Janus particles toward hierarchical functional coating and beyond

Janus particles (JPs) with two physically or chemically distinctive compartments can be employed as building blocks to achieve hierarchical functional coatings. For their amphiphilic property, JPs orientate at different interfaces of the as-formed coatings to enhance the interfaces and functionalize their surfaces. In this paper, we briefly review recent advances in JPs toward hierarchical functional coating and beyond. Since the requirements of economy and large-scale production, emulsion polymerization is an ideal method for the synthesis of JPs applied in coating industry. Ultrathin coating with single-layer particles can be directly fabricated with JPs self-orientating on the substrate. Furtherly, they are added into other latex coatings as an additive to adjust the microstructure, mechanical properties and functions of hierarchical coatings. In these methods, various functions are achieved such as superhydrophobicity, anti-corrosion, lubricity and so on. [Display omitted] •Janus particles produced by emulsion polymerization method have a potential for application in coating engineering.•Ultrathin coating with single-layer particles can be directly fabricated with self-orientation of JPs on the substrate.•Self-stratification of Janus particles in latex coatings has been observed and applied in hierarchical functional coatings.