Measurement of contact angles at room temperature in high magnetic field

Abstract

The contact angle (CA) goniometer adaptable to a superconducting magnet was developed based on the sessile drop method. The goniometer mainly consisted of the sampling system, the supporting system, and the image acquisition system. Some improvements were taken to avoid the effects of the magnetic field (MF) on the CA measurement. As an example, the CAs of water on two substrates of silica and polymethyl methacrylate (PMMA) were measured using the goniometer. The results with and without a MF showed a good repeatability and reliability. Additionally, the MF was found to reduce the CA of water, which probably stemmed from the change of the surface tension in the MF. The CA goniometer will become an important tool which is used to study the wettability of liquids on a solid in the MF.

Reduced Wettability of Solids by a Liquid Ga–In–Sn Alloy in a Steady Magnetic Field

“…The present case is similar to the contact angle measurements of inorganic liquids in a SMF. 20 Thus, the magnetic force does not significantly contribute to the change in the contact angle.…”

“…The SMF intensity can be adjusted from 0 to 8 T. Details of the experimental setup were depicted elsewhere. 20 The contact angle was determined from the droplet profile using the software ImageJ with the plugin "dropsnake". The plugin was programmed using the spline snake approach developed by Stalder et al; 21 it is designed to determine the contact angles at the left and right sides of an asymmetrical drop.…”

“…The droplet was located in the center of the superconducting magnet, i.e., in the homogeneous magnetic field zone at its highest value. The SMF intensity can be adjusted from 0 to 8 T. Details of the experimental setup were depicted elsewhere …”

“…Its significance, e.g., in the field of electromagnetic processing of materials is unquestionable. Some researchers have developed experimental methods such as the surface-wave resonance method and the sessile drop method to explore the interfacial phenomena in an SMF. Among these methods, the sessile drop method provides a relatively simple and useful way for investigating interfacial properties of liquid metals in an SMF.…”

Wettability of Ionic Liquids in High Magnetic Fields

“…They have unique effects on many systems, especially the effect of the Lorentz force on charged ions and the effect of magnetic dipoles on the interfacial interaction . Recent studies have found that magnetic fields alter water contact angles. − Ren and Dueñas et al found that a static magnetic field reduced the contact angle of water, which probably stemmed from the change of surface tension in the magnetic field. Yin et al reported that the contact angle of water can increase in a simulated microgravity environment generated by a large gradient magnetic field.…”