Understanding the self-replenishing of hydrophobic coatings for further industrial applications

Understanding the self-replenishing of hydrophobic coatings for further industrial applications

Zhang, Y.
Esteves, A.C.C.
Van der Ven, L.G.J.
Van Benthem, R.A.T.M.
De With, G.

2013-06-16

Hydrophobic materials hold many properties that are desirable in coatings, e.g. water repellency and low-adhesion are essential to achieve an easy-to-clean/ self-cleaning behavior. However, most of the coatings currently available cannot maintain their hydrophobicity upon surface damage or wear, due to the irreversible loss of the low surface energy chemical groups. This damage reduces the service-life time of coatings and limits its implementation on industrial applications. Therefore, the recovery of surface chemical groups is crucial for extending the service-life of hydrophobic polymeric coatings. One way to achieve this is to introduce a self-healing mechanism which can replenish the low surface energy groups at the surface after the damage. The proof-of-principle was previously reported for a “model” self-replenishing system based on a Poly(urethane) crosslinked soft (low-Tg) network with a small amount of fluorinated dangling chains [1]. In these systems the low surface energy dangling groups can re-orient towards the new air/coating interfaces created upon damaged. In this poster we report further studies in this model Poly(urethane)-based system which allowed us to clarify key details on the dynamics and kinetics of the selfreplenishing mechanism, e.g. the distribution of the dangling chains at the surface and in the bulk [2]. Furthermore, we will also discuss the clear drawbacks identified for the current model system which will restrict its direct industrial applications: 1) weak mechanical properties, e.g. low hardness (due to low Tg) and low solvent resistance. 2) there possibly existed the surface rearrangement due to the presence of hydrophilic ester part in the molecule. So the hysteresis of the coatings were high. 3) the current cross-linking procedure involves high temperature and long curing time.

coatings
self-replenishing
hydrophobic

http://resolver.tudelft.nl/uuid:8808435e-320a-4a74-a313-a93d25b4f2a3

Conference proceedings

conference paper

(c) 2013 Zhang, Y.; Esteves, A.C.C.; Van der Ven, L.G.J.; Van Benthem, R.A.T.M.; De With, G.