CHANGES IN THE SURFACE PROPERTIES OF INORGANIC-ORGANIC FILMS CAUSED BY WATER ATTACK

Abstract

The paper deals with studying the changes in the surface properties of inorganic-organic films after their interaction with water. The inorganic-organic films were deposited from sols, which were prepared at room temperature as well as the boiling temperature of isopropyl alcohol by three different ways of mixing the initial precursors - tetraethoxysilane (TEOS), triethoxy(octyl)silane (OTES), isopropyl alcohol, distilled water and nitric acid. The films, which were prepared by the dip-coating technique and treated at 170 °C, were exposed to a water attack at 80 °C for 5 hours. To characterise the films, after their interaction with water, changes in the morphology, rms-roughness and hydrophobicity were used. The studied properties were investigated, using the atomic force microscopy and sessile drop technique. All the films were hydrophobic, and their hydrophobicity was without any change or it was only slightly increased after the water attack. On the basis of the results, it can be stated that the way that the sol is prepared as well as the water attack have the smallest effect on the changes in the surface morphology of a film deposited from a sol where OTES was added to TEOS at the beginning of the sol preparation and they were hydrolysed simultaneously at room temperature. The rms-roughness and water contact angle for this film were only slightly increased after the water attack.

Keywords

• sol-gel
• inorganic-organic films
• water attack
• surface morphology
• hydrophobicity