Understanding the entrainment behaviour of gangue minerals in the presence of nanobubbles is necessary for the application of nanobubble technology in froth flotation. In this study, the entrainment of kaolinite particles in flotation with nanobubble water produced by decompression, and tap water, was investigated. Compared to tap water, nanobubble water enhanced the entrainment of kaolinite particles in flotation. Rheology measurements together with settling tests were further employed to examine the effect of nanobubbles on clay particle association and its correlation with the entrainment of kaolinite particles. The presence of nanobubbles appears to induce and stabilise E-E contacts of kaolinite platelets, resulting in the formation of porous three-dimensional structures. These open structures with abundant interstitial voids had a low settling velocity and therefore were more readily recovered by entrainment. (C) 2019 Elsevier B.V. All rights reserved.