Dispersion of Boron Nitride Powders in Aqueous Suspensions with Cellulose

TL;DR

This study explores how cellulose derivatives can effectively disperse boron nitride powders in water, resulting in stable, high-loading suspensions suitable for advanced ceramic processing.

Contribution

It demonstrates the use of cellulose derivatives as dispersants for boron nitride powders, a novel approach for improving dispersion in aqueous suspensions.

Findings

Cellulose derivatives adsorb onto BN particles, confirmed by isotherm measurements.

Suspensions are highly loaded and stable across pH ranges.

Cellulose enables homogeneous dispersion of BN and additives.

Abstract

The dispersion of nitride and carbide ceramic particles in water is difficult, due to the absence of hydroxyl groups on their surface. Boron nitride is not an exception and despite its numerous applications, no effective dispersant has been identified so far. We demonstrate here the dispersion properties of two cellulose derivatives for hexagonal boron nitride powders, hydroxyl ethyl cellulose and methyl cellulose. The effect of particle sizes and cellulose concentration was investigated. The adsorption of cellulose onto the surface of the BN particles was confirmed by isotherm adsorption. Zeta potential measurements shows a charge screening effect of the cellulose The suspensions obtained were highly loaded and stable versus pH, and thus could lead to homogeneous codispersion of BN particles and sintering additives.