Changes in the surface properties of plasma-modified polyfluoroolefin films during storage and heating

Surface modification of polyfluoroolefin films by glow discharge

“…2, curves 1а and 2а), whatever the chemical composition of the polymer, increases to a lesser extent. Even if lower θ values were obtained for films treated on the cathode, for example, for the PVDF film (curve 2c), a day after treatment the θ angle was higher compared with that for the same film modified on the anode (curve 2a) [12,20].…”

“…We also studied the effect of the temperature on the contact angle of the dc discharge-modified PTFE and F40 films [12] (Fig. 3).…”

“…According to the FTIR data [10,12,[19][20][21][22][23][24], the spectra of the modified polyfluoroolefin films differ from those of the starting films by increased intensity of bands at 1650-1900 cm -1 belonging to oxygencontaining groups and multiple bonds, as well as at 3500-3600 cm -1 assignable to the water adsorbed by the polymer film [16,17]. At 1600-1900 cm -1 , there are three well-defined bands (1880, 1720, and 1650 cm -1 ).…”

“…The XPS spectra of the PTFE films [12] allowed us to find out how the composition and structure of the films vary depending on their treatment conditions and on environmental factors. The spectrum of the starting film (Fig.…”

“…These results are consistent with the fact that the contact angles increase with time of storage. It is a common opinion that the increase in the θ angle of plasma-modified polymers as they are stored or heated is associated with thermodynamic relaxation processes, specifically, surface-to-bulk transfer of functional groups [10,12,[19][20][21][22][23][24][25][26][27][28].…”