L-histidine-functionalized carbon black pigment with zwitterionic property: Preparation, characterization and application

Abstract

In this paper, anl-histidine-functionalized carbon black (CB–HIS) with zwitterionic property was fabricated by covalently binding l-histidine to oxidized carbon black under the action of a crosslinker. The oxidized carbon black was prepared by two-step oxidation using ozone and hydrogen peroxide as oxidants respectively. Scanning electron microscopic techniques (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Thermogravimetric analysis (TGA) and Zeta potential were employed to characterize the composition, structure and properties of the CB-HIS as well as the intermediates. The results showed that the l-Histidine was successfully grafted on the pretreated CB through C–NH of the imidazole ring and remained the branched amino groups and carboxyl groups. The Zeta potential estimated that the isoelectric point of CB-HIS was about 3.78. The CB-HIS pigment was applied to dye wool fabrics through exhaust dyeing process. The K/S, L*a*b* values and the color appearance of dyed wool fabrics showed that the CB-HIS-dyed wool fabrics had darker black and better fastness properties than the pristine CB-dyed wool fabrics. This work provides a versatile route to prepare functionalized carbon blacks by autonomously selecting amino acids.