Revealing surface functionalities via microwave for the para-fluoro-Thiol click reaction

Abstract A fast and simple bottom-up methodology is reported to allow, thanks to a spontaneous phenomenon, the grafting of various materials on polymer substrates. In 60 s, the inert surface of polystyrene material is converted into a functional platform onto which organic molecules and metal particles can be anchored. A polystyrene (PS) matrix is blended with a small amount of a diblock copolymer additive engineered to both segregate at the material surface and be able to involve chemical reaction. Indeed, poly(penta fluorostyrene) (PSF) contains surface active fluorine atoms and the nucleophuge para-fluorine atom that allow nucleophilic substitution with thiols. Films of blend of PS matrix and PS-b-PSF additive are submitted to a microwave annealing to accelerate the spontaneous surface segregation of fluorine low surface energy atoms. XPS was performed to find that the optimal annealing condition was a treatment at 30 W during 60 s. With this procedure, a blend of 5 w% in additive can lead to a surface composed of 13 at% of fluorine atoms corresponding to 55 w% of diblock. The pentafluorostyrene units decorating the surface were used as anchors to immobilize gold nanoparticles via the para-fluoro-thiol click reaction.