Interfacial nanobubbles on different hydrophobic surfaces and their effect on the interaction of inter-particles

• Interfacial nanobubbles (INBs) were systematically researched on different hydrophobic surfaces by TIRF and AFM. • The formation of INBs is closely related to the hydrophobicity of substrates, and more large INBs form on strong hydrophobic surface. • The hydrophobic interaction distance and force between hydrophobic surfaces is positive related to the dimension of INBs. • INBs should be responsible for the hydrophobic interaction of inter-particles is proposed. To develop interfacial nanobubbles (INBs) into application fields, it is of great significance to understand the properties of INBs and their effect on the interaction of inter-particles. In this paper, the morphology of INBs on different hydrophobic surfaces was researched by total internal reflection fluorescence microscopy (TIRF) and atomic force microscope (AFM). A hydrophobic AFM colloid cantilever was used to measure the interaction of inter-particles in the absence and presence of INBs. The results confirm that the formation of INBs is closely related to the hydrophobicity of substrates, more large INBs form on the strong hydrophobic surface (SS). Furthermore, the magnitude and range of the hydrophobic interaction force are positive related to the dimension of INBs. Besides, multiple approaches of hydrophobic colloid to SS, the hydrophobic interaction is further enhanced due to the merging and cavitation of INBs. Therefore, the results presented here provide the relationship between INBs formation and surface hydrophobicity, as well as the effect of INBs on particles interaction. The formation of INBs should be responsible for the hydrophobic interaction of inter-particles, which is a basic insight into the hydrophobic interaction between particles.