Glow discharge plasma stabilization of azo dye on PMMA polymer.

The effects of argon gas glow discharge plasma on the surface of DR1 dye-loaded PMMA polymer films are examined in this work. Plasma immobilizes the dye on the surface of polymer without using stabilizers. Argon plasma activates the surface through breaking some bonds and generation of radical sites. It affects the acrylate groups of PMMA leading to covalent bonds between dye and surface of polymer. In addition, plasma treatment and contact with ambient air may result in the creation of new polar components, such as carbonyl and carboxyl compounds and links that enhance the dye attachment to the polymer matrix. Besides, the dye adsorption on the polymer film is impacted by changes in surface topography. Furthermore, plasma modifies the dye conformation, which affects the adherence of the dye to the polymer surface through bringing the dye to the higher energy state. The chemical and topographical modification of dye-loaded PMMA films by plasma are investigated by spectroscopic and AFM methods. Furthermore, aging process was used to confirm dye retention on the polymer film after plasma modification as opposed to dye-loaded polymer film that was left untreated as a reference sample. Finally, investigated method suggests a novel and very affordable technique for fabrication of poly(MMA-co-DR1) copolymer in the form of a homogeneous surface layer.