Simple Method to Produce Janus Colloidal Particles in Large Quantity

TLDR

The study presents a simple, generalizable, inexpensive method for large‑scale synthesis of Janus colloidal particles. Janus particles are formed by adsorbing untreated particles at the wax–water interface, freezing the wax, chemically modifying the exposed surfaces, dissolving the wax, and then modifying the inner surfaces. The method yields gram‑scale or larger quantities of Janus particles.

Abstract

A simple, generalizable, inexpensive method is demonstrated to synthesize Janus colloidal particles in large quantity. At the liquid−liquid interface of emulsified molten wax and water, untreated particles adsorb and are frozen in place when the wax solidifies. The exposed surfaces of the immobilized particles are modified chemically. Finally, wax is dissolved, and the inner surfaces are modified chemically. Gram-sized quantities or more of Janus particles can be synthesized by taking this approach.