Controlling self-patterning of acrylate films by photopolymerisation
Acrylate formulations can spontaneously generate surface patterns by UV-curing in open-air. This phenomenon, designated as self-patterning, occurs if there is a balance at the film surface between oxygen inhibition and polymerisation rates.
Indeed, to counterbalance the continuous oxygen diffusion at the film surface, polymerisation kinetics has to be very fast. It can be achieved using acrylate monomers which are characterised by very high propagation rate constants.
Tuning with crosslinker concentration
However, if the polymerisation kinetics is too fast (for example using very high UV intensities) oxygen inhibition is strongly reduced at the surface, preventing self-patterning. Finally, highly ordered and long-range morphologies, such as hexagons, peanuts or lamellae, can be obtained. Their type and size can be tuned with easy-to-handle parameters such as the crosslinker concentration and the film thickness.
The study is published in: Polymer Chemistry, Isuue 7, 2017.
