Contact angles of water, formamide, methylene iodine and 1-bromonaphthalene on POM and PTFE

Abstract

The contact angle values (θ) on the surfaces of polytetrafluoroethylene (PTFE) and polyoxymethylene (POM) were determined using the sessile drop technique. A laboratory-made and calibrated goniometer was employed for this purpose*. The contact angles were measured in a static condition, meaning that the contact line between the solid, vapor, and liquid phases of the droplet remained stationary with respect to the surface of the solid. The probe liquids used in the experiment were deionized water (Wa), formamide (Fo, >99.5%, Biopack), methylene iodine (Mi, >99%, Sigma-Aldrich), and 1-bromonaphthalene (Br, >95%, Merck). Drops of 2 µL were deposited onto the surface using a micropipette. The contact angle was measured between 5 and 10 seconds after the drop was deposited on the surface. For each probe liquid, 12 drops were deposited and measured on each surface. *https://doi.org/10.1016/j.ijadhadh.2018.10.012