Formation and characterization of superhydrophilic carbon black via layer-by-layer electro-assembly

The superhydrophilic carbon black, CB, was prepared by layer-by-layer electro-assembly, LBLEA. Experimentally, the positive charged poly(diallyldimethylammonium chloride), PDDA, was used as a layer supporter to form the CB/PDDA multilayer films. Wetting results shown that the CB surface at 4 kV and EFreduction condition can be in superhydrophilicity due to this surface sensitively responded to the EF-reduction condition and ignored the EF-enhancement condition. As a support, the positive charged PDDA surface under the same conditions shown variety on the contrary due to it sensitively to the EF-enhancement condition. This work suggested that the voltage increase together with the EF-reduction can move the hydrophilic CeO groups from the bulk to the CB surface, while the voltage increase together with the EF-enhancement can move the hydrophobic CH2 groups from the bulk to the PDDA surface.