Аннотация:Poly(vinyl trimethylsilane) (PVTMS) films were subjected to direct surface fluorination inliquid medium (perfluorodecalin). The samples were investigated using several techniques: SEMXEDS, XPS, ATR-IR, and contact angle measurement. The methods used allowed us to estimatechemical changes occurring because of the treatment. ATR-IR showed that most of the changesoccurred in the Si(CH3)3 group. Monofluorinated Si(CH3)3 groups formed in the near-surface layer(Ge crystal, 0.66 µm penetration) after 30 min of fluorination, and then di- and trifluorinated groups appeared. Oxidation of the film with oxygen was also shown with the use of ZnSe crystal (2 µmpenetration). The XPS method allowed an assessment of the ratio of the main elements at the surfaceof the fluorinated film. Two different exponential models were proposed to fit the experimental dataof SEM-XEDS. Based on the model with the intercept, the depth of fluorination was estimated to be ≤1.1 µm, which is consistent with the result from the literature for the gas-phase fluorination.Contact angle measurements showed that oxidation of the PVTMS surface prevailed for the first45 min of fluorination (surface hydrophilization) with a subsequent fluorine content increase andhydrophobization of the surface upon 60 min of fluorination.