Poly(vinyl alcohol) with low surface free energy by fluorination

Poly(vinyl alcohol) (PVA) surface was fluorinated by simply immersing it in to a fluorinated silane coupling agent, 1H,1H,2H,2H-perfluorodecyltrichloro silane, methyl ethyl ketone solution. The contact angle of water for fluori nated PVA increased to 105 degrees after 48 h immersing. This value corresp onds to the surface free energy of 10 mJ/m(2), which is much lower than tha t of polytetrafluoroethylene, From atomic force microscope observations and X-ray photoelectron spectroscopy analysis, it is found that hydrophobicity is brought about by the covalently bonded fluorinated reagent on the PVA h im. In addition, fluorinated PVA showed a high resistance to water swelling . This fluorination technique is quite effective for lowering the surface f ree energy of PVA. (C) 1999 Elsevier Science Ltd. All rights reserved.