Nano- to micro-structured surfaces from amphiphilic copolymers

The present work deals with different classes of styrene-based amphiphilic copolymers with the aim to develop novel marine antifouling (AF)/fouling release (FR) coatings by making use of the antiadhesive properties of the coatings therefrom and avoiding any biocidal activity. Low elastic modulus and low surface energy of variously engineered fluorinated/siloxane copolymers were regarded as two important parameters to design effective coatings which prevent the adhesion of foulants and eventually release the attached organisms. The classes of amphiphilic polymers under consideration were represented by random copolymers derived from styrene monomers containing siloxane, fluoroalkyl and ethoxylated side chains, diblock copolymers derived from styrene and styrene monomers containing siloxane, fluoroalkyl and ethoxylated side chains, and triblock copolymers derived from styrene and styrene monomers containing siloxane, fluoroalkyl and ethoxylated side chains. The composition of the polymers was tailored to tune the amphiphilicity of each system by combination of the hydrophobic poly(dimethylsiloxane), hydrophilic poly(ethyleneglycol) and hydrophobic/lipophobic perfluoroalkyl stryrenic constituents. The polymers were characterized in terms of bulk and surface structures and properties. In particular, we investigated the surface properties and the role of surface segregation of fluorinated/siloxane side groups in a nanostructured surface and how it affected the surface behavior and reconstruction of polymer films. Moreover, in order to study the AF/FR performance of the polymers and establish correlations between surface properties and AF/FR properties, coatings were prepared by blending copolymers in a low amount in SEBS and PDMS elastomer matrices and were submitted to biological assays.