Chiang Mai Journal of Science

     A diverse range of monomers is commonly used in processes involving the deposition of carboxylic acid functional groups onto surfaces. These processes support various applications for polymeric materials, including the development of antibacterial coatings, improved biocompatibility, controlled surface wettability, use in environmental filtration systems, and enhanced interfacial adhesion in composite materials. In the field of biomedical engineering, polyethylene terephthalate (PET) has attracted increasing interest as a scaffold material. However, its inherent hydrophobicity and chemical inertness present challenges for imparting antibacterial functionality. To address these limitations, this study introduces an innovative and eco-friendly technique utilising a remote atmospheric pressure plasma (rAPP) system. Within this setup, acrylic acid (AAc) and acetic acid (AA) are used as chemical precursors to deposit carboxylic acid groups onto the PET surface. This method enables rapid and effective surface modification without damaging the underlying material. The research provides a detailed evaluation of surface wettability, stability of hydrophilicity, chemical composition, and antibacterial activity of PET treated using both AAc- and AA-based rAPP treatments. Results indicate that AAc, in particular, leads to significantly enhanced surface hydrophilicity, evident from a reduction in water contact angle from 74.4 ± 2.6° to 23.3 ± 0.6° and a stable presence of carboxylic acid groups. Furthermore, improved antibacterial performance (90 %) was observed on rAPP-functionalized PET samples without being cytotoxic when compared to PET Neat, highlighting successful PET surface functionalization for antibiotic-antimycotic coatings.