Polydopamine nanocoating to use surface functionalization of polypropylenefabrics with a closed structure

In this study, an experimental investigation was conducted to explore polydopamine (PDA) nano-coating to use surface functionalization of polypropylene (PP) fabrics with a closed structure. Nanocoatings were made on polypropylene nonwoven fabric with the oxygen-induced polymerization method of dopamine (DA) at six different times. Uncoated control samples, coated samples and washed samples after coating were compared. A change in the solution towards a dark brown-black colour was observed during the experiment as the reaction time increased. Based on this finding, spectrophotometric measurements of samples were made. The lowest lightness and highest colour strength values were observed in fabric coated for 32 hours. In before and after washing SEM images, the formed nano-coating could be easily seen on this fabric (32 h). The nitrogen ratio indicating the presence of polydopamine was detected as 17.05%. After washing, it was observed that this high percentage decreased up to 1.35% but the nitrogen element was distributed homogeneously on the fabric surfaces from EDX mapping. FTIR analysis results confirmed that the PDA coating formed a bond with the polypropylene fabric and that these bonds continued after washing. Differently from uncoated fabric, extra bands and signals were observed in two different regions on the FTIR graph due to polydopamine. The results presented here may facilitate improvements in the surface activation of PP fabrics, which have a more closed structure for functionalization.