Chapter 3. Flash Nano-precipitation and -complexation to Produce Polymer Colloids

Abstract

Polymeric colloids have garnered interest for their high surface area-to-volume ratio, tunable chemical functionality, and engineered responsiveness to stimuli. While promising for a diverse range of industrial applications, translating polymeric nanoparticles from the development phase to large-scale homologation requires high throughput, flexible, and economically scalable fabrication techniques. To this end, Flash NanoPrecipitation (FNP) and Flash NanoComplexation (FNC), both continuous processes, have been developed as candidates for industrial scale colloid production. In these techniques, mixing is achieved on a time commensurate with the time scales of hydrophobic polymer precipitation or polyelectrolyte complexation, thus enabling the controlled fabrication of nanoparticles and nanocomplexes, respectively. In this review, the working principles of both FNP and FNC are presented in addition to descriptions of current equipment configurations. Influence over particle size, morphology, and functionality is shown including the formation of core–shell particles via block copolymer adsorption, functional internally- and externally-structured particles through phase separation, and encapsulations of sensitive active pharmaceutical ingredients by electrostatic interactions. The simplistic operation and flexibility of both FNP and FNC highlights them as promising platforms for the future of colloid engineering.