Coalescence of surfactant-laden droplets

Abstract

Droplet coalescence is an important process in nature and various technologies (e.g. inkjet printing). Here, we unveil the surfactant mass-transport mechanism and report on several major differences in the coalescence of surfactant-laden droplets as compared to pure water droplets by means of molecular dynamics simulation of a coarse-grained model. Large scale changes to bridge growth dynamics are identified, such as the lack of multiple thermally excited precursors, attenuated collective excitations after contact, slowing down in the inertial regime due to aggregate-induced rigidity and reduced water flow, and a slowing down in the coalescence rate (deceleration) when surfactant concentration increases, while at the same time we also confirm the existence of an initial thermal, and a power-law, inertial, regime of the bridge growth dynamics in both the pure and the surfactant-laden droplets. Thus, we unveil the key mechanisms in one of the fundamental topological processes of liquid droplets containing surfactant, which is crucial in relevant technologies.

23 pages, 7 figures

References in corpus (5)

• Coalescence of bubbles and drops in an outer fluid
• Viscous to Inertial Crossover in Liquid Drop Coalescence
• The inexorable resistance of inertia determines the initial regime of drop coalescence
• Bridge evolution during the coalescence of immiscible droplets
• Coalescence of sessile polymer droplets: A molecular dynamics study

Cited by in corpus (6)

• Molecular dynamics simulation of the coalescence of surfactant-laden droplets
• Coalescence of sessile aqueous droplets laden with surfactant
• Many-Body Dissipative Particle Dynamics with the MARTINI "Lego" approach
• Collision of surfactant-laden droplets: insights from molecular dynamics simulation
• Nanoscale Surfactant Transport: Bridging Molecular and Continuum Models
• Coarse-Grained Model of the Sodium Dodecyl Sulfate Anionic Surfactant Based on the MDPD--Martini Force Field