The conditions for the formation of an anion-exchange layer of polyaniline on the surface of uncharged hydrophobic polytetrafluoroethylene film F-4SF were found. The effect of the F-4SF films pretreatment by different organic solvents for self-assembly synthesis of the PANI layers on an inert substrate was studied. Formation of PANI layers in the form of emeraldine salt leads to a change of the F-4SF surface properties towards hydrophilic from completely hydrophobic while also adding anion-exchanging properties. Obtained composite film F-4SF/PANI is highly sensitive towards pH value of a solution in which it is immersed, due to protonation-deprotonation reaction of the emeraldine salt. At the same time, this change in the chemical structure of the polyaniline is reversible, so composite material F-4SF/PANI can be used for development of optical pH sensors. (C) 2015 Elsevier B.V. All rights reserved.