title: A new nano-engineered hierarchical membrane for concurrent removal of surfactant and oil from oil-in-water nanoemulsion.
abstract: Surfactant stabilized oil-in-water nanoemulsions pose a severe threat to both the environment and human health. Recent development of membrane filtration technology has enabled efficient oil removal from oil/water nanoemulsion, however, the concurrent removal of surfactant and oil remains unsolved because the existing filtration membranes still suffer from low surfactant removal rate and serious surfactant-induced fouling issue. In this study, to realize the concurrent removal of surfactant and oil from nanoemulsion, a novel hierarchically-structured membrane is designed with a nanostructured selective layer on top of a microstructured support layer. The physical and chemical properties of the overall membrane, including wettability, surface roughness, electric charge, thickness and structures, are delicately tailored through a nano-engineered fabrication process, that is, graphene oxide (GO) nanosheet assisted phase inversion coupled with surface functionalization. Compared with the membrane fabricated by conventional phase inversion, this novel membrane has four times higher water flux, significantly higher rejections of both oil (~99.9%) and surfactant (as high as 93.5%), and two thirds lower fouling ratio when treating surfactant stabilized oil-in-water nanoemulsion. Due to its excellent performances and facile fabrication process, this nano-engineered membrane is expected to have wide practical applications in the oil/water separation fields of environmental protection and water purification.
authors.affiliation: Energy Research Institute @ NTU, Interdisciplinary Graduate School, Nanyang Technological University, 639798, Singapore.
authors.forename: Detao
authors.initials: D
authors.lastname: Qin
authors.affiliation: Qatar Environment and Energy Research Institute (QEERI), Hamad bin Khalifa University (HBKU), Qatar Foundation, PO Box 5825, Doha, Qatar.
authors.forename: Zhaoyang
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Energy Research Institute @ NTU, Nanyang Technological University, 639798, Singapore.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Bai
authors.affiliation: School of Civil and Environmental Engineering, Nanyang Technological University, 639798, Singapore.
authors.forename: Darren Delai
authors.initials: DD
authors.lastname: Sun
authors.affiliation: School of Civil and Environmental Engineering, Nanyang Technological University, 639798, Singapore.
authors.forename: Xiaoxiao
authors.initials: X
authors.lastname: Song
mesh_terms: D004655:Emulsions; D006108:Graphite; D008567:Membranes, Artificial; D049329:Nanostructures; D000069463:Olive Oil / Q000302:isolation & purification*; D010087:Oxides; D010938:Plant Oils / Q000302:isolation & purification*; D000074242:Sunflower Oil; D013501:Surface-Active Agents / Q000302:isolation & purification*; D014867:Water / Q000737:chemistry*; D018508:Water Purification / Q000295:instrumentation; D017155:Wettability
chemical_list: D004655:Emulsions; D008567:Membranes, Artificial; D000069463:Olive Oil; D010087:Oxides; D010938:Plant Oils; D000074242:Sunflower Oil; D013501:Surface-Active Agents; D014867:Water; D006108:Graphite