Nanocomposite films prepared from stabilized aqueous SiO2 sols

• The stability of aqueous SiO2 sols in system “stabilized aqueous SiO2 sol–acetic acid–isopropyl alcohol.”
• The preparation of nanocomposite SiO2 films.
• The study of morphology, topography, adhesion forces and stiffness of films using AFM.
• Determination of relation between properties and composition of sols.

Using sol-gel method, the films containing appropriate nanoparticles have a wide range of application as protective, dielectric and superhydrophobic layers. The system “stabilized aqueous SiO2 sol–acetic acid–isopropyl alcohol” was used to study the possibilities of preparation of nanocomposite SiO2 films and their properties. The properties of surface of prepared films, such as morphology, topography and adhesion forces, were studied using atomic force microscopy (AFM). The contact angle of water and diiodomethane was measured to specify the polar and disperse components of surface tension. The changes in observed properties, mainly the difference of samples X4, X5 and X6, are explained on the basis of changes in stabilization process of sols used for films preparation. For the given observed properties, the determining process is the change from electrostatic to steric stabilization of studied sols.