Fast removal of cationic dyes using pH-sensitive Fe₃O₄/poly(methacrylic acid) nanocomposite particles

Abstract

In this work, the pH-sensitive magnetic Fe₃O₄/polymethacrylic acid nanocomposite particles were synthesized by a new one-step method and used as adsorbents for the removal of two cationic dyes from aqueous solution. The resulting product was characterized using Fourier transform infrared spectra, transmission electron microscopy (TEM), thermogravimetric analysis, and vibrating sample magnetometer. Particles size distribution of product and its pH responsivity was investigated by dynamic light scattering. Adsorption performance of the magnetic adsorbent was tested with removal of methylene blue and maxilon red GRL from aqueous solution. The effects of solution pH value, adsorption time and initial dye concentration were investigated. The adsorption behavior fits well with the Langmuir rather than the Freundlich model. The results reveal that the adsorbent has ability to remove dyes rapidly within a few minutes due to the absence of the internal diffusion resistance. Moreover, the synthesized adsorbent has good reusability.

Keywords:

• Fe₃O₄ nanoparticle
• Surface modification
• Polymethacrylic acid
• Cationic dyes
• pH sensitive
• Adsorption

Acknowledgments

The authors acknowledge the Department of Textile Engineering in the Amirkabir University of Technology for supporting this work.