Separation of Complex Materials by Composition Using Thermal Field-Flow Fractionation

This project is a Research in Undergraduate Institutions (RUI) activity directed by Dr. Martin E. Schimpf of the Chemistry Department at Boise State University, and supported by the Analytical and Surface Chemistry Program in the Division of Chemistry. The focus of the research is on Thermal Field-Flow Fractionation (ThFFF). This separation technique is based on thermal diffusion and the separation process is known to depend on both the chemical composition and the molecular weight or size of the compounds under investigation. Work by undergraduate students will be done to develop a fundamental understanding of thermal diffusion, particularly in terms of the separation of macromolecules and particulate matter. The effect of properties of the sample material and the carrier solvent will be studied to reveal their impact on retention. Factors governing thermophoretic motion of polymers such as the effect of chain branching will be investigated. The knowledge gained from the fundamental work will be applied to practical separation problems involving copolymers. A combination of ThFFF with measurements of viscosity will be used to obtain the average molecular weight and composition of block copolymers. Two-dimensional separations using ThFFF and size exclusion chromatography will be investigated. The ability to separate the components of complex mixtures of compounds is vital to the successful solution of a number of major problems in chemical analysis such as the identity and concentration of environmental pollutants, and the composition of drug formulations. This project, to be carried out by undergraduate students, will investigate the fundamental basis and applications of a separation method known as Thermal Field-Flow Fractionation (ThFFF). A major factor for the interest in this approach is that the method is potentially applicable to the separation of polymer materials in solution and solid particles of matter.