DEVELOPMENT OF A DIELECTRIC SPECTROSCOPY PROBE FOR CHARGE AND SIZE ANALYSIS OF INDUSTRIAL COLLOIDS

THIS PROJECT FOCUSES ON DESIGNING A STABLE AND ROBUST MICROSENSOR PROBE FOR DIELECTRIC SPECTROSCOPY THAT IS CAPABLE OF OPERATING OVER A WIDE FREQUENCY RANGE, AND ELIMINATES ALL KNOWN PROBLEMS IN THE MEASUREMENT SYSTEMS USED AT VARIOUS LABORATORIES. TO INTERPRET THE DIELECTRIC SPECTRA, DECONVOLUTION METHODS ARE BEING DEVELOPED TO ESTIMATE THE PARTICLE SIZE DISTRIBUTION FUNCTION AND THE SURFACE CHARGE DENSITY. FINALLY, TESTS ARE BEING CONDUCTED ON WELL-FORMULATED AND WELL-CHARACTERIZED COLLOIDAL SUSPENSIONS TO EVALUATE PERFORMANCE OF THE MICROSENSOR PROBE AND DECONVOLUTION ALGORITHMS. THE INNOVATION RESULTS FROM A COMBINATION OF: (1) EXPERTISE IN DESIGN OF ELECTRICAL SIGNAL PROCESSING FOR COLLOIDAL INSTRUMENTS INVOLVING MICRO-ELECTROPHORESIS AND VIBRATION POTENTIAL TO OBTAIN PARTICLE ZETA POTENTIAL; AND (2) EXPERIENCE IN DECONVOLUTION OF ULTRASOUND AND FOURIER TRANSFORM INFRARED SPECTRA TO OBTAIN PARTICLE SIZE DISTRIBUTIONS. PHASE I OF THE PROJECT ADDRESSES THE ISSUES OF DESIGNING A SPECIALIZED MICROSENSOR PROBE FOR DIELECTRIC SPECTROSCOPY AND DEVELOPING DECONVOLUTION OF DIELECTRIC SPECTRA THROUGH INVERSION FREDHOLM-INTEGRALS IN COMPLEX NUMBER DOMAIN. THIS SENSOR IS EXPECTED TO MEET THE NEEDS OF INDUSTRY IN THE FIELD OF SIZE AND CHARGE CHARACTERIZATION OF COLLOIDAL SYSTEMS WITH LOW DENSITY CONTRAST, WHERE THE ULTRASOUND-BASED SENSORS CURRENTLY AVAILABLE OR UNDER DEVELOPMENT ARE FOUND TO BE OF LIMITED USE.