Experimental study of the polydispersity of aqueous colloid of palygorskite and suspensions of Escherichia coli and Pseudomonas fluorescens by an electrooptical method

The results of experimental study on the polydispersity of an aqueous collo id of palygorskite and aqueous suspensions of Escherichia coil (E. coli) an d Pseudomonas fluorescens (Ps. fluorescens) are reported. The study is base d on the use of a new method; i.e., on the investigation of an electrooptic al effect appearing when a weak sinusoidal electric field with sinusoidal a mplitude modulation is applied on the system. This method was developed for studying systems in which only slight particle orientation is possible und er action of an external electric field. Disperse systems with a high condu ctivity, including cell suspensions and other bio-colloids, colloids contai ning small particles, as well as solutions of macromolecules and polyelectr olytes, are among such systems. The experimental setup developed in this wo rk is described. The results obtained are compared with data of microscopic measurements and the results of the study of polydispersity in strong fiel ds based on the investigation of the relaxation of electrooptical effect.