The ability to control interactions between polymeric substrates and a single molecule including successful placement of single molecules in desired spatial locations whilst maintaining technologically useful conformations, provides a platform for engineering functional surfaces designated for high-tech devices and products. Â Subsequent understanding and control of interactions between immobilized molecular brushes and interacting fluids, solids or bio-active materials facilitates the control of adhesion and fracture properties of interfaces for structurally bonded or coated materials, or provides the control of other properties such as surface conductivity of flexible films for electronic or energy harvesting applications, or live cells propagation in bio-medical devices.
We demonstrate in this paper that surface grafted molecular brushes of controlled surface density, spatial geometry and chemical functionality facilitate more than 1000-fold strength increase of bonded assemblies in comparison with unmodified substrates, to the point of 100% cohesive fracture of substrates or adhesives. The use of molecules exhibiting an in-built electron conductivity facilitates up to a 108-fold increase in polymers surface conductivity. The long-term retention of surface functionality, e.g. bondabillity, surface conductivity or bio-compatibility are also achieved through the use of surface grafted molecular brushes.
