Wetting of ferrofluids: phenomena and control

TL;DR

This review explores the complex wetting behaviors of ferrofluids, emphasizing magnetic effects on contact angles and surface interactions, and highlights recent advances and future research directions in this field.

Contribution

It provides a comprehensive overview of ferrofluid wetting phenomena, focusing on magnetic influences and nanoscale interactions, and discusses new applications and research needs.

Findings

Magnetic fields significantly alter ferrofluid contact angles.

Nanoscale interactions influence ferrofluid spreading and wetting.

Recent literature reveals novel ferrofluid applications in microfluidics.

Abstract

Ferrofluids are liquids exhibiting remarkably strong response to magnetic fields, which leads to fascinating properties useful in various applications. Understanding the wetting properties and spreading of ferrofluids is important for their use in microfluidics and magnetic actuation. However, this is challenging as magnetically induced deformation of the ferrofluid surface can affect contact angles, which are commonly used to characterize wetting properties in other systems. In addition, interaction of the magnetic nanoparticles and solid surface at nanoscale can have surprising effects on ferrofluid spreading. In this review we discuss these issues with focus on interpretation of ferrofluid contact angles. We review recent literature examining ferrofluid wetting phenomena and outline novel wetting related ferrofluid applications. To better understand wetting of ferrofluids, more careful experimental work is needed.