age, if it occurs, appears to be irreversible. Flocculation The kinetics of conformational changes of a series of partially controlling processes such as diffusion and adsorption of hydrolyzed polyacrylamides (HPAM) adsorbed on alumina in polymers are believed to be very rapid; however, one imaqueous solutions was studied along with the flocculation of aluportant parameter, polymer conformation, can take much mina. After the polymer was adsorbed, the conformation of the longer to reach equilibrium. The conformational rearrangeadsorbed polymer was changed by shifting the suspension pH. It ment of adsorbed polymer species due to changes in suspenwas found that the kinetics of the polymer conformational change sion properties also can be expected to be very slow, since was dependent upon the hydrolysis degree and the molecular many segments of a polymer chain are bound to the surface weight. It was found that while under fixed pH conditions the of particles at any given time (5). Information on both such flocculation continuously decreased apparently due to floc breakage; under shifted pH conditions (from low to high) it went changes and the resultant effect on flocculation and stabilizathrough a maximum as a function of time. When the effects of tion are lacking.
floc breakage caused by agitation are isolated and accounted for
In this study, changes in alumina flocculation with parthe flocculation is found to correlate well with the conformational tially hydrolyzed polyacrylamides due to pH perturbation of changes in the system. It is proposed that the unusual flocculation the system were studied as a function of mixing time after time dependence obtained under the shifted pH condition is caused polymer adsorption along with conformational changes of by the combination of the beneficial effect of the predominant the adsorbed polymer species. The goal was to elucidate the polymer conformational changes and the detrimental effect of floc role of the time effects of the conformational changes of breakage by agitation.