Solubility and adhesion characteristics of plasma polymerized thin films derived from lavandula angustifolia essential oil

Abstract

Integration and implementation of organic polymer thin films often require knowledge of the stability when in contact with solvents and the adhesion quality when applied to different substrates. This article describes the solubility and adhesion characteristics of organic polymer thin films produced from Lavandula angustifolia essential oil, using radio frequency plasma polymerization at four RF power levels. Contact angle data was obtained for various solvents and used to determine the surface tension values for the polymer by using three established methods. A relatively strong electron–donor component and a negligible electronic acceptor component for the polymers indicate that they are monopolar in nature. Solubility data derived from interfacial tension values suggest that the polymers would resist solubilization from the solvents explored. The strongest solvophobic response was assigned to water, whereas diiodomethane demonstrated the weakest solvophobic response, with ΔG121 > 0 in some instances depending on the surface tension values used. The adhesion tests of the polymers deposited on glass, PET, and PS indicated that the adhesion quality of the thin film improved with RF power, and it was associated with an improvement in interfacial bonding.