Janus nanoparticle synthesis: Overview, recent developments, and applications

Abstract

Janus nanoparticles (JNPs) have two faces with differing physical or chemical characteristics which endow them with unique properties. This anisotropy can lead to phenomena like self-assembly or interfacial activity, and JNPs have been under intense scientific scrutiny since the 1990s. Since then, powerful synthetic techniques have been developed which allow for JNPs with near limitless combinations of materials, properties, and morphologies. As such, JNPs have been featured in a number of applications such as drug delivery, catalysis, interfacial engineering, and optics. This perspective discusses the synthesis of these important anisotropic materials. We will focus exclusively on JNPs that involve polymers. In particular, we outline the various classes of JNP synthetic techniques including some historical context, describe recent developments in this area, and weigh the pros and cons of the different methods with an eye on future directions and applications. We hope this perspective will help acclimate those new to the field who want to make and/or use JNPs.