Synopsis
Flocculation and sedimentation of fine particles are investigated here with emphasis on the role of conformation of adsorbed polymers on flocculation. theoretical modelling of aggregation and sedimentation processes. and structural characterization of sedimentation and floccs.
Polymer adsorption and. more importantly, the configuration of adsorbed polymer is considered critical in flocculation/dispersion processes. We have developed a fluorescence spectroscopic technique to investigate the conformational aspects of polymer adsorption. We have also successfully applied this technique to monitor coiled/stretched transformation of adsorbed polymers and to correlate the conformational information with the flocculation performance in the same system. Charncterization of floccs is a major hurdle in flocculation studies and in this regard we have initiated the characterization of sedimentation processes and flocc structure by a CAT scan.
A Monte Carlo model has been developed and applied successfully to simulate sedimentation of fine particles by considering sedimentation as the result of competition between gravitation and the Brownian motion. In computer simulation of aggregation. the diffusion-limited aggregation model has been modified to generate sparse floccs as well as dense floccs by varying the step size of random walks.