Comparing Contact Angle Measurements and Surface Tension Assessments of Solid Surfaces

Dory Cwikel, Qi Zhao, Chen Liu, Xueju Su, Abraham Marmur

    Research output: Contribution to journalArticlepeer-review

    66 Citations (Scopus)

    Abstract

    Four types of contact angles (receding, most stable, advancing, and "static") were measured by two independent laboratories for a large number of solid surfaces, spanning a lam range of surface tensions. It is shown that the most stable contact angle, which is theoretically required for calculating the Young contact angle, is a practical, useful tool for wettability characterization of solid surfaces. In addition, it is shown that the experimentally measured most stable contact angle may not always be approximated by an average angle calculated from the advancing and receding contact angles. The "static" CA is shown in many cases to be very different from the most stable one. The measured contact angles were used for calculating the surface tensions of the solid samples by five methods. Meaningful differences exist among the surface tensions calculated using four previously known methods (Owens-Wendt, Wu, acid base, and equation of state). A recently developed, Gibbsian-based correlation between interfacial tensions and individual surface tensions was used to calculate the surface tensions of the solid surfaces from the most stable contact angle of water. This calculation yielded in most cases higher values than calculated with the other four methods. On the basis of some low surface energy samples, the higher values appear to be justified.

    Original languageEnglish
    Pages (from-to)15289-15294
    Number of pages6
    JournalLangmuir
    Volume26
    Issue number19
    DOIs
    Publication statusPublished - 5 Oct 2010

    Keywords

    • INTERFACIAL-TENSIONS
    • ROUGH SURFACES
    • FREE-ENERGY
    • HYSTERESIS
    • POLYMERS
    • FORCES

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