A One-Step Microfluidic Approach for Controllable Preparation of Nanoparticle-Coated Patchy Microparticles

In this work, we describe a one-step microfluidic method for fabricating nanoparticle-coated patchy particles. Janus droplets composed of curable phase and non-curable phase were produced via a co-axial microfluidic device firstly. Nanoparticles were dispersed into the continuous phase or the non-curable phase to realize the surface coating of the curable phase. The curable phase was then polymerized by UV light and nanoparticle-coated patchy particles were obtained. The SEM characterization shows that the particles are monodispersed with nanoparticle selectively distributed on the convex or concave surface. The dispersity, size and shape of the particles could be easily controlled by changing the microfluidic flow parameters. Three different types of nanoparticles were successfully used to synthesize the patchy particles to demonstrate the validity of the method.