Successive Redox‐Reaction‐Triggered Interface Radical Polymerization for Growing Hydrogel Coatings on Diverse Substrates

Growing lubricating hydrogel coatings in controllable manners on diverse material surfaces demonstrates promising applications. Here, a surface modification method is reported for in situ growing hydrogel coatings onto surfaces of diverse substrates in the absence of UV assistance. It is performed by decorating substrates with a universal mussel-inspired synthetic adhesive with catechol groups. Upon being immersed in reaction solution, these groups can assist substrate bonding and in situ capture and reduce Fe3+ into Fe2+ for decomposing S2 O82- into SO4- ⋅ catalytically at the interface to initiate interface polymerization of monomers. As a result, hydrogel coatings with controllable thickness could be grown on surfaces of arbitrary substrates to change their surface characteristics regardless of materials size, category, geometry and transparency, implying considerable potential in surface engineering.