The binary nucleation of n-octane and iso-octane

Abstract

This chapter presents preliminary results from the measurements of the nucleation of n-octane and isooctane. It discusses the difficulties with these measurements. It characterizes the data as showing the highest supersaturation, which one can achieve for a specific number of drops. The chapter measures the nucleation of pure n-octane and isooctane and one binary mixture with an expansion cloud chamber. These isomers were selected as a “nearly ideal” system with the expectation that information about the surface of a nucleation embryo could be extracted from the data. Conventional binary nucleation theory considers the nucleation embryo as a surface and a bulk mixture. For this model, one can ask, the surface tension that should be used to describe the surface of an embryo of only a few 10's of molecules. The experimental investigation of the binary nucleation of octane isomers is an attempt to isolate, as a single variable, the effects on nucleation of the changing of the surface of the embryo.