Amphiphobic carbon nanotubes as macroemulsion surfactants

Single-walled carbon nanotubes (SWNTs) are insoluble in either water or oil. When mixtures of SWNTs, water, and toluene are sheared vigorously, a macroscopic emulsion of water droplets forms in toluene, with the SWNTs residing at the interface between the immiscible fluids, acting as a natural surfactant or interphase material. The average droplet dimension decreases as the SWNT/water mass ratio increases, implying a coarsening-and-pinning mechanism. The concept of emulsification via amphiphobicity will find applications in processing nanotubes, compatibilizing immiscible fluids, and creating new macroscopic emulsion. materials with unique interfacial and structural properties.