Recent advances in gel coatings: from lab to industry

The coating endows superwetting, biocompatibility, ionic conductivity and many other advanced functions of gel materials to traditional solids. Recently, many novel strategies for making gel coatings have emerged, targeting environmental adaptability, eco- and user-friendly demands, etc. In this review, we first summarize different types of interfacial interactions between gels and substrates. Then, general principles are discussed for preparing gel coatings on diverse solids with robust adhesion. Various practical attributes, such as oxygen tolerance and universal adhesion strategies are highlighted. Some promising applications of hydrogel and organogel coatings are mentioned. In the end, the current challenges and outlook of gel coating technology are discussed. The review summarizes and categorizes innovative gel synthesis methods and coating fabrication techniques with robust interfacial adhesion, focusing on the strategies of user and eco-friendliness in versatile scenarios.