TY - JOUR
T1 - PVDF membranes containing reduced graphene oxide
T2 - Effect of degree of reduction on membrane distillation performance
AU - Abdel-Karim, Ahmed
AU - Luque-Alled, Jose Miguel
AU - Leaper, Sebastian
AU - Alberto, Monica
AU - Fan, Xiaolei
AU - Vijayaraghavan, Aravind
AU - Gad-Allah, Tarek A.
AU - El-Kalliny, Amer S.
AU - Szekely, Gyorgy
AU - Ahmed, Sayed I.A.
AU - Holmes, Stuart M.
AU - Gorgojo, Patricia
N1 - Funding Information:
The authors would like to acknowledge EPSRC for funding this work (grant number EP/K016946/1 ). A. Abdel-Karim would like to thank the Ministry of Higher Education of Egypt and the Newton-Mosharafa Fund.
Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2019/2/15
Y1 - 2019/2/15
N2 - Hydrophobic polyvinylidene fluoride (PVDF) membranes have been successfully used in membrane distillation (MD) for desalination applications; however, there is still room for performance enhancements both regarding water flux and salt rejection. In this work, reduced graphene oxide (rGO) nanoplatelets with different degrees of reduction (36%, 58%, 65 and 69% removal of oxygen, as characterized by XPS) were incorporated as fillers in PVDF matrices in order to evaluate the effect of the oxygen content of the fillers in the MD performance. UV–Vis and Raman spectroscopies were also used to characterize the fabricated rGO. Changes in morphology of the prepared mixed matrix membranes (MMMs) were assessed via scanning electron microscopy (SEM) and were related to the increased hydrophilicity and viscosity of the casting solutions when fillers were added. MMMs containing 0.5 wt% rGO with an optimum degree of reduction of 58% exhibited an improved MD performance, with fluxes of ~7.0 L m−2 h−1 (LMH), representing an enhancement of ~169% in comparison with the plain PVDF membrane, without compromising salt rejection (>99.99%). Continuous testing for up to 96 h showed a stable performance of the developed MMMs, without compromising the quality of the permeate.
AB - Hydrophobic polyvinylidene fluoride (PVDF) membranes have been successfully used in membrane distillation (MD) for desalination applications; however, there is still room for performance enhancements both regarding water flux and salt rejection. In this work, reduced graphene oxide (rGO) nanoplatelets with different degrees of reduction (36%, 58%, 65 and 69% removal of oxygen, as characterized by XPS) were incorporated as fillers in PVDF matrices in order to evaluate the effect of the oxygen content of the fillers in the MD performance. UV–Vis and Raman spectroscopies were also used to characterize the fabricated rGO. Changes in morphology of the prepared mixed matrix membranes (MMMs) were assessed via scanning electron microscopy (SEM) and were related to the increased hydrophilicity and viscosity of the casting solutions when fillers were added. MMMs containing 0.5 wt% rGO with an optimum degree of reduction of 58% exhibited an improved MD performance, with fluxes of ~7.0 L m−2 h−1 (LMH), representing an enhancement of ~169% in comparison with the plain PVDF membrane, without compromising salt rejection (>99.99%). Continuous testing for up to 96 h showed a stable performance of the developed MMMs, without compromising the quality of the permeate.
KW - Air gap membrane distillation (AGMD)
KW - Desalination
KW - Hydrophobic polyvinylidene fluoride (PVDF)
KW - Mixed matrix membranes (MMMs)
KW - Reduced graphene oxide (rGO)
UR - http://www.scopus.com/inward/record.url?scp=85056892683&partnerID=8YFLogxK
U2 - 10.1016/j.desal.2018.11.014
DO - 10.1016/j.desal.2018.11.014
M3 - Article
AN - SCOPUS:85056892683
SN - 0011-9164
VL - 452
SP - 196
EP - 207
JO - Desalination
JF - Desalination
ER -