Abstract
Various plasma polymerized organic acid thin films were obtained by using acrylic acid, p-toluenesulfonic acid or phthalic anhydride as an organic acid raw materials monomer, and their chemical structures and functionalities were investigated. Functional groups of organic compounds tend to be destroyed with increase of the plasma power output. There are two methods for the addition of various functionalities to material surfaces as follows : One is due to the residual functional groups derived from organic acid monomer in plasma polymerized thin films, and the other is the novel formation of functional groups by chemical reactions during plasma. As for the acrylic acid and p-toluenesulfonic acid, the decomposition of the hydrophilic functional groups such as carboxylic acid (R-COOH) or sulfonic acid (R-SO3H) resulted in influencing to their surface electric conductivity properties, because the amount of residual hydrophilic groups had an effect on the electrical characteristics of the thin film surface. The water wettability and adhesive properties of the plasma polymerized acrylic acid thin film changed due to the varieties of their chemical structures over the surface of the thin films. Plasma polymerized p-toluenesulfonic acid thin film showed the better response to the change of electrical conductivity on the thin film surface for the humidity.
