Adsorptive removal of Acid Red 1 from aqueous solution with surfactant modified titanate nanotubes

TNT was prepared via a hydrothermal method and subsequently washed with a 10(-4) N HCl aqueous solution. The prepared TNT was then mediated with a quaternary amine, hexadecyltrimethylammonium (HDTMA) chloride, through the cation exchange process. The revolution of both the surface area and pore structure of TNT was characterized based on the classical and fractal analyses of the nitrogen adsorption-desorption isotherms as well as the X-ray diffraction (XRD) patterns. The change in surface characteristics of TNT was identified with the Fourier transform infrared (FTIR) patterns and zeta potential plots. The adsorption isotherms of an acid dye, Acid Red 1 (AR1), on the HDTMA-modified TNT (HMTNT) samples were then measured to understand the effects of surfactant modified process on the adsorption properties of TNT. It was found that HDTMA-mediated process might decrease the BET surface area, pore size, pore volume, and surface fractal dimension of TNT. On the other hand, the hydrophobic bonding by conglomeration of large C-16 alkyl groups associated with HDTMA could render a positive charge development on the surface of TNT. The effects of the alteration of the surface characteristics of TNT on its adsorption selectivity for acid dye were discussed.