Povrchová energie pevných látek
Klíčová slova:povrchová energie, rozpouštěcí kalorimetrie, DSC, měření kontaktních úhlů, Owensova-Wendtova metoda, Broken-bond, ab-initio výpočty
Surface and interfacial energies are crucial for most heterogeneous processes. They affect wettability and adhesion, adsorption, dissolution, nucleation, phase transformations and chemical reactions. The introduction of this work summarizes basic thermodynamic concepts about solid surfaces and interfaces between solid and liquid phases. In addition, two main methods for experimental determination of surface energies are introduced, namely calorimetry and contact angle measurement. Owens-Wendt method for the determination of surface energy from contact angles is discussed in detail and the determination of surface energy of polyethylene terephthalate is shown as an example. At the same time, the reasons why this method is not applicable to high energy surfaces of metals and oxides are presented. In the final part of the review, the possibilities of semiempirical and theoretical (ab-initio) methods that allow the calculation of surface energy are outlined.