AbstractCotton fabrics were treated by radio‐frequency plasma with tetrafluoromethane (CF4) and hexafluoropropene (C3F6) gases under different exposure times, pressures, and power levels. The hydrophobicity and water repellency were analyzed with measurements of the cosine of the contact angle (cos θ) and wet‐out time. The hydrophobicity was enhanced with treatments of both gases. X‐ray photoelectron spectroscopy (XPS) revealed increases in the surface fluorine content of 1–2% for CF4 plasma and of 2.3–7.8% for C3F6 plasma. The relative chemical composition of the C1s spectra after CF4 and C3F6 plasma treatments showed increases in the relative amounts of COC and fluorocarbon groups (CF, CF2, and CF3), whereas peak areas for COH and COOH decreased. The hydrophobicity was enhanced by the increase in the fluorine content and fluorocarbon groups. C3F6 plasma treatment resulted in higher hydrophobicity than CF4 plasma treatment according to not only cos θ and wet‐out measurements but also XPS analysis. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2038–2047, 2003
