Carboxyl-rich coatings deposited by atmospheric plasma co-polymerization of maleic anhydride and acetylene.

Carboxyl coatings are extensively used for adhesion promotion, bio-immobilization and surface reactions thanks to their reactivity towards nucleophilic groups and high wettability. The deposition of relatively stable carboxyl-rich coatings using low-cost atmospheric pressure plasma processes is still challenging. This work is aimed at the investigation of the plasma copolymerization of maleic anhydride (MA) and C 2 H 2 by atmospheric pressure dielectric barrier discharge. The quantification of the carboxyl groups is performed by X-ray photoelectron spectroscopy (XPS) C1s curve fitting and by derivatization with trifluoroethanol. The layer synthesized at optimized monomer flow rate and plasma power contains 5 at.% of carboxyl groups (determined by derivatization combined with XPS) and exhibits the thickness loss below 5% after 128 h in water. The influence of the MA:C 2 H 2 ratio on the layer chemistry, morphology and stability is analyzed. [ABSTRACT FROM AUTHOR]