Investigation of wettability alteration for droplets in microchannels through Experimental and Numerical Methods

Emulsions are mixtures of droplets in immiscible liquids like oil and water, capable of holding both hydrophilic and hydrophobic substances with applications from drug delivery to oil recovery. Wettability governs interfacial interactions, influencing droplet morphology, contact angles, and processes in membranes, soil transport, and nanomaterial assembly. This work studies nanoparticle-driven wettability alteration to shift s surfaces from oil-wet to water-wet, enhancing oil extraction. A microfluidic device is made to enable real-time visualization of droplet spreading and contact angle dynamics to evaluate the transition of surface wettability from oil-wet to water-wet states. Numerical simulations have also been performed within a corresponding microchannel geometry to replicate droplet behavior under different conditions. Computational fluid dynamics (CFD) simulations, based on the finite element method (FEM), replicate fluid behavior in microchannel geometries. The level set method (LSM) tracks oil–water interface evolution, providing quantitative insight into the fluid and surface interactions that drive wettability changes. This dual approach reveals nanoscale mechanisms of wettability change.