Deposition of latex particles encapsulated in polyelectrolyte shells at heterogeneous metal surfaces modified by multilayer films

Abstract

We used an oblique impinging jet (OIJ) cell to determine the initial deposition rate for the microcapsules deposited on the heterogeneous metal surfaces bare or modified by polyelectrolyte (PE) films. The dependence of reduced particle flux on the Reynolds number of the flow in the OIJ cell was determined by direct counting of particles deposited on the studied surfaces. We used fluorescently labelled latex particles and microcapsules built on these fluorescent cores and the use of fluorescent microscope allowed us to observe “in situ” the deposition processes of particles on rough, highly reflective surfaces. We demonstrated that modification of metallic surfaces of various materials and heterogeneity by the multilayer PE films result in the formation of uniformly charged film of nanometers thickness. The formation of such a film leads to the increase of deposition efficiency and its initial rate is governed by the charge of the film covered surface and the outermost layer of the capsule shell being in agreement with the prediction of the convective-diffusion theory.