Desalination by direct contact membrane distillation using mixed matrix electrospun nanofibrous membranes with carbon-based nanofillers: A strategic improvement
Robust hydrophobic and superhydrophobic mixed matrix electrospun nanofibrous membranes (MM-ENMs) have been prepared from low- and high- molecular weight polyvinylidene fluoride with either multi-walled carbon nanotubes or graphene oxide nanofillers (0.05-0.5 wt%). The polymer solutions' propert...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2021 |
| País: | España |
| Institución: | Universidad Complutense de Madrid (UCM) |
| Repositorio: | Docta Complutense |
| Idioma: | inglés |
| OAI Identifier: | oai:docta.ucm.es:20.500.14352/4731 |
| Acceso en línea: | https://hdl.handle.net/20.500.14352/4731 |
| Access Level: | acceso abierto |
| Palabra clave: | 536 Hydrophobic/hydrophilic composite membranes Air-gap Performance Layer Nanotubes Fabrication Transport Fluoride) Impact Termodinámica 2213 Termodinámica |
| Sumario: | Robust hydrophobic and superhydrophobic mixed matrix electrospun nanofibrous membranes (MM-ENMs) have been prepared from low- and high- molecular weight polyvinylidene fluoride with either multi-walled carbon nanotubes or graphene oxide nanofillers (0.05-0.5 wt%). The polymer solutions' properties, including their electrical conductivity, viscosity, and surface tension, were determined and used to guide the design of single-, dual-, and triple-layered MM-ENMs combining layers with different hydrophobic character. All MM-ENMs were subsequently prepared and characterized in terms of their morphology, hydrophobicity, mechanical properties, and direct contact membrane distillation (DCMD) performance. A thinner hydrophobic layer with a thicker hydrophilic support layer in dual-layered MM-ENMs reduced water vapor transport resistance and improved DCMD performance relative to single-layer MM-ENMs. Conversely, placing an intermediate hydrophilic layer between two hydrophobic layers in triple-layered MM-ENMs promoted water condensation (water pocket formation) and thus reduced DCMD performance. Over 10 h DCMD, the best-performing dual-layered MM-ENM allowed ultra-high permeate fluxes of up to 74.7 kg/m2 h while maintaining a stable permeate electrical conductivity of around 7.63 mu S/cm and a salt (NaCl) rejection factor of up to 99.995% when operated with a feed temperature of 80 degrees C, a permeate temperature of 20 degrees C, and a feed solution containing NaCl at a concentration of 30 g/L. |
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