Electrophoretic Deposition of Titania Nanoparticles: Sticking Parameter Determination by an In situ Study of the EPD Kinetics

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Author to whom correspondence should be addressed. e-mail: tshahrabi34@modares.ac.ir

Abstract

The suspensions of titania nanoparticles in isopropanol were prepared and triethanolamine (TEA) was used as a dispersant. Electrophoretic deposition (EPD) was performed at 60 and 200 V. In situ EPD kinetics was studied. During the in situ deposition weight recording, the voltage was switched off after 6 min and switched on again after 2 min with a reversed polarity. After voltage switch off the deposition weight decreased with time for the deposits formed from the suspensions with 0, 0.33, 1.33, and 6 mL/L TEA, due to the potential difference generated at the interface between the deposit and suspension, exerting a force on the particles strong enough to detach them into the suspension. The deposition weight remains nearly constant for deposits formed from the suspensions with 8 and 16.33 mL/L TEA, due to the lower potential difference and so the lower force exerted on the particles. It was assumed that particles detachment from deposit into the suspension also occurs during EPD and according to this assumption f factor (sticking parameter) at initial times of EPD was calculated. It was found that the f factor values calculated from the mentioned assumption have a good agreement with those calculated from the Hamaker equation.

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