Modelling of self-healing surface structures coatings

Modelling of self-healing surface structures coatings

Lyakhova, K.
Esteves, A.C.C.
De With, G.

2013-06-16

For many current engineering applications the performance of materials depends strongly on the surface properties of the top layer. In many cases a hydrophobic/superphydrophobic top surface is desired (for example for easy-toclean/ self-cleaning applications). The durability of coatings will be substantially extended if the layer which provides the hydrophobic/superhydrophobic property will have ability to self-heal. Previously, hydrophobic coatings with a self-healing surface were reported by our group. These coatings can recover a sufficiently high concentration of the lowsurface-energy groups at the air/polymer interface. The bulk material serves as reservoir of the low-surface energy component (fluorinated polymer dangling chains). A mechanism of self-replenishing involves the reorientation of the dangling chains which carry the fluorinated group. Silica particles where incorporated into the polymer system in order to introduce the surface roughness leading eventually to higher contact angles of the polymer coating. Our goal is to create a model of the a selfhealing superhydrophobic coating. In this work we use the mesoscopic modelling technique (dissipative particle dynamics) in order to study several aspects of these polymer/particle coating: 1) the segregation of the low surface energy groups at the top surface of the coating.; 2) the self-healing response of the system and 3) the dynamics and distribution of crosslinks in the polymer system in presence of relatively large silica particles. For these studies we considered the distribution of the low surface energy groups in a confined geometry at the interfaces available. The minimal thickness of the polymer layer which provides self-healing ability was also calculated. All the relevant parameters (crosslinking conditions, polymer precursor and dangling chain length and distance between particles) were changed systematically. The simulations give a valuable insight into the details of microstructures and dynamics and guide experiments towards the choice of the system with the maximal selfhealing efficiency.

self-healing polymer coatings
simulation
mesoscopic modeling
hydrophobic coating
low-surface energy component

http://resolver.tudelft.nl/uuid:769493d9-fb12-47ff-97ad-0fcbacd6a036

Conference proceedings

conference paper

(c) 2013 Lyakhova, K.; Esteves, A.C.C.; De With, G.