Facile Fabrication of Multi-Structured SiO₂@PVDF-HFP Nanofibrous Membranes for Enhanced Copper Ions Adsorption.

Haohong Pi,Rui Wang,Xiuqin Zhang,Baona Ren,Jing Wu

doi:10.3390/polym10121385

Abstract

The low-cost, heavy metal ion (Cu(II)) adsorptive multi-structured nanofibrous membranes of silicon oxide naonoparticles in-situ anchored polyvinylidene fluoride-hexafluoropropylene (SiO2@PVDF-HFP) fibers were fabricated by the facile electrospinning technique combined with sol–gel strategy. To explore the benefits of the structure-related Cu(II) adsorption capacity, the fiber diameters of SiO2@PVDF-HFP nanofibrous membranes were changed which also resulted in the change of their porosity. Taking advantage of the constructed multi-structures and efficient fiber morphology regulation which not only changed the PVDF-HFP nanofibrous membrane from hydrophobic to superhydrophilic but also increased the porosity of the membrane, the SiO2@PVDF-HFP nanofibrous membrane with a smaller diameter and a larger porosity exhibits higher Cu(II) adsorption capacity. The adsorption amount was approximate to 21.9 mg per gram of the membrane, which was higher than that of membranes with larger fiber diameter (smaller porosity) and the smooth one. Furthermore, the model isotherms of Freundlich and Langmuir, as well as the kinetic models of pseudo-first-order and pseudo-second-order were preferred to analyze the adsorption equilibrium data. The Freundlich model and the pseudo-first-order were well fitted to the adsorption experimental data. It not only uncovers the structure-related-property of multi-structured nanofibrous membranes, but also provides an efficient and facile way to design heavy metal ion adsorption materials.

Highlights

Heavy-metal ions are a severe environmental problem in that organic and toxic waste in water poses a major health risk to humankind, and destroys the circulation of the ecological environment [1,2]
Polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) was used as the raw materials to fabricate the nanoparticle anchored on nanofiber multi-structured membranes
PVDF-HFP fibrous membrane was immersed in the stirring alcohol, and TEOS was added dropwise at the same time

Summary

Introduction

Heavy-metal ions are a severe environmental problem in that organic and toxic waste in water poses a major health risk to humankind, and destroys the circulation of the ecological environment [1,2]. Cognizant of its hazards, researchers have developed a great deal of techniques to transfer and adsorb heavy metal ions in aqueous solution, such as chemical treatments [3,4,5,6,7,8], biochemical processes [9,10], physicochemical treatments [11,12], et al Among these, adsorption technology was considered as the simple operation and much more efficient method for removal of heavy metal ions [13,14,15]. There is an additional cost to recover the powders that had been used to remove heavy ions in water.

Methods

Results

Conclusion