Wettability of a surface subjected to high frequency mechanical vibrations

Abstract

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.

Nano-biphasic calcium phosphate/polyvinyl alcohol composites with enhanced bioactivity for bone repair via low-temperature three-dimensional printing and loading with platelet-rich fibrin

“…The contact angle is the angle between the liquid-solid interface and the liquid-vapor interface. 36 …”

Volume and Frequency-Independent Spreading of Droplets Driven by Ultrasonic Surface Vibration

“…Prior work done with wetting driven by high-frequency vibration does exist [16,17,19,21,22], but many studies only provides a qualitative analysis that does not quantify the effect or elucidate the cause of the observed effects [16,17]. Many do not investigate a wide range of variables, but instead limit the study of certain variables (e.g., a fixed vibration frequency [16] and liquid properties [16,21]). In the author's prior work [23] wetting transitions were induced on smooth hydrophobic surfaces when droplets were vibrated with a swept sine wave input over a range of high frequencies (>10 kHz).…”

Dynamics of Nanodroplets on Vibrating Surfaces

“…It has recently been shown in macroscale experiments that the apparent wettability of a surface increases linearly with vibration amplitude a , but is independent of the vibration frequency f . Similarly, the magnitude of the (acoustic) pressure field within a macroscale drop increases during unidirectional motion of the substrate, and depends on the amplitude of vibration.…”