TY - JOUR
T1 - Enhancing DCMD vapor flux of PVDF-HFP membrane with hydrophilic silica fibers
AU - Makanjuola, Olawale
AU - Anis, Shaheen Fatima
AU - Hashaikeh, Raed
N1 - Funding Information:
The authors would like to acknowledge the support of the Core Technology Platforms team at New York University Abu Dhabi for assisting with this work. This work was supported by the NYUAD Water Research Center, funded by Tamkeen under the NYUAD Research Institute Award (project CG007).
Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/5/15
Y1 - 2021/5/15
N2 - Hydrophobicity is an important property for membranes used in direct contact membrane distillation (DCMD). The higher the hydrophobicity the better the membrane capability in preventing liquid crossover. On the other hand, membrane pore hydrophilicity enhances water vapor transport and increases membrane permeability. This tradeoff is resolved by incorporating electrospun silica fibers (SiF) as fillers in electrospun poly(vinylidenefluoride-co-hexafluropropylene) (PVDF-HFP). Composite PVDF-HFP/SiF membranes were fabricated and applied in DCMD to desalinate salt water. Various SiF loadings from 0.5 wt% to 7.0 wt% were studied. Although no hydrophobic modification was carried out on the SiF before use, they still allowed the composite membranes to maintain water contact angles above 90° due to their fibrous structure (Cassie-Baxter state). The addition of silica in fibrous form to the membrane prevented agglomeration in the composite membrane and decreased overall porosity, but resulted in higher water flux for the composite membranes compared to the neat PVDF-HFP membrane when tested for MD over a time period of 11 h with 35 g/L saline feed. Despite the hydrophilic nature of SiF, all the composite membranes maintained perfect salt rejection throughout the experiment.
AB - Hydrophobicity is an important property for membranes used in direct contact membrane distillation (DCMD). The higher the hydrophobicity the better the membrane capability in preventing liquid crossover. On the other hand, membrane pore hydrophilicity enhances water vapor transport and increases membrane permeability. This tradeoff is resolved by incorporating electrospun silica fibers (SiF) as fillers in electrospun poly(vinylidenefluoride-co-hexafluropropylene) (PVDF-HFP). Composite PVDF-HFP/SiF membranes were fabricated and applied in DCMD to desalinate salt water. Various SiF loadings from 0.5 wt% to 7.0 wt% were studied. Although no hydrophobic modification was carried out on the SiF before use, they still allowed the composite membranes to maintain water contact angles above 90° due to their fibrous structure (Cassie-Baxter state). The addition of silica in fibrous form to the membrane prevented agglomeration in the composite membrane and decreased overall porosity, but resulted in higher water flux for the composite membranes compared to the neat PVDF-HFP membrane when tested for MD over a time period of 11 h with 35 g/L saline feed. Despite the hydrophilic nature of SiF, all the composite membranes maintained perfect salt rejection throughout the experiment.
KW - Agglomeration-free
KW - Electrospun silica fibers
KW - Membrane distillation
KW - Permeability
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U2 - 10.1016/j.seppur.2021.118361
DO - 10.1016/j.seppur.2021.118361
M3 - Article
AN - SCOPUS:85100015630
SN - 1383-5866
VL - 263
JO - Separation and Purification Technology
JF - Separation and Purification Technology
M1 - 118361
ER -