(747a) Experimental Techniques for Vapor-Liquid Equilibrium

In this presentation we will review experimental techniques that have been used for measuring vapor-liquid equilibrium. These will include “synthetic methods”, that do not require analysis of the composition of the phases, as well as “analytical methods”, that require either sampling or non-invasive (e.g. spectroscopic) ways to determine the phase compositions. The range of temperatures and pressures that can be accessed by each technique, and ways to expand these ranges, will be discussed. Methods that are particularly well suited for mixtures with large disparities in vapor pressures (e.g., gas solubilities in polymers or ionic liquids) will be identified. Special attention will be paid to the total mass needed for each technique and experimental uncertainties, as well as the dependence of uncertainty on sample size. We will discuss methods to mitigate the challenges associated with highly viscous materials, as well as those where visual determination of phase coexistence is not possible.