Janus Particles and Interfacial Activity

Abstract

Janus particles are colloids with two different spatial domains. When these domains are synthesized with a contrast in wettability the particle shows an enhanced interfacial activity in comparison with the corresponding homogeneous particles. There are different synthesis routes to fabricate such particles. One of the most common is to start with a homogeneous particle and functionalize just one hemisphere of the particle or form the particle directly with two compartments, the so-called true Janus particles. Other particles which rely on the phase separation during synthesis are rather considered Janus-like particles. The Langmuir balance and the pendant drop tensiometry are useful to characterize the interfacial activity of the Janus and homogeneous particles at liquid interfaces.