Highly Water Repellent but Highly Adhesive Surface with Segregation of Poly(ethylene oxide) Side Chains

Polymer surfaces were modified using methacrylate terpolymers containing both perfluoroalkyl (R_<i>f</i>) groups and poly­(ethylene oxide) (PEO) as side chains in the same molecule. The structure and properties of the modified surfaces were evaluated using X-ray photoelectron spectroscopy and by measuring the dynamic contact angles and 90° peel strength. It was found that not only R_<i>f</i> groups but also PEO side chains were segregated on the surface being against the order of the surface free energy. The terpolymer modified surface is hydrophobic in air because R_<i>f</i> groups are predominant, but it becomes hydrophilic in water because the surface is covered with PEO side chains. This response to the environment is rapid and reversible. The modified surface showed high water repellency because of the surface R_<i>f</i> groups and high adhesive strength because of the side chains

Surfactant-Induced Polymer Segregation To Produce Antifouling Surfaces via Dip-Coating with an Amphiphilic Polymer

We propose a rational strategy to control the surface segregation of an amphiphilic copolymer in its dip-coating with a low-molecular-weight surfactant. We synthesized a water-insoluble methacrylate-based copolymer containing oligo­(ethylene glycol) (OEG) (copolymer <b>1</b>) and a perfluoroalkylated surfactant (surfactant <b>1</b>) containing OEG. The dip-coating of copolymer <b>1</b> with surfactant <b>1</b> resulted in the segregation of surfactant <b>1</b> on the top surface of the dip-coated layer due to the high hydrophobicity of its perfluoroalkyl group. OEG moieties of surfactant <b>1</b> were accompanied by those of copolymer <b>1</b> in its segregation, allowing the OEG moieties of copolymer <b>1</b> to be located just below the top surface of the dip-coated layer. The removal of surfactant <b>1</b> produced the surface covered by the OEG moieties of the copolymer that exhibited antifouling properties. Using this strategy, we also succeeded in the introduction of carboxy groups on the dip-coated surface and demonstrated that the carboxy groups were available for the immobilization of functional molecules on the surface