Use of PVA/α-MnO2-stearic acid nanocomposite films prepared by sonochemical method as a potential sorbent for adsorption of Cd (II) ion from aqueous solution

Alpha manganese dioxide (alpha-MnO2) nanorods have been covalently functionalized with stearic acid by solvothermal method. The alpha-MnO2-stearic acid nanorods were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy and transmission electron microscopy. The amount of stearic acid grafted onto alpha-MnO2 surface was determined about 41 wt % by thermogravimetric analysis. The alpha-MnO2-stearic acid nanorods was used as nanofiller for the preparation of poly(vinyl alcohol) (PVA) nanocomposites (NCs). The NCs with 1, 3, and 5 wt% of nanofiller were prepared through ultrasound assisted technique as an economical, fast, eco-friendly, and effective method. The PVA/alpha-MnO2-stearic acid NCs were characterized by different techniques. The results showed that with increasing the alpha-MnO2-stearic acid content, the thermal stability and tensile properties were improved. Besides, the NC 5 wt% was used as adsorbent for sorption of Cd (II) ion. The adsorption efficiency of NC 5 wt% in different initial concentrations of Cd (II) ion (20-100 mg L-1) was 58-95%. All the isotherm data were well fitted by both Langmuir and Freundlich equations. The adsorption kinetics study demonstrated that pseudo-second-order model was the best fit with the experimental data. The results indicated that prepared NCs are promising adsorbents for the removal of Cd (II) ion from the aqueous solution. (C) 2017 Elsevier B.V. All rights reserved.