Rhodamine 6G assisted adsorption of metanil yellow over succinamic acid functionalized MCM-41

The adsorption properties of succinamic acid functionalised MCM-41 (SA-MCM-41) towards dyes aqueous solution, such as rhodamine 6G (R6G), methylene blue (MB) and metanil yellow (MY), were studied. SA-MCM-41 was synthesised using a three step synthesis strategy, starting with the preparation of MCM-41 through a sol-gel methodology. Succinamic acid functionality was introduced through a ring opening reaction of succinic anhydride (SA) over the propyl amine functionality of A-MCM-41 in presence of trimethylamine. The materials at each synthesis step were characterised by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, N-2 adsorption-desorption isotherms, Fourier transform infrared spectroscopy, and Si-29 and C-13 nuclear magnetic resonance spectroscopies. SA-MCM-41 exhibited good adsorption capacity towards R6G and MB but poor adsorption for MY from the individual dye solutions. The competitive adsorption from binary and ternary dye mixtures showed that SA-MCM-41 can remove MY effectively in the presence of R6G. The adsorption behaviour of R6G and MY over SA-MCM-41 from binary and ternary mixtures highlight the possibility of multilayer adsorption. The MY removal efficiency of pristine MCM-41 from R6G-MY binary mixture was also tested. (C) 2016 Elsevier Ltd. All rights reserved.