Complexation Of An Azo Dye By Cyclodextrins: A Potential Strategy For Water Purification

The chemistry of the host-guest complex formation has received much attention as a highly efficient approach for use to develop economical adsorbents for water purification. In the present study, the synthesis of three beta-cyclodextrin (beta-CD) inclusion complexes with the oil orange SS (DOSS) azo dye as a guest molecule and their potential applications in water purification are described. The complexes were synthesized by the coprecipitation method and characterized by Fourier transform infrared (FTIR) spectroscopy, UV-vis spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). FTIR and thermal analyses confirmed the encapsulation of OOSS dye within the hydrophobic cavity of beta-CD. The encapsulation of hydrophobic dye inside the beta-CD cavity was mainly due to the hydrophobic-hydrophobic interaction. The results showed that the stability of the OOSS dye had been improved after the complexation. The effect of three different compositions of the host-guest complexes was analyzed. The present study demonstrated that the hydrophobic dye could be removed from aqueous solution via inclusion complex formation. Thus, it can play a significant role in removing the highly toxic OOSS dye from the industrial effluent.