One-step, self-assembled highly oleophobic nanocomposite coatings

In a previous work, hybrid polymer/NP (nanoparticle) coatings with a homogeneous dispersion of NPs were realized by grafting amine-functionalized silica NPs onto associative thickening perfluorinated copolymers (HASE-F). Due to the presence of acid groups on the HASE_F copolymers, the grafting led to the formation of HASE-F/Si derivatives that will swell in water at neutral pH. Here, we report the post-grafting with perfluorinated acids RFn (C4F9, C6F13 and C8F17) in one step on the residual amine functionalities present on the NPs to afford HASE-F/Si/RFn derivatives. It was found that HASE-F/Si/RF8 is well dispersible in water at pH 7, and this suspension can be deposited by spraying and spreading techniques on a glass substrate. The new coatings display high oleophobic properties with olive oil contact angles up to 120 degrees, which is due to a spontaneous self-organization in nanosheets.