Influence of Polystyrene (PS) solution concentration on the formation of nanobubbles

Drag reduction of liquid flows on solid/liquid interface has become an important issue with the development of microfluidics systems. Theoretical and experimental studies have shown that at the solid-liquid interface the presence of nanobubbles is believed to be responsible for boundary slip, and the size, quantity and distribution of nanobubbles on hydrophobic surface will influence the slip length. In this paper, surface nanobubbles formed on Polystyrene (PS) films were imaged by atomic force microscope (AFM), and the influences of PS solution concentration adopted when spin-coating on nanobubbles were investigated.