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Potentials of the electrooptical method for studying fast coagulation have been considered. Results of studying particle aggregation in aqueous diamond and graphite colloids containing AlCl3 as an electrolyte have been represented. A comparative analysis has been performed for the aggregation rates of diamond and graphite particles at low values of their electrokinetic potentials. It has been found that, at a low electrokinetic potential, a change in its value by a few millivolts alters the stability of diamond and graphite colloids by several times. The investigations have shown that, at the isoelectric point, the formation rate of paired aggregates is five times higher for graphite particles than that for diamond particles at close particle number concentrations. This indicates significant differences in the surface structural components hindering aggregation of graphite and diamond particles. The electrooptical method has been employed to measure the relaxation dependences of electrooptical effects corresponding to different time periods elapsed after the onset of colloid coagulation. These dependences have been used to determine the size distributions functions for particles and their aggregates and to analyze variations in these functions in the course of coagulation. It has been shown that the used method is efficient and applicable for studying the kinetics of fast coagulation. [ABSTRACT FROM AUTHOR]

Electro-optical techniques currently used to study disperse systems allow to determine different geometrical and electrical particle parameters in these systems. To reliably determine some of these parameters a long electric impulse or series of impulses has to be applied, which can alter some of the systems under study. To address this issue and allow to study disperse systems that cannot undergo lengthy application of electric field in our previous work we have proposed a technique to apply short pulses of electric field to the system under study which still allows determining particle parameters just like regular electro-optical techniques. In this article we further develop this technique by generalization of equations to the case of arbitrary field shape and particle orientation mechanism. The obtained experimental data for L. Monocytogenes verifies the developed equations for big particles. [ABSTRACT FROM AUTHOR]