Dispersion and Rheology of Aqueous Zirconium Diboride Nanosuspensions

Abstract

The dispersion and rheology of aqueous ZrB 2 nanosuspensions were investigated by zeta potential measurements, particle size measurements, sedimentation tests, and rheology measurements, with poly (acrylic acid) (PAA) as dispersant. Results showed that the dispersion and rheology of nanosized ZrB 2 suspensions in aqueous media were dependent on pH value, PAA concentration, solid loading, and ball milling time. Concentrated (up to 30 vol% solid loading) and well-stabilized aqueous ZrB 2 nanosuspension with low viscosity (0.485 Pa s at 60/s) was prepared at pH 10, with 1.0 wt% PAA. *

Dispersion behavior of HfC‐based nanopowders in ethanol

“…In addition, the overfull PEI caused the increase in the thickness of ions in electrolyte solution. The higher concentration of ions induced a decrease in the thickness of the double‐charge layer, thus resulting in a decrease in the zeta potential on the surface of particle . These were harmful to the dispersion and stability of the suspension.…”

Influence of surface oxide layer of SiC powder on the rheological properties of its slurry

“…When washing with hydrogen fluoride, the oxygen content decreased to 0.32 at.% showing the SiO 2 layer on the SiC surface was effectively removed. 18,19 It can be seen from Figure 2 SEM pictures that after 2.0% HCl washing (Figure 2A), 20% HF etching ( Figure 2B), and 750°C calcination treatment ( Figure 2C), the particle size and morphology of SiC powder did not change greatly, and all of them showed irregular sheet or block structure. The absorption peaks at 940 cm −1 and 824 cm −1 are the characteristic vibration peak of Si-C bond, and the absorption peak at 1050 cm −1 is attributed to Si-O-Si bond, which indicate the partial oxidation of SiC to SiO 2 .…”

“…After further calcination treatment, the absorption peak of SiC powder changed greatly, and the surface oxidation formed a new SiO 2 layer, which made the characteristic peak of SiO 2 (1050 cm −1 ) enhance obviously (Figure 1c). 18,19 It can be seen from Figure 2 SEM pictures that after 2.0% HCl washing (Figure 2A), 20% HF etching ( Figure 2B), and 750°C calcination treatment ( Figure 2C), the particle size and morphology of SiC powder did not change greatly, and all of them showed irregular sheet or block structure. Relatively, after HF etching the particle size is generally smaller.…”