Wettability of a surface subjected to high frequency mechanical vibrations

Ultrasonic radiation can modify some physical properties in liquid/solid interactions, such as wettability. The dependence of solid surface wettability on its vibrational state was studied. Experiments with an interface formed by distilled water deposited on a titanium alloy and surrounded by air were carried out. It is shown that it is possible to control the apparent wettability of a given liquid/solid/gas system by applying sonic-ultrasonic vibrations of controlled amplitude at the interface. The system studied is composed of a drop of distilled water deposited on a flat titanium surface in air. The contact angle was used as an indicator of apparent wettability. It is shown that the apparent wettability of a surface is linearly dependent on the peak vibration velocity and independent of the vibration frequency. Higher vibration speed lowers the contact angle and therefore causes greater surface wettability. (C) 2016 Elsevier B.V. All rights reserved.