Synergistic Predrying and Surfactant Strategy for Enhanced Dispersion Stability of Magnesium Hydroxide Particles in Nonpolar Solvents
The dispersion of magnesium hydroxide (Mg(OH)2) particles in kerosene is crucial for the pyrolytic treatment of radioactive organic liquid wastes yet is severely hindered by water preadsorbed on particle surfaces from ambient air. This work investigated the effect of preadsorbed water on the dispersion stability and rheological properties of Mg(OH)2 particles in kerosene. We correlated preadsorbed water content with the suspension’s microstructure and rheology and revealed that powerful capillary attractions between particles induced by preadsorbed water can negate the stabilizing action of surfactants. Mg(OH)2 particles with 8.1% preadsorbed water (mostly in the state of capillary water) formed large, robust aggregates in kerosene, resulting in a higher storage modulus (92 kPa) of the concentrated suspension. Even with the addition of a surfactant polyoxyethylene alkyl ether carboxylic acid (CE10Ac), the storage modulus remained high at 1.8 kPa due to the dominant capillary forces. To overcome this challenge, we proposed a synergistic approach combining particle predrying with surfactant modification. Predrying particles can eliminate the capillary forces by removing the capillary water and enable the effective adsorption of CE10Ac molecules onto individual particle surfaces. This strategy promotes strong steric and solvation stabilization, yielding stable, low-viscosity (<40 mPa·s) suspensions. These findings offer a practical route for preparing advanced materials for radioactive waste treatment.
危险品化学品经营许可证（带存储）