Carlo Baldisserri

An analysis of current transients during electrophoretic deposition (EPD) from colloidal TiO2 suspensions

This is a simple quantitative analysis of the electrical current transients recorded during the electrophoretic deposition (EPD) of TiO(2) particles from ethanol-based suspensions in which the linear correlation between the mass deposited and the charge passed was verified experimentally. Using this experimental knowledge as our starting point, we were able to test a simple electrical model of a deposition cell for its consistency with electrical current density data measured during EPD. Assuming that the background electrochemistry was controlled resistively rather than diffusively, we then tentatively exploited the electrochemical data to gain information on the structure of the deposit during its growth.

A Controlled Colloidal Destabilization Approach for the Electrophoretic Deposition (EPD) from Cobalt Ferrite and Magnetite Nanoparticles Suspensions in Diethylene Glycol

Cobalt ferrite (CoFe2O4) and magnetite (Fe3O4) nanoparticles suspensions in diethylene glycol were tested as candidate systems for the EPD of CoFe2O4 and Fe3O4. It was found that despite the high stability and high zeta potential of such suspensions and the occurrence of mass transport at the electrode, they are not viable systems for EPD, due to coagulation failure. However, dilution of both suspensions with ethanol caused film coagulation at electric field between 20 and 60 V cm-1. Combinations of electric field and DEG volume fraction in ethanol/suspension mixtures that allow EPD to take place are detailed, and a description of the outcome of EPD trials is provided. A qualitative discussion of the causes of film consolidation in the presence of ethanol is presented.