Short-time self-diffusion of nearly hard spheres at an oil–water interface
نویسندگان
چکیده
Optical microscopy and multi-particle tracking are used to study hydrodynamic interactions of monodisperse polymethylmethacrylate (PMMA) spheres at a decalin– water interface. The short-time self-diffusion coefficient measured at low surface coverage has the form D S (n)=αD0(1−βn), where n is the area fraction occupied by the particles, and D0 is the Stokes–Einstein diffusion coefficient in the bulk suspension of PMMA spheres in decalin. The measured values of α are found to be in good agreement with the numerical calculation for the drag coefficient of interfacial particles. The measured values of β differ from that obtained for bulk suspensions, indicating that hydrodynamic interactions between the particles have interesting new features at the interface.
منابع مشابه
A fast and simple method for modeling of oil swelling in Co2 injection
In this paper, the role of molecular diffusion in mobilization of waterflood residual oil is examined. A moving mesh method is applied to solve the moving interface problem of residual oil blobs swelling by Co2 diffusion through a blocking water phase. The results of this modeling are compared with experimental results of a 2D glass micromodel experiment. Although, the solution method is applie...
متن کاملLong-time dynamics of concentrated charge-stabilized colloids.
Dynamic light scattering was used to study the dynamic structure factor, S(q,t), of suspensions of charged colloidal silica spheres over the full colloidal time range. We show that a dynamic scaling relation for S(q,t) found by Segrè and Pusey [Phys. Rev. Lett. 77, 771 (1996)10.1103/PhysRevLett.77.771] for hard spheres, relating long-time and short-time dynamics, and collective and self-diffusi...
متن کاملAn Experimental Investigation of Water Effects on Asphaltene Surface Behavior through Interfacial Tension Measurements
As a physiochemical property, asphaltenes are known to be one the most surface active compounds in crude oil. Due to such property, their behavior is most probably influenced by fluid-fluid interactions at the contact surface (interface). Potentially and naturally, in most cases, water is in contact with crude oil and is co-produced with it as well. Considering that asphaltene molecules are pol...
متن کاملElectro-Coalescence of an Aqueous Droplet at an Oil–Water Interface with an Investigation of Secondary Droplets Formation
متن کامل
Structure, diffusion, and permeability of protein-stabilized monodispersed oil in water emulsions and their gels: a self-diffusion NMR study.
Self-diffusion NMR is used to investigate monodispersed oil in water emulsions and the subsequent gel formed by removing the water through evaporation. The radius of the oil droplets in the emulsions is measured using a number of diffusion methods based on the measurement of the mean squared displacement of the oil, water, and tracer molecules. The results are consistent with the known size of ...
متن کامل