Chapter 7: Nanobubbles, Dissolved Gas, Boundary Layers and Related Mysterious Effects in Colloid Stability

My scientific and personal relationship with Brian Vincent commenced in 1978 when I came to Bristol to work on static and dynamic light scattering studies of microemulsions. I worked with Ron Ottewill at Bristol, Peter Pusey at the RSRE in Malvern and Tharwat Tadros at ICI in Jealott's Hill. During this period of six months at Bristol, I got to know Brian and very much appreciated his studies on colloid stability, steric stabilisation, the nature of adsorbed layers and the like. Over the period since 1978, our scientific interactions and friendship have blossomed tremendously. We have exchanged PhD students and some excellent postdoctoral fellows. My research interests are aimed at answering questions about why bubbles and particles interact, the static and dynamic aspects of wetting and colloid stability. In this chapter, I review some of our most recent work on the way in which dissolved gas and surface nanobubbles influence colloid stability. Along the way I illustrate how these “boundary layer” bubbles and adsorbed gas layers play an important role, drawing on many of the concepts that Brian has developed and used over the many important years of his scientific research.^1,2