Plasma Functionalization for Enhanced Natural Dye Affinity on Bioplastics: A Novel Approach

Bioplastics offer biodegradability and reduced environmental impact but often use nondegradable synthetic dyes. This study introduces a novel application of glow discharge plasma (GDP) technology to modify cassava starch-based bioplastic sheets, specifically optimizing conditions to enhance their hydrophilicity and adhesion for natural dyes. This research systematically tailors plasma treatment parameters to maximize the interaction between bioplastics and eco-friendly natural dyes. Optimal conditions, identified as 30 W for 3 min using oxygen, air, and nitrogen plasma treatments, demonstrate significant advancement in sustainable material development. Analyses (ATR-FTIR, EDX, XPS) showed increased concentration of polar functional groups and oxygen content, with FE-SEM and water contact angle measurements revealing improved surface roughness and wettability, respectively. Oxygen plasma treatment yielded the highest hydrophilicity and crystallinity of the polymer. Tensile tests indicated increased strength and decreased elongation. UV-Vis spectroscopy confirmed enhanced dye retention and reduced leaching. This study demonstrates GDP's potential to incorporate eco-friendly natural dyes into bioplastics, thereby contributing to the development of more sustainable materials.