Scaffold for growing dense polymer brushes from a versatile substrate

We have demonstrated a universal approach to growing polymer brushes from various substrates. Urushiol was mixed with initiator-containing catechol, and it was spin-coated or cast on various substrates. Because urushiol is strongly adhered to various substrates, the thin film can serve as a general scaffold for grafting polymer brushes from various substrates. Note that the film was formed even onto the surface of polyolefins and thermosetting resins that are known as chemically inert materials to functionalize the surface. Moreover, the initiator-immobilized scaffold showed mechanical robustness and chemical inertness because of the flexible long unsaturated hydrocarbon side chain of urushiol. After the grafting of polyelectrolyte PMTAC polymer brushes, the material obtained exhibited hydrophilicity, typical of PMTAC. The concept shown here could provide a general approach for grafting practical polymer brushes from various substrates.