1
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Li X, Zhang G, Hu C, Lan H, Liu H. Demulsification with simultaneous water purification by coupling filtration and enhanced oil droplet coalescence at anode interface in an electrochemical reactor. J Environ Sci (China) 2024; 146:118-126. [PMID: 38969440 DOI: 10.1016/j.jes.2023.06.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 06/03/2023] [Accepted: 06/10/2023] [Indexed: 07/07/2024]
Abstract
With the increasing demand of recycling disposal of industrial wastewater, oil-in-water (O/W) emulsion has been paid much attention in recent years owing to its high oil content. However, due to the presence of surfactant and salt, the emulsion was usually stable with complex physicochemical interfacial properties leading to increased processing difficulty. Herein, a novel flow-through electrode-based demulsification reactor (FEDR) was well designed for the treatment of saline O/W emulsion. In contrast to 53.7% for electrical demulsification only and 80.3% for filtration only, the COD removal efficiency increased to 92.8% under FEDR system. Moreover, the pore size of electrode and the applied voltage were two key factors that governed the FEDR demulsification performance. By observing the morphology of oil droplets deposited layer after different operation conditions and the behavior of oil droplets at the electrode surface under different voltage conditions, the mechanism was proposed that the oil droplets first accumulated on the surface of flow-through electrode by sieving effect, subsequently the gathered oil droplets could further coalesce with the promoting effect of the anode, leading to a high-performing demulsification. This study offers an attractive option of using flow-through electrode to accomplish the oil recovery with simultaneous water purification.
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Affiliation(s)
- Xi Li
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Gong Zhang
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Chengzhi Hu
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Huachun Lan
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Huijuan Liu
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
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Li X, Zhang G, Liu H, Lan H, Qu J. Sequential Demulsification through the Hydrophobic-Hydrophilic-Hydrophobic Filtration Layer toward High-Performing Oil Recovery. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:12083-12093. [PMID: 37530558 DOI: 10.1021/acs.est.3c02098] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/03/2023]
Abstract
Demulsification using membranes is a promising method to coalesce highly stable emulsified oil droplets for oil recovery. Nevertheless, a structure of the current filtration medium that is not efficient for oil droplet coalescence impedes rapid permeability, thereby inevitably restricting their practical applications. Herein, we report a hydrophobic-hydrophilic-hydrophobic (3H) demulsification medium that exhibits a benchmark permeability of ∼2.1 × 104 L m-2 h-1 with a demulsification efficiency of >98.0%. Remarkably, this 3H demulsification medium maintains over 90% demulsification efficiency in the oil-in-water (O/W) emulsions with a wide range of surfactant concentrations, which shows excellent applicability. Based on the combined results of quasi situ microscope images and molecular dynamics simulations, we show that the polydimethylsiloxane-modified hydrophobic layer facilitates the capture and coalescence of oil droplets, the hydrophilic inner layer assists in squeezing the coalescence of enlarged droplets, and the third hydrophobic layer accelerates the discharge of demulsified oil to sustain permeability. The sequential demulsification mechanism between this 3H filtration layer provides a general guide for designing a demulsifying membrane with high demulsification efficiency and high flux toward oil recovery.
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Affiliation(s)
- Xi Li
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Gong Zhang
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Huijuan Liu
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Huachun Lan
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Jiuhui Qu
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
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Duan F, Zhu Y, Lu Y, Xu J, Wang A. Fabrication porous adsorbents templated from aqueous foams using astragalus membranaceus and attapulgite as stabilizer for efficient removal of cationic dyes. J Environ Sci (China) 2023; 127:855-865. [PMID: 36522113 DOI: 10.1016/j.jes.2022.08.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 07/22/2022] [Accepted: 08/01/2022] [Indexed: 06/17/2023]
Abstract
The water-based foam stabilized by the natural surfactant applied in the fabrication of porous materials has attracted extensive attention, as the advantages of cleanness, convenience and low cost. Particularly, the development of a green preparation method has became the main research focus and frontier. In this work, a green liquid foam with high stability was prepared by synergistic stabilization of natural plant astragalus membranaceus (AMS) and attapulgite (APT), and then a novel porous material with sufficient hierarchical pore structure was templated from the foam via a simple free radical polymerization of acrylamide (AM). The characterization results revealed that the amphiphilic molecules from AMS adsorbed onto the water-air interface and formed a protective shell to prevent the bubble breakup, and APT gathered in the plateau border and formed a three-dimensional network structure, which greatly slowed down the drainage rate. The porous material polyacrylamide/astragalus membranaceus/attapulgite (PAM/AMS/APT) showed the excellent adsorption performance for cationic dyes of Methyl Violet (MV) and Methylene Blue (MB) in water, and the maximum adsorption capacity could reach to 709.13 and 703.30 mg/g, respectively. Furthermore, the polymer material enabled to regenerate and cycle via a convenient calcination process, and the adsorption capacity was still higher than 200 mg/g after five cycles. In short, this research provided a new idea for the green preparation of porous materials and the treatment of water pollution.
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Affiliation(s)
- Fangzhi Duan
- Key Laboratory of Clay Mineral Applied Research of Gansu Province, Center of Eco-material and Green Chemistry, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China; Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yongfeng Zhu
- Key Laboratory of Clay Mineral Applied Research of Gansu Province, Center of Eco-material and Green Chemistry, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
| | - Yushen Lu
- Key Laboratory of Clay Mineral Applied Research of Gansu Province, Center of Eco-material and Green Chemistry, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Jiang Xu
- Key Laboratory of Clay Mineral Applied Research of Gansu Province, Center of Eco-material and Green Chemistry, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Aiqin Wang
- Key Laboratory of Clay Mineral Applied Research of Gansu Province, Center of Eco-material and Green Chemistry, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
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Qi Z, Sun Z, Li N, Chen Q, Liu W, Li W. Effect of inorganic salt concentration and types on electrophoretic migration of oil droplets in oil-in-water emulsion: A molecular dynamics study. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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5
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Wang Y, Li S, Zhang Y, Zhang Z, Yuan S, Wang D. Effect of electric field on coalescence of an oil-in-water emulsion stabilized by surfactant: a molecular dynamics study. RSC Adv 2022; 12:30658-30669. [PMID: 36337949 PMCID: PMC9597590 DOI: 10.1039/d2ra04731d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 10/18/2022] [Indexed: 11/07/2022] Open
Abstract
The microscopic understanding of electrocoalescence of oil-in-water (O/W) emulsions stabilized by surfactant is very important to improve the efficiency of electrical demulsification. The behaviors of the coalescence of O/W emulsion stabilized by surfactant in the presence of a direct electric field and a pulsed electric field were explored by nonequilibrium molecular dynamics simulations. According to the simulated results, an electrical method is feasible to demulsify an O/W emulsion stabilized by a surfactant. The configuration and movement of the sodium dodecyl sulfate (SDS) were determined by interactions between SDS molecules themselves and between SDS and oil/water molecules along with the force exerted by the applied electrical field. Two droplets will coalesce into one when the strength of the electric field exceeds 0.4 V nm-1. The SDS group can be broken up by an electric field larger than 0.6 V nm-1. The point when interaction energy between the hexadecane molecules of the two droplets begins to decrease from zero is consistent with the time when the two oil droplets came in contact. The coalescence process can be completed if the two droplets have begun to coalesce, even after the electric field was removed. Otherwise, the coalescence process cannot be completed. To enhance the efficiency of the electrocoalescence of O/W emulsions, strength, frequency and duty ratio of the electric field have to be optimized according to the properties of the emulsion. This research will help us to figure out how electric fields promote the efficiency of electrocoalescence of O/W emulsions with surfactant.
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Affiliation(s)
- Yudou Wang
- College of Science, China University of Petroleum (East China) Qingdao 266580 China
| | - Shiyan Li
- College of Science, China University of Petroleum (East China) Qingdao 266580 China
| | - Yuanwu Zhang
- College of Science, China University of Petroleum (East China) Qingdao 266580 China
| | - Zhenlei Zhang
- College of Science, China University of Petroleum (East China) Qingdao 266580 China
| | - Shundong Yuan
- College of Science, China University of Petroleum (East China) Qingdao 266580 China
| | - Diansheng Wang
- College of Science, China University of Petroleum (East China) Qingdao 266580 China
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Li W, Zeng H, Tang T. Molecular dynamics simulation on water/oil interface with model asphaltene subjected to electric field. J Colloid Interface Sci 2022; 628:924-934. [PMID: 35963177 DOI: 10.1016/j.jcis.2022.08.027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 07/24/2022] [Accepted: 08/04/2022] [Indexed: 11/15/2022]
Abstract
HYPOTHESIS The droplet-medium interfaces of petroleum emulsions are often stabilized by the indigenous surface-active compounds (e.g., asphaltenes), causing undesired issues. While demulsification by electric field is a promising technique, fundamental study on the droplet-medium interface influenced by electric field is limited. Molecular dynamics (MD) simulations are expected to provide microscopic insights into the nano-scaled water/oil interface. METHODS MD simulations are conducted to study the adsorption of model asphaltene molecules (represented by N-(1-hexylheptyl)-N'-(5-carboxylicpentyl) perylene-3,4,9,10-tetracarboxylic bisimide (C5Pe)) on a water-toluene interface under various strengths of electric field. The adsorption amount and structural feature of C5Pe molecules at water-toluene interface are investigated, and the effects of electric field and salt are discussed. FINDINGS C5Pe molecules tend to adsorb on the water-oil interface. As the electric field strength increases, the adsorption amount first slightly increases (or remains constant) and then decreases. The electric field disrupts the compact π-π stacking between C5Pe molecules and increases their mobility, causing a dispersed distribution of the molecules with a wide range of orientations relative to the interface. Within the studied range, the addition of salt ions appears to stabilize the interface at high electric field. These results provide useful insights into the mechanism and feasibility of demulsification under electric field.
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Affiliation(s)
- Wenhui Li
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada
| | - Hongbo Zeng
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada.
| | - Tian Tang
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada.
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Wang Y, Liu X, He Q, Wang X, Lu H, Guo F, Zhang Y, Wang W. Multifunctional natural sepiolite nanofibre composite demulsifiers for efficient purification of oils and dyes in simulated and actual wastewater. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.120865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Zhao Y, Gu Y, Gao G. Piezoelectricity induced by pulsed hydraulic pressure enables in situ membrane demulsification and oil/water separation. WATER RESEARCH 2022; 215:118245. [PMID: 35290871 DOI: 10.1016/j.watres.2022.118245] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 02/23/2022] [Accepted: 03/01/2022] [Indexed: 05/25/2023]
Abstract
Recovering oil from oily wastewater is not only for economic gains but also for mitigating environmental pollution. However, demulsification of oil droplets stabilized with surfactants is challenging because of their low surface energy. Although the widely used oil/water separation membrane technologies based on size screening have attracted considerable attention in the past few decades, they are incapable of demulsification of stabilized oil emulsions and the membrane concentrates often require post-processing. Herein, the piezoelectric ceramic membrane (PCM), which can respond to the inherent transmembrane pressure in the pressure-driven membrane processes, was employed to transform hydraulic pressure pulses into electroactive responses to in situ demulsification. The pulsed transmembrane pressure on the PCM results in the generation of considerable rapid voltage oscillations over 3.2 V and a locally high electric field intensity of 7.2 × 107 V/m, which is capable of electrocoalescence with no additional stimuli or high voltage devices. Negative dielectrophoresis (DEP) force occurred in this membrane process and repelled the large size of oil after demulsification away from the PCM surface, ensuring continuous membrane demulsification and oil/water separation. Overall, PCM provides a further opportunity to develop an environmentally friendly and energy-saving electroresponsive membrane technology for practical applications in wastewater treatment.
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Affiliation(s)
- Yang Zhao
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Yuna Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Guandao Gao
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China; Research Center for Environmental Nanotechnology (ReCENT), Nanjing University, Nanjing 210023, China.
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9
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Liu S, Yuan S, Zhang H. Molecular Dynamics Simulation for the Demulsification of O/W Emulsion under Pulsed Electric Field. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27082559. [PMID: 35458757 PMCID: PMC9029195 DOI: 10.3390/molecules27082559] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 04/04/2022] [Accepted: 04/12/2022] [Indexed: 11/18/2022]
Abstract
A bidirectional pulsed electric field (BPEF) method is considered a simple and novel technique to demulsify O/W emulsions. In this paper, molecular dynamics simulation was used to investigate the transformation and aggregation behavior of oil droplets in O/W emulsion under BPEF. Then, the effect of surfactant (sodium dodecyl sulfate, SDS) on the demulsification of O/W emulsion was investigated. The simulation results showed that the oil droplets transformed and moved along the direction of the electric field. SDS molecules can shorten the aggregation time of oil droplets in O/W emulsion. The electrostatic potential distribution on the surface of the oil droplet, the elongation length of the oil droplets, and the mean square displacement (MSD) of SDS and asphaltene molecules under an electric field were calculated to explain the aggregation of oil droplets under the simulated pulsed electric field. The simulation also showed that the two oil droplets with opposite charges have no obvious effect on the aggregation of the oil droplets. However, van der Waals interactions between oil droplets was the main factor in the aggregation.
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Affiliation(s)
- Shasha Liu
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China; (S.L.); (S.Y.)
- School of Chemistry and Chemical Engineering, Qilu Normal University, Jinan 250100, China
| | - Shiling Yuan
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China; (S.L.); (S.Y.)
| | - Heng Zhang
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China; (S.L.); (S.Y.)
- Correspondence:
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10
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Yang D, Wu H, Sun H, He L, Guo Y. Ultra-high frequency and Self-adaptive voltage technology for water separation from oil emulsion. Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2021.119732] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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11
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Delamination-Free In-Air and Underwater Oil-Repellent Filters for Oil-Water Separation: Gravity-Driven and Cross-Flow Operations. ENERGIES 2021. [DOI: 10.3390/en14217429] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Separating oil-water mixtures is critical in a variety of practical applications, including the treatment of industrial wastewater, oil spill cleanups, as well as the purification of petroleum products. Among various methodologies that have been utilized, membranes are the most attractive technology for separating oil-water emulsions. In recent years, selective wettability membranes have attracted particular attention for oil-water separations. The membrane surfaces with hydrophilic and in-air oleophobic wettability have demonstrated enhanced effectiveness for oil-water separations in comparison with underwater oleophobic membranes. However, developing a hydrophilic and in-air oleophobic surface for a membrane is not a trivial task. The coating delamination process is a critical challenge when applying these membranes for separations. Inspired by the above, in this study we utilize poly(ethylene glycol)diacrylate (PEGDA) and 1H,1H,2H,2H-heptadecafluorodecyl acrylate (F-acrylate) to fabricate a hydrophilic and in-air oleophobic coating on a filter. We utilize methacryloxypropyl trimethoxysilane (MEMO) as an adhesion promoter to enhance the adhesion of the coating to the filter. The filter demonstrates robust oil repellency preventing oil adhesion and oil fouling. Utilizing the filter, gravity-driven and continuous separations of surfactant-stabilized oil-water emulsions are demonstrated. Finally, we demonstrate that the filter can be reused multiple times upon rinsing for further oil-water separations.
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Feng K, Gao N, Li W, Dong H, Sun F, He G, Zhou K, Zhao H, Li G. Arrested Coalescence of Ionic Liquid Droplets: A Facile Strategy for Spatially Organized Multicompartment Assemblies. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2104385. [PMID: 34643335 DOI: 10.1002/smll.202104385] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 09/01/2021] [Indexed: 06/13/2023]
Abstract
Multicompartment assemblies attract much attention for their wide applications. However, the fabrication of multicompartment assemblies usually requires elaborately designed building blocks and careful controlling. The emergence of droplet networks has provided a facile way to construct multiple droplet architectures, which can further be converted to multicompartment assemblies. Herein, the bind motif-free building blocks are presented, which consist of the hydrophobic Tf2 N- -based ionic liquid (IL) dissolving LiTf2 N salt, that can conjugate via arrested coalescence in confined-space templates to form IL droplet networks. Subsequent ultraviolent polymerization generates robust free-standing multicompartment assemblies. The conjugation of building blocks relies not on the peripheral bind motif but on the interfacial instability-induced arrested coalescence, avoiding tedious surface modification and assembly process. By tuning structures of templates and building blocks, multicompartment assemblies with 0D, 1D, 2D, and 3D structures are prepared in a facile and high-throughput way. Importantly, the bottom-up construction enables modular control over the compositions and spatial positions of individual building blocks. Combining with the excellent solvency of ILs, this system can serve as a general platform towards versatile multicompartment architectures. As demonstrations, by tailoring the chambers the multicompartment assemblies can spatiotemporally sense and report the chemical cues and perform various modes of motion.
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Affiliation(s)
- Kai Feng
- Department of Chemistry, Key Lab of Organic Optoelectronics & Molecular Engineering, Tsinghua University, Beijing, 100084, China
| | - Ning Gao
- Department of Chemistry, Key Lab of Organic Optoelectronics & Molecular Engineering, Tsinghua University, Beijing, 100084, China
| | - Wenyun Li
- Department of Chemistry, Key Lab of Organic Optoelectronics & Molecular Engineering, Tsinghua University, Beijing, 100084, China
| | - Hao Dong
- Department of Chemistry, Key Lab of Organic Optoelectronics & Molecular Engineering, Tsinghua University, Beijing, 100084, China
| | - Fuwei Sun
- Department of Chemistry, Key Lab of Organic Optoelectronics & Molecular Engineering, Tsinghua University, Beijing, 100084, China
| | - Guokang He
- Department of Chemistry, Key Lab of Organic Optoelectronics & Molecular Engineering, Tsinghua University, Beijing, 100084, China
| | - Kang Zhou
- Department of Chemistry, Key Lab of Organic Optoelectronics & Molecular Engineering, Tsinghua University, Beijing, 100084, China
| | - Hongwei Zhao
- Department of Chemistry, Key Lab of Organic Optoelectronics & Molecular Engineering, Tsinghua University, Beijing, 100084, China
| | - Guangtao Li
- Department of Chemistry, Key Lab of Organic Optoelectronics & Molecular Engineering, Tsinghua University, Beijing, 100084, China
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Wang R, Fu M, Yang J, Zhong Y, Zhang R, Zhang Q, Liu Y, Zhou Y. Surface Charge Regulation of MIL-100(Fe) by Anion Exchange for Demulsifying the Cationic Surfactant-Stabilized O/W Emulsion. ACS APPLIED MATERIALS & INTERFACES 2021; 13:49964-49973. [PMID: 34652892 DOI: 10.1021/acsami.1c14602] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Demulsifying ionic surfactant-stabilized emulsions remains an emerging issue due to the stringent electrostatic barriers. In this work, a phosphate-mediated anion exchange strategy was proposed to fabricate a metal-organic framework, MIL-100(Fe), with adjustable surface charge for effective demulsification toward a cationic surfactant-stabilized emulsion. By adjusting the pH of the phosphate precursor solution, the surface charge of MIL-100(Fe) can be fine-tuned. At pH 3.0, the phosphate-exchanged MIL-100(Fe) with the zeta potential decreasing from 21.4 to 6.1 mV exhibited a significant enhancement of the demulsification efficiency (DE) from 35 to 91%. Further elevating the pH to 9.0 results in the zeta potential of the phosphate-exchanged MIL-100(Fe) to be reversed to -2.0 mV, and the DE can be optimized to 96% within 5 min. The demulsification mechanism was systematically explored based on the zeta potential, distribution of the surfactant, viscoelastic modulus evaluation, and morphological characterization of the emulsion in combination with monitoring of the dynamics process of demulsification. It was found that the phosphate-exchanged MIL-100(Fe) captured by the emulsion can lead to the release of the surfactant and heterogenization of the interfacial film, causing the elasticity of the emulsion to decrease and the irreversible deformation of emulsion droplets. Consequently, the destabilized emulsion could be subjected to the effective demulsification either by the fusion pathway mediated by the phosphate-exchanged MIL-100(Fe) or direct rupture. This work emphasized a facile and promising approach to deal with the cationic surfactant-emulsified oily wastewater and disclosed the fundamental demulsification process.
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Affiliation(s)
- Rui Wang
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan Province 610500, China
- Carbon Neutralization Research Institute, School of New Energy and Materials, Southwest Petroleum University, Chengdu, Sichuan Province 610500, China
| | - Miao Fu
- Carbon Neutralization Research Institute, School of New Energy and Materials, Southwest Petroleum University, Chengdu, Sichuan Province 610500, China
| | - Juncai Yang
- Carbon Neutralization Research Institute, School of New Energy and Materials, Southwest Petroleum University, Chengdu, Sichuan Province 610500, China
| | - Yunqian Zhong
- Carbon Neutralization Research Institute, School of New Energy and Materials, Southwest Petroleum University, Chengdu, Sichuan Province 610500, China
| | - Ruiyang Zhang
- Carbon Neutralization Research Institute, School of New Energy and Materials, Southwest Petroleum University, Chengdu, Sichuan Province 610500, China
| | - Qian Zhang
- Carbon Neutralization Research Institute, School of New Energy and Materials, Southwest Petroleum University, Chengdu, Sichuan Province 610500, China
| | - Yucheng Liu
- College of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu, Sichuan Province 610500, China
| | - Ying Zhou
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan Province 610500, China
- Carbon Neutralization Research Institute, School of New Energy and Materials, Southwest Petroleum University, Chengdu, Sichuan Province 610500, China
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14
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Lv Y, Guo K, Li Q, Zhao J. A continuous phase with better performance for photographing the dynamic behavior of droplets in oil: Poly (methylhydrosiloxane). Colloids Surf A Physicochem Eng Asp 2021. [DOI: 10.1016/j.colsurfa.2021.127199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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15
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Enhancing oil-in-water emulsion separation performance of polyvinyl alcohol hydrogel nanofibrous membrane by squeezing coalescence demulsification. J Memb Sci 2021. [DOI: 10.1016/j.memsci.2021.119324] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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16
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Lu H, Pan Z, Miao Z, Xu X, Wu S, Liu Y, Wang H, Yang Q. Combination of electric field and medium coalescence for enhanced demulsification of oil-in-water emulsion. CHEMICAL ENGINEERING JOURNAL ADVANCES 2021. [DOI: 10.1016/j.ceja.2021.100103] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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17
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Zhao Z, Kang Y, Wu S, Sheng K. Demulsification performance of oil-in-water emulsion in bidirectional pulsed electric field with starlike electrodes arrangement. J DISPER SCI TECHNOL 2021. [DOI: 10.1080/01932691.2021.1915156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Zihao Zhao
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, China
| | - Yong Kang
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Siyu Wu
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, China
| | - Kai Sheng
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, China
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Zhu X, Zhu L, Li H, Xue J, Ma C, Yin Y, Qiao X, Sun D, Xue Q. Multifunctional charged hydrogel nanofibrous membranes for metal ions contained emulsified oily wastewater purification. J Memb Sci 2021. [DOI: 10.1016/j.memsci.2020.118950] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Hu J, Chen J, Zhang X, Xiao J, An S, Luan Z, Liu F, Zhang B. Dynamic demulsification of oil-in-water emulsions with electrocoalescence: Diameter distribution of oil droplets. Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2020.117631] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Kim S, Kim K, Jun G, Hwang W. Wood-Nanotechnology-Based Membrane for the Efficient Purification of Oil-in-Water Emulsions. ACS NANO 2020; 14:17233-17240. [PMID: 33269587 DOI: 10.1021/acsnano.0c07206] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
With increasing amounts of oily water discharged from industrial and domestic sources, purifying oily emulsions using effective and eco-friendly methods is of great significance. Although functional membranes with selective wettabilities have been extensively explored for the efficient purification of oil-in-water emulsions, the development of functional membranes that use green and inexpensive materials, are simple to fabricate, and are easy to scale up remains very challenging. Herein, we report a simple approach that uses biomass to prepare a membrane for the purification of emulsions. A simple top-down approach was used to partially remove lignin and hemicellulose fractions in wood sheets, resulting in a highly porous and flexible wood membrane. The obtained wood membrane shows excellent water-absorbing and underwater anti-oil adhesion properties due to the removal of the hydrophobic lignin. The wood membrane is durable and stable, thereby maintaining its selective wettability in harsh environments. Selective wetting properties along with a porous structure enable the wood membrane to purify surfactant-stabilized oil-in-water emulsions. Such a biomass-derived membrane, which is green, inexpensive, easy to fabricate, and scalable, along with its selective wettability and durability, shows great potential for use as a substitute for existing filter media in diverse industries.
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Affiliation(s)
- Seongmin Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Kihwan Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Gyosik Jun
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Woonbong Hwang
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
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Huang X, He L, Luo X, Xu K, Lü Y, Yang D. Charge-Transfer-Induced Noncoalescence and Chain Formation of Free Droplets under a Pulsed DC Electric Field. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:14255-14267. [PMID: 33206532 DOI: 10.1021/acs.langmuir.0c02371] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Electrocoalescence technology is an important method for the demulsification of crude oil emulsion, but its development is restricted by the short circuit caused by droplet chain formation. To reveal the formation mechanism of droplet chains, the electrocoalescence behaviors of two droplets and droplet clusters under pulsed direct current (DC) electric fields are experimentally studied. The two droplets usually successively undergo complete coalescence, partial coalescence, and noncoalescence as the electric field strength increases. The critical electric field strengths for complete coalescence under pulsed DC electric fields with different frequencies are obtained. The effects of the electric field waveform and frequency on the noncoalescence characteristics of two droplets and the stability of droplet chains are explored. The droplet chains under a high-frequency electric field are more stable and longer than those under a low-frequency electric field due to the reduction of the movement distance and the generation of daughter droplets from tip streaming. The reversal of the composition of electric forces due to charge transfer is the fundamental mechanism of noncoalescence of two droplets and chain formation in the emulsion under a pulsed DC electric field.
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Affiliation(s)
- Xin Huang
- College of Pipeline and Civil Engineering, China University of Petroleum (East China), Qingdao 266580, China
| | - Limin He
- College of Pipeline and Civil Engineering, China University of Petroleum (East China), Qingdao 266580, China
- Surface Engineering Pilot Test Center, China National Petroleum Corporation, Daqing 163000, China
| | - Xiaoming Luo
- College of Pipeline and Civil Engineering, China University of Petroleum (East China), Qingdao 266580, China
- Surface Engineering Pilot Test Center, China National Petroleum Corporation, Daqing 163000, China
| | - Ke Xu
- College of Pipeline and Civil Engineering, China University of Petroleum (East China), Qingdao 266580, China
| | - Yuling Lü
- College of Pipeline and Civil Engineering, China University of Petroleum (East China), Qingdao 266580, China
- Surface Engineering Pilot Test Center, China National Petroleum Corporation, Daqing 163000, China
| | - Donghai Yang
- College of Pipeline and Civil Engineering, China University of Petroleum (East China), Qingdao 266580, China
- Surface Engineering Pilot Test Center, China National Petroleum Corporation, Daqing 163000, China
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Jin W, Wang Z, Peng D, Shen W, Zhu Z, Cheng S, Li B, Huang Q. Effect of pulsed electric field on assembly structure of α-amylase and pectin electrostatic complexes. Food Hydrocoll 2020. [DOI: 10.1016/j.foodhyd.2019.105547] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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23
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Demulsification-induced Fast Solidification: a Novel Strategy for Preparation of Polymer Encapsulations. Chem Res Chin Univ 2019. [DOI: 10.1007/s40242-019-9167-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Wang D, Ge X, Nie H, Yao Z, Zhang J. Demulsification-induced fast solidification: a novel strategy for the preparation of polymer films. Chem Commun (Camb) 2019; 55:9192-9195. [PMID: 31309216 DOI: 10.1039/c9cc03925b] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
We demonstrate a novel, simple and convenient demulsification-based method called demulsification-induced fast solidification (DIFS) to fabricate polymer films. Two dimensional films, three dimensional films, and free-standing polyvinyl acetate and polyurethane acrylate films were fabricated via electrochemical deposition using the DIFS method.
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Affiliation(s)
- Dan Wang
- School of Chemistry and Environmental Engineering, Changchun University of Science and Technology, Changchun 130022, P. R. China.
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