Investigation of Contact Angles of Oil/Water Droplets through Oily Wastewater Separation

Hypothesis: Although the interactions of oil and water droplets with substrates have been extensively studied at the macroscale, fundamental investigations at the nanoscale, particularly regarding the effects of interfacial surface modifications, remain limited. To address this limitation, a polyurethane-based surface was designed and employed for oil/water separation applications. The behavior and motion of oil and water droplets on this surface were evaluated, and the contact angles were calculated both before and after surface modification with zinc stearate nanoparticles. Methods: Molecular dynamics simulations were performed to investigate the behavior of oil and water droplets on the surfaces, and the simulation results were compared with experimental contact angle measurements. Simulations were conducted using the LAMMPS and Materials Studio software packages. Findings: The modified polyurethane surface exhibited superhydrophobic and superoleophilic characteristics, with a water contact angle (WCA) >۱۵۰° and oil contact angle (OCA) <۵°, thereby enhancing oil affinity and promoting efficient separation. A strong correlation was observed between the nanoscale simulation results and the macroscale experimental measurements. These findings offer valuable insights into droplet dynamics on superhydrophobic surfaces and demonstrate the potential of molecular dynamics simulations for predicting and understanding the mechanism of oil/water separation at the molecular level.

کلیدواژه ها:

Molecular Dynamics Simulation ، LAMMPS software ، Droplet motion ، Contact Angle ، Superhydrophobic Surface ، Superoleophilic Surface