Marangoni effect

About: Marangoni effect is a research topic. Over the lifetime, 5336 publications have been published within this topic receiving 98562 citations. The topic is also known as: Gibbs–Marangoni effect.

The effect of compatibilizer on the coalescence of two drops in flow

Abstract: This paper reports results from an experimental study of the effects of copolymer/compatibilizer on the coalescence of two equal size drops in the flow field produced by a four-roll mill. The data encompass two different fluid systems, both with PDMS as the suspending fluid and PBd as the drops, and an acid-base complex of PDMS–NH3+ −OOC–PBd adsorbed at the interface that we shall refer to as a copolymer. The two systems differ in the ratio of viscosities (λ) of the drop to the suspending fluid, one having λ=0.19 and the other λ=1.3. For the lower viscosity ratio system, as the amount of adsorbed copolymer is increased, the drainage time for coalescence in a head-on collision is increased monotonically and the critical capillary number for coalescence in a glancing collision is also reduced monotonically in a manner that appears qualitatively consistent with a slowing of the film drainage process due to Marangoni stresses. Detailed trajectory measurements for drops with copolymer show agreement with predi...

Dynamic Control of Particle Deposition in Evaporating Droplets by an External Point Source of Vapor

Abstract: The deposition of particles on a surface by an evaporating sessile droplet is important for phenomena as diverse as printing, thin-film deposition, and self-assembly. The shape of the final deposit depends on the flows within the droplet during evaporation. These flows are typically determined at the onset of the process by the intrinsic physical, chemical, and geometrical properties of the droplet and its environment. Here, we demonstrate deterministic emergence and real-time control of Marangoni flows within the evaporating droplet by an external point source of vapor. By varying the source location, we can modulate these flows in space and time to pattern colloids on surfaces in a controllable manner.

Role of Marangoni stress during breakup of surfactant-covered liquid threads: Reduced rates of thinning and microthread cascades

Abstract: Simulations and experiments resolve a long-standing controversy that the gradient of surface tension---Marangoni stress---rather than surface tension lowering is responsible for decelerated thinning rates and microthread cascades during breakup of surfactant-covered threads.