Electrospun functionalized polyacrylonitrile–chitosan Bi-layer membranes for water filtration applications

Abstract

Water scarcity has become a global systemic risk, prompting the development of more efficient filtration technologies. Recently, increasing attention has been given to low cost membrane materials such as polyacrylonitrile (PAN) nanofibers for water filtration. In this study, electrospun PAN nanofibrous membranes were functionalized with zinc oxide (ZnO) nanoparticles and coated with a layer of electrospun chitosan (Cs), in order to improve the mechanical properties, and anti-bacterial and water filtration performance of the membranes. Morphological analysis revealed that the PAN/ZnO-Cs membranes featured a structural hierarchy comprising a layer of highly porous nanofibrous PAN membranes and a less fibrous and thinner layer of a Cs coating. Addition of the Cs layer increases the tensile strength and elastic modulus of the membranes. Results acquired from a water permeability test indicated that the bi-layer membranes possessed adequate transport properties for typical membrane applications. Furthermore, the additional Cs layer and ZnO nanoparticles significantly improved the heavy metal ion adsorption performance of the PAN membranes. Moreover, the efficiency of the PAN/ ZnO-Cs membrane for bacteria filtration has a log reduction value 2 orders of magnitude higher than PAN membranes, while the efficiency of these membranes for antibacterial action (i.e. in terms of log reduction value) is 6 orders of magnitude higher than PAN membranes. These results indicate the PAN/ ZnO-Cs membranes are structurally more stable than PAN membranes, better at bacteria removal during the filtration process and better at self-cleaning (i.e. membrane biofouling resistance) than PAN membranes, signifying the potential of these membranes for water filtration applications. Fig. 7 Bacteria filtration performance of electrospun membranes. Error bars represented AE1SD from triplicate. 53890 | RSC Adv., 2016, 6, 53882-53893 This journal is

Core–sheath nanofibrous membranes based on poly(acrylonitrile‐butadiene‐styrene), polyacrylonitrile, and zinc oxide nanoparticles for photoreduction of Cr(VI) ions in aqueous solutions

“…26,35,38,[41][42][43][46][47][48] In this work, a solution containing 6 wt % of PAN was electrospun leading to highly homogeneous fibrous membranes with D f equals to 400 nm with a diameter distribution from 250 to 750 nm ( Figure 3). 26,35,38,[41][42][43][46][47][48] In this work, a solution containing 6 wt % of PAN was electrospun leading to highly homogeneous fibrous membranes with D f equals to 400 nm with a diameter distribution from 250 to 750 nm ( Figure 3).…”

“…[5][6][7][8][9][10] Regarding the inorganic nanoparticles, the scientific community has taken advantage of the photocatalytic activity of zinc oxide (ZnO) to develop materials with antimicrobial activity and dye degradation. 42 Mikal et al also designed PAN/ZnO nanoparticles membranes by electrospinning and explored the effect of fibers composition and test conditions on lead ions removal. More importantly, ZnO is considered as a safe Additional Supporting Information may be found in the online version of this article.…”

Enhancement of heavy metal ion adsorption using electrospun polyacrylonitrile nanofibers loaded with ZnO nanoparticles

“…The addition of small amounts of metal oxide nanoparticles into electrospun polymeric nanofibers improves their adsorption performance . Zhang et al .…”

“…indicated that the introduction of 4 wt% ZnO nanoparticles into the surface of graphene nanosheets can significantly enhance the adsorption of Ni(II) to a maximum of 66.7 mg/g at room temperature. In a similar study by Makaremi et al ,. the addition of 5 w/w% ZnO nanoparticles into electrospun PAN membranes improved the adsorption efficiency of Cr(III) ions from 4% to 34%.…”

“…More specifically, we investigated the adsorption efficiency of four different electrospun PAN/ZnO [0.5, 1.0, 2.0, and 5.0 wt%] composite nanofibers in the removal of Pb(II) and Cd(II) from aqueous solutions. This choice of low ZnO contents was motivated by many prior studies that showed good adsorption performance of other heavy metal ions when using low weight percentage of ZnO . Further, the high concentrations of ZnO may lead to more agglomeration of nanoparticles in the structure of the nanofibers due to the nonuniform dispersion of ZnO.…”