UV-Visible Spectrometric Study and Micellar Enhanced Ultrafiltration of Alizarin Red S Dye

Abstract

Ultraviolet spectrometric study of alizarin red S (ARS) showed the substantial change in dye spectra by cationic CTAB as compared to anionic SDS and nonionic TX-100 surfactant. High spectral change by CTAB confirms the anionic nature of ARS dye and thus ARS-CTAB complex formation takes place due to electrostatic force of attraction. A little spectral change by SDS is the result of similarly charged repulsive forces that overcome weak hydrophobic-hydrophobic interaction between dye and surfactant micelles. TX-100 exhibited moderate spectral effect responsive to weak hydrophobic-hydrophobic interaction alone. MEUF study of ARS dye justified the spectral changes and dye rejection percentage (R) decreases in the following order: cationic > nonionic > anionic surfactant. Permeate flux (J) slightly decreases in presence of CTAB and it remains virtually constant for both SDS and TX-100. Addition of copper salt (i.e., CuCl₂) in dye-CTAB complex solution, favors rejection (%) removing dye and copper simultaneously via micellar enhanced ultrafiltration.

Keywords:

• Alizarin red S
• micellar enhanced ultrafiltration
• permeate flux
• rejection percentage
• surfactant

Acknowledgements

The authors acknowledged the Department of Chemistry, Quaid-i-Azam University-Islamabad for funding and laboratory facilities.

Notes

^a ARS dye concentration in permeate solution.

^b Concentration of copper in permeate solution.

^c Equation (2) used for MEUF to determine permeate flux (J) is not applicable in paper filtration.