Understanding membrane fouling by oil-in-water emulsion via experiments and molecular dynamics simulations

The ferrofluid-in-water emulsion has been produced and studied. The microstructure formation in a flat layer of such emulsion under the action of in-plane rotating magnetic field has been observed. Several microstructure types have been found such as chain-like aggregates, disc-like clusters, branching and space-occupying structures. The time evolution of the formation process has been analysed. The revealed microstructures have been computationally investigated by molecular dynamics simulations. The microstructure dynamics in ferrofluid emulsions manifests itself in macroscopic mechanical effects. We analysed the appearance of macroscopic torque on a ferrofluid emulsion sample in a rotating magnetic field. The value of the torque has been measured as a function of magnetic field strength and frequency.

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Computational investigation of a switchable emulsion stabilized by the mixture of a surfactant and tertiary amine

Physical Chemistry Chemical Physics ◽

10.1039/d0cp05686c ◽

2021 ◽

Vol 23 (1) ◽

pp. 368-377

Author(s):

Yue Wang ◽

Hui Yan ◽

Xiujuan Zhong ◽

Shiling Yuan

Keyword(s):

Molecular Dynamics ◽

Molecular Dynamics Simulations ◽

Sodium Oleate ◽

Tertiary Amine ◽

Computational Investigation ◽

Oil In Water ◽

Dynamics Simulations

Molecular dynamics simulations were performed to investigate the CO2-responsiveness of an oil-in-water (O/W) emulsion stabilized by sodium oleate (NaOA) with a tertiary amine additive, named pentamethyl diethylenetriamine (PMA).

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A Model for Lubrication by Oil-in-Water Emulsions

Journal of Tribology ◽

10.1115/1.4000274 ◽

2009 ◽

Vol 132 (1) ◽

Cited By ~ 9

Author(s):

Sy-Wei Lo ◽

Tzu-Chun Yang ◽

Yong-An Cian ◽

Kuo-Cheng Huang

Keyword(s):

Film Thickness ◽

Volume Fraction ◽

Ph Value ◽

Oil Viscosity ◽

Water Emulsion ◽

Oil In Water ◽

Critical Volume Fraction ◽

Oil Concentration ◽

Dynamics Simulations ◽

Oil In Water Emulsion

A model for oil-in-water emulsion has been developed in this paper. A group of viscosity coefficients transiting smoothly and incessantly from the thick film region to the thin film region is defined. The contributions from disperse and continuous phases to the total lubricant pressure and pressure gradient are functions of the oil concentration and the film thickness. The parameters used in these functions are determined by a series of computational fluid dynamics simulations. The onset of inversion and the viscosity after inversion are also investigated. It is found that the critical volume fraction of oil in the inception of inversion is dependent on the oil viscosity and a factor regarding the combined effects from the emulsifier, pH value, droplet size, and the shear rate. A series of simulations using the proposed model has been carried out and compared with the experimental results, such as the film thickness and the extension of oil pool for various rolling speeds and supply oil concentrations. The numerical outputs are basically in agreement with the experiments.

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Membrane surface properties and their effects on real waste oil-in-water emulsion ultrafiltration

Water SA ◽

10.17159/wsa/2019.v45.i3.6733 ◽

2019 ◽

Vol 45 (3 July) ◽

Cited By ~ 1

Author(s):

Marjana Simonič

Keyword(s):

Surface Properties ◽

Membrane Fouling ◽

Membrane Surface ◽

Cross Flow ◽

Influential Factors ◽

Permeate Flux ◽

Chemical Cleaning ◽

Water Emulsion ◽

Oil In Water ◽

Oil In Water Emulsion

Membrane surface properties and their effect on the efficiency of ultrafiltration (UF) of real waste oily emulsions was studied. Experiments were performed in cross-flow operation at total recycle condition in a lab-scale system. The ceramic UF membrane in the tubular type module was employed. During the experiments permeate flux was measured. The most important influential factors, such as temperature, TMP, and pH, were considered during the experiments. Zeta potential was measured in order to explain the phenomena on the membrane surface. The isoelectric point of the fouled membrane was shifted to the alkaline range. COD removal efficiency reached 89%. Gas chromatography measurements were performed in order to determine the composition of waste emulsions. SEM micrographs showed the formation of calcite on the membrane, which contributed to membrane fouling. Chemical cleaning was examined using alkaline and acid solutions, and a cleaning strategy was determined.

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Antifouling enhancement of polyacrylonitrile-based membrane grafted with poly(sulfobetaine methacrylate) layers

Journal of Polymer Engineering ◽

10.1515/polyeng-2021-0112 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Jianlong Hu ◽

Xuanren Zhu ◽

Deqiong Xie ◽

Xianya Peng ◽

Meng Zhu ◽

...

Keyword(s):

Membrane Fouling ◽

Separation Efficiency ◽

Membrane Surface ◽

Surface Grafting ◽

Water Emulsion ◽

Oil In Water ◽

Oil Adsorption ◽

Grafting Copolymerization ◽

Oil In Water Emulsion ◽

Oil Fouling

Abstract In this work, zwitterionic polyacrylonitrile (PAN)-based membranes were synthesized via surface grafting strategy for improving the antifouling properties. The copolymer membrane consisting of PAN and poly(hydroxyethyl methacrylate) segments, was cast via nonsolvent induced phase separation, and then treated with acryloyl chloride to tether with carbon-carbon double bonds. Zwitterionic poly(sulfobetaine methacrylate) (PSBMA) layers were grafted onto membrane surface via concerted reactions of radical grafting copolymerization and quaternization with 2-(dimethylamino)ethyl methacrylate) and 1, 3-propanesultone (1, 3-PS) as the monomers. The grafting degree (GD) of PSBMA layers increases with the incremental content of monomers, leading to the enhancement in membranes surface hydrophilicity. The permeation experiments show that the flux of the zwitterionic membrane increases and then decreases with the increasing GD value, because of the surface coverage of PSBMA layers. The zwitterionic membrane has excellent separation efficiency for oil-in-water emulsion, with the rejection of a higher value than 99%. The irreversible membrane fouling caused by oil adsorption has been suppressed, as proved by the cycle-filtration tests. These outcomes confirm that oil-fouling resistances of membranes are improved obviously by the surface grafting of zwitterionic PSBMA layers.

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