Macroscopic control of DMAHEMA and HEMA plasma polymerization to tune the surface mechanical properties of hydrogel-like coatings

Macroscopic kinetics of DMAEMA and HEMA plasma polymerization have been investigated. Different regimes in the kinetics of growth have been identified and the resulting plasma polymer surfaces have been characterized by Infrared and X-ray photoelectron spectroscopies as well as by wettability analysis. Various hydrogel properties have been obtained leading to different surface mechanical properties. The values of Young's modulus estimated by AFM nanoindentation were found to be systematically high in the case of DMAEMA plasma polymerization (4-6MPa). However, in the case of HEMA plasma polymerization, the Young's modulus values could be tune to 1MPa up to 4.5MPa. This result was even more remarkable as chemical composition of the corresponding surfaces was quasi-identical.