Synthesis and applications of polymeric Janus nanoparticles

Abstract

Research into Janus particles has received great attention over the past decade. In his Nobel lecture in 1991, Pierre-Gilles de Gennes suggested that asymmetric colloidal particles with different chemical compositions on the two lobes could have a special behaviour at interfaces, and named them “Janus grains.1 Due to their asymmetry, Janus particles have the ability to offer more advanced chemical and physical properties compared to that of their symmetric homogeneous counterparts and in particular may behave as amphiphilic surfactants. However, for years after de Gennes’ Nobel lecture, research into Janus particles was still slow, as evidenced by the limited number of publications in the field. The main limitations to the advancement of the field were the difficulty in synthesising well-defined Janus particles and also in characterising them, especially in the case of nanometer-sized Janus particles. From around 2005, the significance of Janus particles in a wide range of applications has become clear, including in surfactants, electrochemistry, catalysis, electronics, sensors, optics, superhydrophobic textiles and nanomedicine, and this has driven research to pursue different methods for the fabrication of Janus particles. In the past ten years, Janus particles have become a hot topic of research, as evidenced by the exponential growth in the number of publications in this area. Our latest search using the keyword “Janus particles” on Web of Science shows 1,608 published research papers on this topic which is more than 16 times higher than in 2010.