Preparation and characterization of poly(acrylic acid-co-acrylamide)/montmorillonite composite and its application for methylene blue adsorption

Abstract

A series of poly(acrylic acid-co-acrylamide)/montmorillonite composite (poly(AA-co-AM)/MMT) was prepared by radical polymerization. The composite was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), energy dispersive X-ray (EDX) and X-ray diffraction (XRD). Batch adsorption experiments of methylene blue (MB) from aqueous solutions were carried out with poly(AA-co-AM)/MMT composite. The effects of montmorillonite (MMT) content, initial pH of MB solutions, adsorption temperature, and ionic strength on the adsorption were investigated. Furthermore, the adsorption kinetics and isotherms were studied by analyzing the effect of adsorption time and initial MB concentration on the adsorption capacity. The results indicated that the addition of a small amount of MMT could improve the adsorption capacity of the poly(AA-co-AM). The maximum adsorption capacity of poly (AA-co-AM)/MMT (2%) composite was 1964.1 mg g−1. The adsorption kinetics were in good agreement with the pseudo-second-order equation, and the adsorption isotherms were better fitted for the Langmuir equation. In addition, desorption studies show that the composites have good regenerative properties. The experimental results show that the poly(AA-co-AM)/MMT can be used as promising adsorbent for the removal of MB from wastewater.