Showing papers by "Patrick S. Nicholson published in 1999"
TL;DR: In this paper, the surface chemistry and interparticle forces were manipulated by controlling the ionic strength of the suspensions without dispersants, and the effects of the chemical nature of the solvents and the concentration of dispersed particles on the suspension rheology were evaluated.
Abstract: Alumina particles were dispersed in ethanol (EtOH) and dimethyl sulfoxide (DMSO). The surface chemistry and interparticle forces were manipulated by controlling the ionic strength of the suspensions without dispersants. The effects of the chemical nature of the solvents and the concentration of dispersed particles on the suspension rheology were evaluated. It was observed that the viscosity of suspensions decreased with increasing salt concentration. Solvent type also had a marked influence on the suspension rheology. Interparticle interactions were calculated and used to describe the rheological behavior.
27 citations
TL;DR: In this paper, the ionicity of binary oxides is presented as a function of the inverse of cation radius, and the molar refractivity of silicates calculated on the basis of the ionivities of component oxides agrees with measured values.
24 citations
TL;DR: In this paper, a diffusion model was proposed to fit the measured chemical-transformation rates of the Bi(Pb)CaCuSrO 80-K phase to 110-k phase.
Abstract: A diffusion model is proposed to fit the measured chemical-transformation rates of the Bi(Pb)CaCuSrO 80-K phase to 110-K phase. Diffusion coefficients and activation energies in PO2 = 0.08 and 0.21 atm are reported. The low diffusion rates and high activation energies suggest cation diffusion controls the transformation.
12 citations
TL;DR: The phase formation in the system Na 2 O-Ga 2 O 3 has been studied at 800-1350°C via solid-state reaction between gallium oxide and sodium carbonate as mentioned in this paper.
4 citations
TL;DR: In this article, structural modifications involved in hydration and dehydration are discussed, and two hydrates form and their appearance is kinetically controlled by twofold diffusion, and the dissolution of Na2O leads to hydronium-β-gallate.
2 citations