Abstract
Research into the micro-nanostructured coatings process has made a variety of new applications available. Electrophoretic deposition (EPD) is an efficient and attractive technique to produce coated materials. Therefore the understanding of the formation and growth mechanism of the coating process continues to be investigated. In this study, a home-made EPD laminar flow cell was used for in-situ investigation of the particle velocity and deposition of micronic particles on a cathode. Monodisperse polystyrene latex particles were functionalized with cationic surfactants: cetyltrimethyl ammonium bromide (CTAB) or cetyltrimethyl ammonium chloride (CTAC). The tangential velocity of the particles when they migrated to the electrode, the approach angle and the tangential velocity along the electrode were measured under a DC electric field. From the values of the velocities, the particle-electrode distance was evaluated in CTAB and CTAC solutions. The electrophoretic velocity was calculated from the electrophoretic mobility of the particles and the electric field applied to the particles. All these parameters depend on the type of surfactant counter-ions and influence the growth of the coating. Dense structures were obtained in CTAB solution while open structures were observed in CTAC solution.
Highlights
An expanding area in materials processing is the controlled assembly of colloidal particles on a substrate
4 represents thethe z-position of of different particles moving along thecathode cathode(placed vertically)asasaafunction function of of time for particles different particles moving along the particles dispersed in cetyltrimethyl ammonium bromide (CTAB) solution
We found a distance below 1 nm in the 5 × 10−4 M cetyltrimethyl ammonium chloride (CTAC) solution and of about 20 nm in the 5 × 10−4 M CTAB solution
Summary
An expanding area in materials processing is the controlled assembly of colloidal particles on a substrate. The production of these materials is of interest in a large range of applications, such as composite coatings, adhesion of paints, optical devices, optoelectronic materials, biological and chemical sensors. Long-range interactions between particles near an electrode have been observed and explained by local electro-osmotic and electro-hydrodynamic fluid flow around a deposited particle [11,12,13,14,15]. Using a specific home-made apparatus, we observed this effect on the growth of particle aggregates near a cathode and we used it to obtain a high surface coverage in a laminar flow cell [16]. A complete understanding of Coatings 2017, 7, 147; doi:10.3390/coatings7090147 www.mdpi.com/journal/coatings
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
