Engineering Research Equipment Grant: Spectrofluorometer forIn-Situ Probing of Solid-Liquid Interface and Adsorption Phenomena

For a deeper understanding of the adsorption process in general and of the microstructure of the adsorbed phase in particular, this grant funds purchase of a spectrofluorometer capable of steady-state and time-resolved fluorescence measurements. The equipment is provided with double monochromators at the excitation and emission ends for optimum performance and has the facility to record corrected luminescence decay-time measurements. It was thyratron grated, flash lamp triggered nanosecond pulse to excite the luminescent samples. It can also measure time-resolved spectra. Surfactants and polymers adsorbed on a solid surface from solution modify surface properties drastically. Such phenomena have far reaching effects on the industrially and technologically important processes of flotation, flocculation, fine particle separation, oil recovery, and processing of electronic and ceramic green bodies. Earlier workers have focused on measurements such as adsorption density, zeta potentials, and contact angels. Recent efforts using fluorescence spectroscopy have demonstrated the potential of luminescence techniques to elucidate the structure and dynamics of evolution of the adsorbed layer in great detail. This award will significantly expand such work.