Grant: Research Tools and Instruments - Category 1 (<$150,000)

Size Exclusion Chromatography (SEC), also known as Gel Permeation Chromatography (GPC), is a standard chromatographic analysis technique providing detailed information on the size and uniformity of the molecules in a polymer sample (e.g. molecular weight distribution, radius of gyration, hydrodynamic radius, and chemical functionality). The synthesis and the chemical modification of polymers, carried out routinely in the co-applicants' laboratories, both require monitoring by SEC analysis to confirm the success of the reactions and the absence of side (unwanted) reactions. The equipment currently available for that purpose is a fully manual Waters system that is over 20 years old, has neither temperature control nor automated sample injection capabilities, and runs with rudimentary homemade software. In order to remain competitive in research at the international level, it is imperative that the existing equipment be replaced with a state of the art SEC system including suitable detectors. The research programs benefiting from the requested equipment are concerned with (a) the synthesis and the characterization of well-defined branched (dendritic) polymers and (b) the investigation of polymer chain dynamics (mobility) by fluorescence spectroscopy. The differential refractometer, light scattering, viscometer, and UV-visible absorbance detectors selected for the instrument will provide complementary information on branched and linear polymer samples investigated in both laboratories. This information is of fundamental importance in interpreting detailed physical characterization data generated to correlate the structure and composition of the polymers with the properties observed. The requested SEC equipment will also provide training in that modern polymer analysis technique for undergraduate students, graduate students, and post-doctoral fellows.