymerization and aggregation kinetics were followed through time-dependent changes in the size, shape, and density of the sol particles. The sot growth rate was controlled by choice of solvent and silicon concentration. Changes in viscosity and pH were small during the reaction period. Three different particle-growth regimes exist in which either the particle density increased, decreased, or remained the same. The addition of boron, hydrofluoric acid, or water accelerated the reaction. The sol experimental data correlate with the density and wet-etching rate of the cured films. After curing, high-density films were obtained from sols with three common characteristics: an average particle diameter >450 Å, a relatively high polydispersity, and a low particle density. These criteria were generally satisfied by solutions one to two days old.
Publisher
Springer Science and Business Media LLC