Modification of nano carbon black particles to obtain surface charge for electronic ink

The surfaces of nano carbon black particles were modified by silane coupling agent 3-triethoxysilylpropylamine (KH550) and concentrated sulfuric acid. Manifested by transmission electron microscope, ultraviolet-visible spectrophotometer UV4100, there were almost no changes in the size and color purity between the unmodified and modified carbon black particles; electrophoretic display (EPD) experiments of the modified nano carbon black particles show that the conductivities of carbon black whose surfaces were positively or negatively charged, have been converted to very low from high. The modified nano carbon black particles have good electric field response characteristics and reversible movement at low voltage.