Nanoscale surface morphology of plant fibers has important implications for the interfacial bonding in fiber-polymer composites. In this study, we investigated and quantified the effect of plasma-surface modification on ramie plant fibers as a potential tool for simple and efficient surface modification. The extensive investigation of the effects of plasma treatment of the fiber surface nano-morphology and its effect on the fiber-polymer interface was performed by Low-Voltages Scanning Electron Microscopy (LV-SEM), infrared spectroscopy (FT-IR) analysis, fiber-resin angle measurements and mechanical (tensile) testing. The LV-SEM imaging of uncoated plasma treated fibers reveals nanostructures such as microfibrils and elementary fibrils and their importance for fiber mechanical properties, fiber wettability, and fiber-polymer matrix interlocking which all peak at short plasma treatment times. Thus, such treatment can be an effective in modifying the fiber surface characteristics and fiber-polymer matrix interlocking favorably for composite applications.
Keywords: LV-SEM; microfibrils; nanoscale structures; plasma treatment; ramie fibers; surface wettability.