Effects of joule heating on electrophoretic mobility of titanium dioxide (TiO2), Escherichia coli and staphylococcus aureus (live and dead)

Abstract

Heating effects on surface charge of single cell bacteria was investigated. Selected samples were gram-positive strain of Staphylococcus aureus (S.aureus) and gram-negative strain of bacteria Escherichia coli (TiO2) were used in this study. Besides, control sample were chosen in this research was titanium dioxide (TiO2) due to the strong negative charges on it when suspended in solution. Surface charge of samples was determined by measuring the electrophoretic mobility and the zeta potential with laser Doppler velocimetry electrophoresis. Electrophoretic mobility of the materials was expected to increase as temperature increased due to the reduction of viscosity of the solution. This happened when temperatures of the solution increased, ions in solution move more randomly and causing the electrical double layer of charged particles and cells to diffuse greater. The electrophoretic mobility of control sample, TiO2 increased with temperatures, however both live and dead strain of E.coli and S.aureus had slight increased and the changes were erratic at various temperatures compared with TiO2. © 2011 Springer-Verlag.