Surface modification of water hyacinth fiber with ethanol pretreatment and argon plasma treatment
The non-reactive argon (Ar) plasma was used for surface modification of water hyacinth fiber (WHF). WHFs were rolled on a glass frame and put into the vacuum chamber with a 75W radio frequency (13.56 MHz) energy source with exposure times of 3 mins and 7 mins. Contact angle measurements (CA) with water and glycerine as test liquids, revealed that the samples become hydrophilic when exposed to Ar plasma for 7 mins with CA values of 0◦ and 67◦, respectively. Similarly, ethanol pretreatment showed a remarkable effect due to the introduction of polar atoms on the surface of WHF. On the other hand, the highest calculated total surface free energy of 117.7 mN/m was from the sample treated for 7 mins using Ar plasma. Our data showed that plasma-treated samples improved its wettability on polar liquids such as water was observed for plasma-treated samples. The longer the exposure to the Ar plasma, the better the WHF wettability. Moreover, ethanol significantly affects the sample's surface by increasing the surface polar component. Nevertheless, it was seen that Ar plasma treatment is an effective method to modify the surface of water hyacinth fibers for industrial applications.