Core-shell graphene oxide-polymer hollow fibers as water filters with enhanced performance and selectivity
Journal article, 2021
Commercial hollow fiber filters for micro- and ultrafiltration are based on size exclusion and do not allow the removal of small molecules such as antibiotics. Here, we demonstrate that a graphene oxide (GO) layer can be firmly immobilized either inside or outside polyethersulfone-polyvinylpyrrolidone hollow fiber (Versatile PES (R), hereafter PES) modules and that the resulting core-shell fibers inherits the microfiltration ability of the pristine PES fibers and the adsorption selectivity of GO. GO nanosheets were deposited on the fiber surface by filtration of a GO suspension through a PES cartridge (cut-off 0.1-0.2 mu m), then fixed by thermal annealing at 80 degrees C, rendering the GO coating stably fixed and unsoluble. The filtration cut-off, retention selectivity and efficiency of the resulting inner and outer modified hollow fibers (HF-GO) were tested by performing filtration on water and bovine plasma spiked with bovine serum albumin (BSA, 66 kDa, approximate to 15 nm size), monodisperse polystyrene nanoparticles (52 nm and 303 nm sizes), with two quinolonic antibiotics (ciprofloxacin and ofloxacin) and rhodamine B (RhB). These tests showed that the microfiltration capability of PES was retained by HF-GO, and in addition the GO coating can capture the molecular contaminants while letting through BSA and smaller polystyrene nanoparticles. Combined XRD, molecular modelling and adsorption experiments show that the separation mechanism does not rely only on physical size exclusion, but involves intercalation of solute molecules between the GO layers.
Author
Alessandro Kovtun
National Research Council of Italy (CNR)
Antonio Bianchi
National Research Council of Italy (CNR)
Massimo Zambianchi
National Research Council of Italy (CNR)
Cristian Bettini
National Research Council of Italy (CNR)
Franco Corticelli
National Research Council of Italy (CNR)
Giampiero Ruani
National Research Council of Italy (CNR)
Letizia Bocchi
Medica
Francesco Stante
Stante Laboratories
Massimo Gazzano
National Research Council of Italy (CNR)
Tainah Dorina Marforio
University of Bologna
Matteo Calvaresi
University of Bologna
Matteo Minelli
University of Bologna
Maria Luisa Navacchia
National Research Council of Italy (CNR)
Vincenzo Palermo
Chalmers, Industrial and Materials Science, Materials and manufacture
National Research Council of Italy (CNR)
Manuela Melucci
National Research Council of Italy (CNR)
Faraday Discussions
1359-6640 (ISSN) 1364-5498 (eISSN)
Vol. 227 274-290Subject Categories (SSIF 2011)
Polymer Technologies
Materials Chemistry
Other Chemistry Topics
DOI
10.1039/c9fd00117d
PubMed
33300505