Stimuli sensitive grafted layers for switchable surface properties

COLL 501

K. Swaminathan Iyer and Igor Luzinov. School of Materials Science and Engineering, Clemson University, 161 Sirrine Hall, Clemson, SC 29634
The advantage of using "smart°± polymer coating is the ability to switch and/or tune the properties of the coatings by applying external stimuli. In this study, a new approach to switch properties is investigated using a polymer brush (polystyrene) grafted to a macromolecular anchoring interlayer, poly(glycidyl methacrylate) (PGMA). Carboxylic acid terminated polystyrene of different molecular weights from 4500 to 67200 g/mol were grafted from melt onto silicon substrates modified with the macromolecular anchoring layer. The thickness and the molecular weight of the anchoring layer were also varied. The unreacted epoxy groups of the macromolecular interlayer were reacted with ethanolamine, to increase the switchability of the nanolayer. The layers were characterized using scanning probe microscopy (SPM), ellipsometry and static contact angle measurements, after treatment with various solvents. Switching was found to be most effective for higher molecular weight PS grafted to thick macromolecular interlayer.