Interfacial aspects of adhesion in polymer nanocomposite thin-film devices

Nanoscale polymeric composites are important in many new electronic technologies, including lightweight and flexible devices and sensors. The influence of surface chemical treatments, which particularly affect the adhesion properties of carbon-polyimide nanocomposite thin films, was studied with infrared spectroscopy, electron microscopy, atomic force microscopy, and contact angle measurements with respect to corresponding polyimide thin films. The contact angles showed that the inclusion of carbon initially increased the hydrophilicity, whereas a potassium hydroxide treatment increased the hydrophilicity of the pure polyimide film and the polyimide component of the nanocomposite surface without increasing the hydrophilicity of the carbon nanoparticle component. Friction-force atomic force microscopy was shown to be a powerful technique for confirming the relative wetting characteristics at the nanoscale. The lower hydrophilicity and activity of the carbon nanoparticles during adhesion reactions reduced the load at break, and this suggests that this conventional modification used for polyimides is less effective for their nanocomposite counterparts.