Abstract
Heteroaggregation and homoaggregation is investigated with time-resolved multi-angle dynamic light scattering. The aggregation rates are measured in aqueous suspensions of amidine latex (AL) and sulfate latex (SL) particles in the presence of sodium octyl sulfate (SOS) and sodium dodecyl sulfate (SDS). As revealed by electrophoresis, the surfactants adsorb to both types of particles. For the AL particles, the adsorption of surfactants induces a charge reversal and triggers fast aggregation close to the isoelectric point (IEP). The negatively charged SL particles remain negatively charged and stable in the whole concentration range investigated. The heteroaggregation rates for AL and SL particles are fast at low surfactant concentrations, where the particles are oppositely charged. At higher concentrations, the heteroaggregation slows down above the IEP of the AL particles, where the particles become like-charged. The SDS has higher affinity to the surface compared to the SOS, which induces a shift of the IEP and of the fast aggregation regime to lower surfactant concentrations.
Highlights
Aggregation of particles in suspensions is important in many practical applications, such as ceramic processing, paint fabrication, or drug formulation [1,2,3,4]
We report experimentally measured homoaggregation and heteroaggregation stability ratios in aqueous suspensions of amidine latex (AL) and sulfate latex (SL) particles in the presence of two different alkyl sulfate surfactants, namely sodium octyl sulfate (SOS) and sodium dodecyl sulfate (SDS)
We investigate the influence of two alkyl sulfate surfactants on homoaggregation and heteroaggregation involving SL and AL particles
Summary
Aggregation of particles in suspensions is important in many practical applications, such as ceramic processing, paint fabrication, or drug formulation [1,2,3,4]. Many of these applications involve a mixture of different types of particles. This fact implies that one needs to understand homoaggregation (i.e., aggregation between similar particles), and heteroaggregation (i.e., aggregation between dissimilar particles). Some quantitative studies of heteroaggregation involving oppositely charged particles have been published recently [5,6]. Few studies analyze such systems quantitatively [7,8,9,10]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
