title: Nanoparticles adsorbed at the water/oil interface: coverage and composition effects on structure and diffusion.
abstract: Dissipative particle dynamics simulations are performed to study the structural and dynamical properties of various systems of nanoparticles accumulated at the water/oil interface. Homogeneous and Janus nanoparticles with different surface compositions are studied. For all nanoparticles, as the surface density increases, a transition from a liquidlike to a solidlike state is observed, as expected. At a high density of nanoparticles, hexagonal structures emerge and the nanoparticles' self-diffusion coefficient decreases because of caging effects. Similar results are observed for nanoparticles with different surface chemistry. Because different nanoparticles have different contact angles at the water/oil interface, the results obtained for systems containing mixed nanoparticles are more interesting. For example, our results show that the self-diffusion coefficient is not a monotonic function of the system composition, caused by the complex relation between hydrodynamic interactions and effective nanoparticle-nanoparticle interactions.
authors.affiliation: School of Chemical, Biological, and Materials Engineering, The University of Oklahoma, Norman, Oklahoma 73019, United States.
authors.forename: Xuan-Cuong
authors.initials: XC
authors.lastname: Luu
authors.forename: Jing
authors.initials: J
authors.lastname: Yu
authors.forename: Alberto
authors.initials: A
authors.lastname: Striolo
mesh_terms: D004058:Diffusion; D015394:Molecular Structure; D053758:Nanoparticles; D009821:Oils / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D009821:Oils; D014867:Water