دانلود رایگان مقاله جذب دو ظرفیتی یون فلزات سنگین توسط اکسید کیتوزان / پلی اتیلن

ABSTRACT

In this study, chitosan/poly (ethylene oxide) nanofibres were fabricated at different chitosan:PEO weight ratio by electrospinning process. The effects of chitosan/PEO composition onto adsorption capability for Cu(II), Zn(II) and Pb(II) ions were studied. Formation of beadless fibres were achieved at 60:40 chitosan:PEO ratio. Average fiber diameter, maximum tensile strength and the specific surface area of the beadless fibres were found to be 115 ± 31 nm, 1.58 MPa and 218 m2/g, respectively. Chitosan/PEO composition that produced beadless fibres tend to possess higher hydrophilicity and maximum specific surface area. These characteristics lead the beadless fibres to the maximum adsorption capability. Adsorption equilibrium data were analysed by Langmuir and Freundlich isotherm. Freundlich isotherm showed the better fit with the experimental data and proved the existence of the monolayer adsorption conditions. The maximum adsorption capacity of the beadless fibres for Cu(II), Zn(II) and Pb(II) ions were found to be 120, 117 and 108 mg g−1, respectively.

4. Conclusion

In this study, chitosan/PEO nanofibrous membrane having no beads, mesopores, and high specific surface area was successfully synthesized by electrospinning process. The formation of hydrogen bonding between the molecules of chitosan and PEO were substantiated by FTIR, and XRD analysis. Beadless fibres tend to show lowest contact angle and highest specific surface area, which are advantageous for the adsorption process. Based on the kinetic study, pseudo second order kinetic model was best suited with the experimental data.Whereas the comparative equilibrium isotherm experiments shows that, Langmuir isotherm can better describe the adsorption of metal ion. The maximum adsorption capacity for Cu(II), Zn(II) and Pb(II) ions were found to be 120, 117 and 108 mg g−1 respectively. The physical adsorption nature was proved by Freundlich isotherm constant value. Moreover,the beadless nanofibres can be reused without having no significant loss of adsorption capability.