Studying effect of various stabilisers on sol electrophoretic deposition of titania

Abstract

In this work, titanium dioxide was coated on a metallic substrate using sol electrophoretic technique. Titanium dioxide particles were synthesised by hydrolysis and condensation of a precursor in a colloidal solution. The particles were suspended in the solution using electrostatic [hydrochloric acid (HCl)], steric [polyvinyl butyral (PVB)] and electrosteric [polyethyleneimine (PEI)] stabilisers and were coated on an electrode using an external direct electrical field. The pH, conduction and stability of the suspensions, deposition rate and the current versus time changes were monitored for suspensions containing different stabilisers. Low surface potential of the steric stabilisation and low conduction of the solution led to no film formation for solutions containing PVB. The highest zeta potential was achieved by addition of PEI as the stabiliser. The optimum applied voltage for pure, uniform and crack free titanium dioxide films was 6 V for suspensions containing PEI and 3 V for those containing HCl.

Keywords:

• EPD
• Sol–gel
• Titanium dioxide
• Stabiliser
• Zeta potential

The authors appreciate the financial support of Research Committee of Shiraz University in the form of research grant no. 90-GR-ENG-104 given to Professor M. Javidi.