Radio-frequency Ar plasma treatment on muga silk fiber: correlation between physicochemical and surface morphology

Radio-frequency (RF) Ar plasma treatment is carried out on natural muga silk fibers in a capacitively coupled plasmareactor. The physical and thermal properties of the muga fibers are investigated at an RF power of 20 W and in thetreatment time range of 5 to 20 min. The virgin and plasma-treated muga fibers are characterized by Fouriertransform infrared spectroscopy and X-ray photoelectron spectroscopy. The effect of Ar plasma treatment can beobserved only on the outermost layer of the muga fibers without any significant variation in their bulk and thermalproperties, as supported by differential scanning calorimetry and thermogravimetric analysis. Improvement in tensilestrength and hydrophobicity of the plasma-treated muga fibers is observed at lower treatment time and RF power.Attempts are made to correlate the properties of the plasma-treated muga fibers with their surface chemistry andsurface morphologies.

Keywords:

Radio-frequency plasma , Muga silk fiber , Peptide chain