Dynamic wetting: status and prospective of single particle based experiments and simulations

The fundamental molecular and microscopic properties of materials leading to dynamic wetting and relaxation effects have been subject to numerous studies in the past decades, but a thorough understanding is still missing. While most previous experiments utilize fluids deposited on planar substrates, this article focuses on an attractive alternative based on single colloidal particles: colloidal particles have the ability to strongly interact with fluid-fluid interfaces and the behavior strongly depends on the surface properties of the particles and the fluids used. Recent progress in the manipulation and synthesis of colloidal particles with well-defined surface properties and shapes makes them ideal candidates to probe the fundamental surface properties leading to dynamic wetting effects. In this paper we review and discuss the status of experimental and numerical techniques to characterize the dynamic wetting of single particles at fluid-fluid interfaces, with the aim to assist scientists and engineers in the design of new experimental techniques and particle-based (bio)analytical tools.