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

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.

Advanced Polymeric Nanocomposite Membranes for Water and Wastewater Treatment: A Comprehensive Review

“…Silica NPs have been incorporated within the polymer matrix or anchored on the surfaces of electrospun polymeric fibrous membranes. Pi et al impregnated silica NPs on electrospun poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) to form superhydrophilic multistructured nanofibrous membranes for the removal of Cu(II) ion, which resulted in an adsorption capacity of 21.9 [ 165 ]. A Freundlich adsorption isotherm and a pseudo-first-order kinetic model was best fit for the experimental data.…”

Recent Progress on Nanomaterial-Based Membranes for Water Treatment

“…Silica@Polyvinylidene fluoride-hexafluoropropylene Cu(II) 21.9 [210] Polyacrylonitrile/Chitosan Cr(III) 116.5 [211] MgAl-EDTH-LDH@Polyacrylonitrile Cu(II) 120.77 [212] Polyvinyl alcohol/Silica Mn(II), Ni(II) 234.7, 229.9 [213] Polyvinylpyrrolidone/Silica Hg(II) 852 [214] Chitosan…”

Recovery of Extracellular Polymeric Substances from Excess Sludge Using High-Flux Electrospun Nanofiber Membranes

“…Thus, ENMs have been examined for their application in the removal of heavy metals [ 55 , 56 ]. For example, metal–organic frameworks were enmeshed in PVDF and polyacrylonitrile electrospun nanofibers to produce nanofibrous membranes for the treatment of Pb 2+ solutions [ 57 ], while PVDF nanofibrous membranes hybridized with silicon oxide nanoparticles exhibited a Cu 2+ adsorption of ~21.9 mg/g [ 58 ]. In addition, the incorporation of carbohydrate polymers, such as chitosan, cellulose, alginate, pullulan, starch, and hyaluronic acid into nanofibrous structures via the electrospinning approach has also been proven effective in the adsorption of heavy metals [ 49 , 59 ].…”