Deformation and rupture of Janus nanoparticle-stabilized Pickering emulsion in confined channel

Abstract

The interaction between Pickering emulsions and confined channels is vital for their industrial applications. However, how solid particle shells modulate the deformation stability and rupture limit of Pickering emulsions in contact with wall remains poorly understood. In this work, mechanical deformation and rupture of Janus nanoparticles (JNP)-stabilized Pickering emulsions on solid surfaces are elaborated by molecular dynamics (MD) simulations. A universal master-type predictive model is developed for the first time to describe the contact behavior of Pickering emulsions against surfaces with distinct wettability. The contact stress of an emulsion is determined by the equivalent elastic modulus of the emulsion, geometric deformation function, and the influence of the JNP shell and its interactions. Moreover, hydrophobic surfaces lead to the rupture of Pickering emulsions in compression. The rupture can be delayed by increasing JNP surface coverage (ϕ). Especially, once ϕ reaches a critical value, the JNP shell can form an ordered quasi-solid structure, significantly enhancing the emulsion stability. These results can aid in the design or screening of specific Pickering emulsions to manage their deformation and rupture on the solid surface, in applications ranging from water treatment and drug delivery to environmental remediation and mobility control in oil recovery.