Effect of nanobubbles on the dispersion stability of nanoparticles in liquid phase systems

Understanding how nanobubbles influence the dispersion stability of nanoparticles is a key challenge worth exploring in industrial applications. This study employs coarse-grained molecular dynamics (CG-MD) simulations to investigate how nanobubbles impact the dispersion stability of solid nanoparticles in different dispersant systems (SMA/HSMA). The results show that the hydrophobic group of the dispersant dominates the competitive adsorption of the whole molecule on the hydrophobic surfaces of nanoparticles and nanobubbles. Electrically neutral SMA forms compact micelles on the surface of nanobubbles due to strong hydrophobicity, thereby weakening its stabilizing effect on nanoparticles and reducing the stability of the dispersion system. HSMA does not aggregate excessively on the surface of nanobubbles due to the electrostatic repulsion of charged groups, thus maintaining the dispersion stability of nanoparticles. The above results clarify that the effect of nanobubbles on the dispersion stability of nanoparticles is regulated by the charge of dispersants, revealing the key role of electrostatic repulsion in maintaining the stability of nanoparticles in the system containing nanobubbles, and providing a new molecular-level basis for understanding the effect of nanobubbles on the dispersion stability of nanoparticles.