Intelligent coatings

Due to the intersectoral importance of paints for technological improvements in industry new developments in this field are likely to have explicit economic effects. Those improvements are initiated by the desire to implement new functions into coatings in order to create industrial goods with additional properties. A second driving force is given by the need to save energy and time and by forcing paint processing companies to reduce the use of volatile organic and hazardous compounds in coatings due to the environmental legislation of the European Community. Before nano-coatings can be adapted to industrial processes several main problems have to be solved such as the reduction of process costs, the achievement of reproducibility, an up-scaling to large substrate surfaces and the generation of long-term stable coatings.
For new functionalities of coatings and thin films, as smart, intelligent, switchable, actoric or sensoric the basic principles are currently investigated and the proof-of-principle has been done, but there is still a big deal of work to do to transfer these functional coatings into the industrial coating processes. Organic thin films are very promising to create those new functionalities.
Nanotechnological approaches using grafting techniques have advantages over other approaches to create thin functional films because of several reasons. They include easy and controllable introduction of polymer chains with a high surface density, precise localization of the chain at the surface, and long stability of the grafted layers. The use of polymer brushes is on the one hand a very promising mean to create surface functionalities as switchability or response to environmental conditions and on the other hand an effective manner to tune the relevant surface properties for many applications, as wettability, adhesion, lubrication, friction, biocompatibility or, for particles, colloidal stability. Mixed polymer brushes, which are experimentally investigated only recently, are created by grafting two incompatible polymers or a block-copolymer on the surface. When the film is composed of two incompatible polymers it is possible to switch the surface properties of the film between the properties of two individual polymers by external stimuli.

Scheme of the switching of a mixed brush layer

We are interested in the transfer of the concept of switching and adaptive thin films to industrial coating processes, which includes the manufacturing of polymer brush layers with robust and reproducible techniques and at extended surfaces.

Switchable transparent nanocoatings

Nanoparticle coatings for roll-to roll application

Anti-icing coatings

Video on the EISAB project "Aktive eisabweisende Oberflächen auf Rotorblättern" (German)