Current Research

Vapor-liquid equilibria of alcohol-hydrocarbon mixtures.  In this study, ternary systems which contain two associating (hydrogen bonding) species and a single nonassociating species are examined. The project consists of obtaining new experimental data, developing new data reduction models and developing new solution models that account both for self and cross association of hydrogen bonding species using the infinite equilibria model. More recently, I have begun collaborating with Dr. W.E. Acree Jr., at the University of North Texas, in testing solution models for their ability to represent both VLE and solubility data. Also, I am co-advising (with Dr. Venkat Bhethanabotla, USF) a student who is studying hydrogen bonding in alcohols via Monte Carlo simulation. Of particular interest is the study (via both simulation and experiment) of the effect of isomer structure on alcohol association.

Vapor-liquid equilibria in other associated systems. Here, systems in which species associate or form complexes with other species are examined. For example, studies of the acetone-chloroform-toluene system and the chloroform-acetone-methyl ethyl ketone system have been completed. The binary systems have been represented by a monomer-dimer association model in which structures reported in the literature are incorporated. Prediction of the ternary data is excellent and requires no additional information beyond that obtained from the binary systems.  Currently, I am developing a solution model that may be applied to systems containing any number of associating species, each having an arbitrary number of bonding sites.

Vapor-liquid equilibria of systems comprised of electrolytes in mixed solvents. The systems under examination in this study are comprised of a single nonvolatile electrolyte in a mixed solvent. The first part of the project involved using literature data to show the feasibility of obtaining future data via the total pressure method. The second part of the project involved obtaining vapor-liquid equilibrium data for ternary mixtures and developing solution models for their prediction and representation.

Phase equilibria of polymer-solvent mixtures. An apparatus which uses a quartz crystal to measure sorption of solvent vapors in a polymer film coated on the crystal has been built. The apparatus is used to measure solvent activities in the solvent-polymer mixtures in the range of approximately 10 to 30 weight percent of solvent. Tests have been completed for binary mixtures of polystyrene with benzene, toluene or chloroform. Agreement with literature data is excellent and new studies with other polymers and solvents will be made. This project is also in collaboration with V. R. Bhethanabotla, an Associate Professor of Chemical Engineering at USF.