This study shows that TiO2 nanofiller and cetyl trimethyl ammonium bromide (CTAB) surfactant in ester oil demonstrates higher corona inception voltage under AC and DC voltages. Flow electrification studies with nano fluid adopting the spinning disk method confirms that the streaming current increases with increasing pressboard thickness, disc diameter, oil temperature and spinning disk velocity. The study also indicates that nanofluids with surfactant have higher streaming currents than its effect without surfactant. It is found that the streaming currents could be suppressed by the addition of aromatic additive 1, 2, 3-benzotriazole (BTA). In addition, the permittivity of the nanofluid is not affected by adding surfactant or BTA but a marginal reduction occurs with increasing temperature. However, the loss tangent of the nanofluid with surfactant and BTA shows an increase with increasing temperature. The rheological studies indicate transition from laminar to turbulent flow in the case of nanofluids. © 1994-2012 IEEE.