دانلود رایگان مقاله جذب سطحی فولرین پلی هیدروکسی در پلی اتیلن اصلاح شده مونت موریلونیت

Abstract

The environmental behaviors and potential ecotoxicity of carbon nanomaterials, such as fullerene and its derivatives, are gaining ever-increasing concerns at present. This work attempts to develop an adsorbent for the effective removal of polyhydroxy fullerene (PHF) from aqueous solution, which was synthesized by modifying montmorillonite (Mt) with a branched polymer polyethylenimine (PEI). The adsorption results showed that the obtained adsorbent (i.e., PEI-Mt) could effectively remove PHF over a wide range of solution pH; both the electrostatic attraction and hydrogen-bond interaction between PHF and PEI-Mt contributed to the strong adsorption. Decreasing solution pH and rising PEI loading amount on Mt could both increase the adsorption amounts of PHF on PEI-Mt. The adsorption isotherms could be well fitted with the Langmuir model, and the calculated maximum adsorption value of PHF on 10%PEI-Mt reached ~213 mg/g, much higher than that on the original Mt (~16 mg/g). The adsorbents after PHF adsorption were further characterized using Fourier transform infrared spectroscopy, X-ray diffraction, and transmission electron microscopy. The results suggested that the adsorbed PHF primarily existed on the outer surfaces of PEI-Mt. This work showed that PEI-Mt can be a potentially efficient adsorbent for the removal of PHF from aqueous solution.

4. Conclusion

In summary, the modification of Mt with a branched polymer PEI developed a novel adsorbent, PEI-Mt, for the remediation of the wastewater containing PHF. The adsorption experiments demonstrated that PEIMt showed superior adsorption capacity for PHF over a wide variety of solution pH range, which could be attributed to the combined contributions of the electrostatic attraction and the hydrogen-bond interaction between PHF and PEI-Mt. The adsorption amounts of PHF on PEI-Mt increased with rising PEI loading amount on Mt and with decreasing solution pH. The adsorption equilibrium data of PHF on all the absorbents were well fitted with the Langmuir model, and the calculated maximum adsorption amount of PHF on 10%PEI-Mt reached ~ 213 mg/g, much higher than that on the original Mt (~16 mg/g). In addition, the XRD and TEM results revealed that the adsorbed PHF mainly existed on the external surfaces of PEI-Mt. This work indicated that PEI-Mt had high af- finity toward PHF and could be applied as a potentially desirable adsorbent for the removal of PHF from aqueous solution.