New publication on the application of novel silane-polydopamine coatings

Check the latest publication of Giorgos Kafkopoulos and Vanessa Marinosci: Designer Adhesives for Tough and Durable Interfaces in High‐Performance Ti‐Carbon PEKK Hybrid Joints.

This study proposes the application of novel silane-polydopamine (Si-PDA) coatings as solution to enhance the long-term performance of titanium-thermoplastic composite joints in a hot/wet environment. For this purpose, the titanium alloy Ti6Al4V was pre-treated using three different coatings, namely a commercial silane coupling agent named APTES, PDA, and a combination of the two (Si-PDA coatings). Afterwards, the pre-treated titanium was bonded to C/PEKK composite using an autoclave co-consolidation process. The effect of each type of coating, before and after exposure to a hot/wet environment, was evaluated in terms of fracture toughness by means of a mandrel peel test.

Results demonstrate that the incorporation of APTES into PDA resulted in coatings that significantly improved the moisture resistance of titanium-C/PEKK joints, as they allowed to retain a high titanium-C/PEKK fracture toughness for longer time than uncoated joints.

In addition, X-ray photoelectron spectroscopy conducted on the crack surfaces suggests that Si-PDA coatings improved the moisture resistance of the titanium-C/PEKK interface as they reduce water diffusion, thereby delaying the water adsorption on titanium oxide.

Vanessa and Giorgos have performed this research at the TPRC in close cooperation with the Production Technology research group of Remko Akkerman and the Materials science and Technology of Polymers group of Julius Vancso, both from the University of Twente.

A special word of thanks goes to NWO (Dutch Research Council) for financing and supporting this research project.