DYNAMIC MOBILITY SPECTRA OF MULTICOMPONENT COLLOIDAL SUSPENSIONS

Recently, the electrokinetic sonic amplitude (ESA) signal has been mea sured over a range of frequencies (collectively termed the dynamic mob ility spectrum) for the simultaneous determination of particle charge and size in moderately concentrated suspensions. Based on these advanc es, we develop theory describing the dynamic mobility spectra for mult icomponent suspensions, The dynamic mobility spectrum of multicomponen t suspensions can be interpreted as the weighted sum of the individual component dynamic mobility spectra. Weighting coefficients are define d and a methodology for determining these weighting coefficients for b inary suspensions with a least-squares technique is developed, Results from multicomponent suspension data are in good agreement with theory . Experimental conditions are restricted to constant pH and ionic stre ngth to avoid changes in the shape of the dynamic mobility spectra of the components, possibly due to agglomeration effects.