An Aggregation Model for Flash NanoPrecipitation

Flash NanoPrecipitation is a novel approach for producing functional nanoparticles stabilized

by amphiphilic block copolymers. A microscale multi-inlet vortex (MIV) reactor is utilized for

this process because of its mixing performance and flexibility. During this process, the particle

size distribution is frozen and stabilized by the amphiphilic di-block copolymer on the organic

particle surface. That is, the particle growth is kinetically arrested and thus a narrow particle

size distribution can be attained. To model the precipitation process, a bivariate population

balance equation (PBE) has been formulated to account for co-precipitation of the organic and the

block copolymer. Aggregation rate kernels have been derived to account for the major different

aggregation events: free coupling, unimer insertion, and aggregate fusion. The resulting PBE is

solved both by direct integration and by using the quadrature method of moments.