Versatile synthesis schemes for diverse colloidal building blocks are essential to the continued development of self-assembled structures for fundamental studies in condensed matter and practical applications in advanced materials. While there are many techniques for colloidal synthesis, emulsion-based methods are ideal for large scale synthesis, but are often limited in chemistry and morphology. In our work, we design new emulsion-based syntheses that exploit polymerization-induced phase separation to control the structure and composition of anisotropic colloids. We will first demonstrate the synthesis of non-spherical polystyrene particles through the formation of pure-sided Janus particles and subsequent removal of a sacrificial phase. The particle shape is dictated by the intermediate Janus structure which we show can be controlled by choosing the appropriate sacrificial polymer, surfactant, and monomer ratio. In addition to controlling the shape of colloids, we can also tailor the chemical functionality through the use of click chemistry. We will show that we can synthesize clickable Janus particles containing a click-active acetylene moiety that can be functionalized through thiol-yne click reactions with commercially available thiols. Janus particles are modified to be amphiphilic by introducing either carboxyl, hydroxyl, or amine moieties. We also demonstrate that regulating the extent of the modification can be used to control the particle morphology, and thus the type of emulsion stabilized, as well as to fabricate composite Janus particles through sequential click reactions. Thiol-yne click chemistry offers a fast-reacting and modular synthesis method to transform clickable seed Janus particles. Our ability to design the structure and composition of diverse colloids will provide versatile new building blocks for self-assembly.<br/>

Seeded emulsion polymerization for non-spherical particles and clickable Janus colloids

253rd National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.