Zisman plot interfacial tension

Surface tension Interfacial free energy mNm erg cm erg cm Contact angle (microscopy) Zisman plots Contact angle (degradation after prolonged UV irradiation) From isothermal crystallization studies At (2-D to 3-D) interface 16 16.5 16.5-14.4 30 10 (estimate) (53) (53) (54) (39)... 

Wetting and adhesion via the Zisman plot and theories for interfacial tensions... 

The various approaches motioned previously in this chapter can be used to estimate the surface tensions, e.g. of various polymers. Thus, polymer surface tensions have been reported using interfacial theories and contact angle data, from the critical surface tension (Zisman plot) and from extrapolating melt data to room temperature. There is relatively good agreement among the various methods for many polymers, within 4—5 mN m Some typical results are shown in Table 6.5. 

According to the Fowkes-Young theory for the interfacial tension and under the assumptions where = y, the Zisman plot is given by the equation ... 

There are two important approaches for studying wetting phenomena the Zisman s plot and the associated concept of the critical surface tension and the use of interfacial theories. These two approaches are presented in this section. The approach based on interfacial theories is somewhat more complex but provides more information. When combined with the Young equation for the contact angle (Chapter 4), interfacial theories can be used... 

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