Tridodecylamine, an efficient charge control agent in non-polar media for electrophoretic inks application.

In order to obtain efficient electrophoretic inks, Tridodecylamine (Dod 3 N), has been studied as charge control agent (CCA) in a non-polar paraffin solvent (Isopar G) for various inorganic pigments (TiO 2 and Fe 2 O 3 ). All hydrophobic mineral oxides, i.e. treated with octyltrimethoxysilane (C8) or dodecyltrimethoxysilane (C12), were found to be negatively charged in presence of Dod 3 N. The electrophoretic mobilities of inorganic pigments seemed to be strongly dependent of their isoelectric point (IEP) and also of the concentration of dod 3 N with an optimum range between 10 and 20 mM depending on the pigments. Finally, an electrophoretic ink constituted of hydrophobic mineral oxides in presence of Dod 3 N was tested in a device. Its efficiency as charge control agent to negatively charge hydrophobic particles was confirmed through good optical properties and fast response time (220 ms at 200 kV m −1 ). [ABSTRACT FROM AUTHOR]