ACS Omega
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2024
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IF 3.7
Nana Sun,Huina Sun,Jianbo Hu,Shiqi Xu,Lisha Shen,Yuli Ma
In this study, cationic polyacrylamide (CPAM)-coated magnetic nanoparticles (MNPs) Fe3O4@CPAM were synthesized for treating heavy O/W emulsions. This Fe3O4@CPAM was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and vibrating sample magnetometry (VSM) techniques, and its synergistic performances with microwaves were evaluated in detail with respect to the microwave radiation power, radiation time, and magnetic nanoparticle concentration. On this basis, the distribution of oil droplets and the wettability and chargeability of magnetic nanoparticles were measured without or with microwave radiation using biomicroscopy, contact angle measurement instrument, and a ζ-potential analyzer, thus revealing the synergistic demulsification mechanism between microwave and magnetic nanoparticles. The results showed that excessively high or low microwave radiation parameters had an inhibitory effect on the magnetic nanoparticle demulsification, and microwave promoted the magnetic nanoparticle demulsification only when the radiation parameters were in the optimal range. In addition, the water separation rate showed an increasing and then decreasing trend with the increase of magnetic nanoparticles concentration, with or without microwave action. As an example, the water separation rate of the emulsion for 1 h was 21.34% when the Fe3O4 concentration was 175 mg/L without microwave action, while it increased to 55.56% with microwave action. In contrast, when the concentration of Fe3O4@CPAM was 175 mg/L, the water separation rate was 42.86% without microwave radiation, while it was further increased to 77.38% under microwave radiation. These results indicate that magnetic nanoparticles and their complexes significantly affect the water separation process under different conditions. There is a more obvious coupling synergistic effect between Fe3O4@CPAM and microwave. This was due to the lower absolute potential of Fe3O4@CPAM and its higher hydrophobicity.
研究领域:
环境科学
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材料科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2023
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IF 6
Xueying Zhang,Junyan Wang,Xincheng Zhang,Lin He,Hong Sui,Xingang Li
The fine mineral particles often coexist in oil-water emulsions, enhancing the stability of oil-water emulsions. Herein, the micro SiO 2 was used to investigate its synergistic effects with the interfacially-active asphaltenes (IAA) on forming the strong interfacial film at the oil–water interface. This IAA-particle film showed high rigidity, allowing the emulsion droplets (4 μm − 20 μm) to be much more stable than the traditional asphaltene-stabilized emulsions. With the addition of the oxygen containing demulsifier (MJTJU-2, an alternated aliphatic alcohol nonionic polyether), this kind of emulsion could be broken significantly (over 99 % at the demulsifier concentration > 600 ppm and settling time > 45 min) with almost all of the microparticles transferring from oil phase to the water phase as particle net-like film. The optimal concentration (1000 ppm) of demulsifier were obtained. Further mechanistic study by QCM-D suggested that the desorption process of asphaltenes from solid surface could be divided into three main stages: the demulsifier molecules adsorbed and penetrated into the IAA adsorption film on solid surface; the simultaneous desorption of the adsorbed IAA and pre-adsorbed demulsifiers; the IAA film became loose and was destructed by the demulsifiers. AFM tests found that after addition of demulsifiers, the surface force between IAA and silica (0.0589 mN/m) decreased about 37 %. The MD simulation results showed that the demulsifier molecules would adsorb on the IAA film firstly by van der Waals and hydrogen bond, making the film much looser. The demulsifier could interact with the IAA molecule, resulting in desorption of IAA. Simultaneously, the demulsifier could compete for the adsorption sites on the IAA molecules by forming new hydrogen bonds, which destroyed the IAA adsorption layer. As a result, the stable IAA-solid film at oil–water interface could be broken. These findings would provide fundamental understanding to the stability and instability of IAA-solids co-stabilized oil–water emulsions, oil-sludge treatments.
研究领域:
化学工程
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材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2024
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IF 5.3
Jie Ma,Tao Wang,Wei Hou,Zhenhua Wu,Suling Bao,Dan Wu,Wentao Ma,Yu Zhang
The extraction of crude oil generates a significant volume of stable emulsions that can lead to various adverse effects in industrial extraction processes. Therefore, emulsion demulsification is a crucial step. In this paper, PGDA, a low-temperature W/O demulsifier with double hydrophobic chains, was synthesized from poly(ethylene glycol) diacrylate by a simple low-temperature process. The structure of PGDA was analyzed by FTIR and 1 H NMR, and the demulsification performance was evaluated by a bottle-testing method. The results demonstrated that PGDA, at a concentration of 500 mg/L, achieved a demulsification efficiency of 100 % under low-temperature conditions (45 °C) over a 5-hour period. Furthermore, it also showed good demulsifying performance in wide pH range (6–10) and high salinity (100,000 mg/L). In addition, the possible mechanism of demulsification of PGDA was investigated by zeta potential, interfacial tension, and three-phase contact angle, etc. PGDA showed strong competitive adsorption ability with asphaltenes at the interface. PGDA has the ability to navigate rapidly to the oil–water boundary and displace the native surfactants there, thus destabilizing the emulsion and thus promoting the separation of oil and water. PGDA by virtue of the simple synthesis process, low demulsification temperature and high efficiency are of practical application.
研究领域:
化学工程
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石油工程
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产品关联
DOI
高影响因子
Frontiers in Materials
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2022
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IF 3.985
Tan Wei,Zhu Songxiang,Kong Lingyun,Peng Yi,Xu Lei,Fu Yaoguo
Efficient demulsification is vital for the application of emulsified asphalt in road construction. In this paper, the effects of the main chemical components of the aggregates (CaCO3, MgO, Fe2O3, SiO2, Al2O3) on the demulsification process of emulsified asphalt were studied by experiment and simulation using a Gompertz model. The findings indicate that the surface energy, specific surface area, and pH of the chemical components of the aggregates are the most important factors influencing the demulsification speed of the emulsified asphalt. The choice of the aggregate’s main chemical components can accelerate demulsification speed, with the acceleration effect of Al2O3 on anionic (SDBS) emulsified asphalt and MgO on cationic (STAC) emulsified asphalt both reaching 60%. The fit between the Gompertz model and the experimental viscosity curve is greater than 0.93, which verifies the utility of using the Gompertz approach for studying emulsified asphalt-aggregate mortar viscosity changes. A demulsification evaluation function φ(t) of emulsified asphalt is proposed based on the parameters of the Gompertz model. When φ(t) is close to 1, the emulsified asphalt-aggregate mortar is fully demulsified, and setting φ(t)=1 allows the demulsification time of the emulsified asphalt-aggregate mortar to be calculated from the Gompertz model parameters.
研究领域:
材料科学
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土木工程
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2020
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IF 5.774
Jianlong Hu,Jiaqing Chen,Xue Zhang,Jianhong Xiao,Shenfa An,Zhiyong Luan,Fan Liu,Baosheng Zhang
The oil-in-water (O/W) emulsions, especially oily wastewater from EOR oilfield, generally contain small oil droplets in the continuous water phase, which is difficult to be removed with conventional oil separation process such as precipitation, flotation. The electrostatic coalescence is a promising pretreatment step to induce the oil droplets coalescence and promote the oil separation efficiency of conventional methods. In order to explore the feasibility of electrostatic demulsification for O/W emulsions, the influence of operating parameters including electric voltage, pulsatile frequency, water content of emulsions and hydraulic retention time (HRT) on oil diameter distribution of the emulsions were studied using dynamic demulsification experiment. The volume percentage of oil droplets with a diameter exceeding 40 μm (denoted as DG40) was adopted as the main indicator of demulsification results, it increased from 0 (the original emulsions) to 65.62% (the treated emulsions) at the optimal operation parameters including water content of emulsions 90 vol%, electric voltage 150 V, pulsatile frequency 1000 Hz, duty cycle ratio 0.5, hydraulic retention time (HRT) 60 s. Furthermore, the water separation efficiency for emulsions reached 82.5% at 11 min of the dynamic experiment duration. The results of this study showed that applying pulsatile electric field could be a feasible and effective technology for emulsified oil droplets coalescence in O/W emulsions.
研究领域:
环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
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2024
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IF 10.8
Yuna Gu,Qiancheng Xia,Bin Liu,Yang Zhao,Liangtao Pu,Jie Ding,Yanbiao Liu,Enze Li,Chad D. Vecitis,Guandao Gao
Demulsification technology for separation of oil–water (O/W) emulsions, especially those stabilized by surfactants, is urgently needed yet remains highly challenging due to their inherent stability characteristics. Electrocoalescence has emerged as a promising solution owing to its simplicity, efficacy, and versatility, yet hindered by substantial energy consumption (e.g., >50 kWh/m3) along with undesirable Faradic reactions. Herein, we propose an innovative electric demulsification technology that leverages conductive membrane microchannels to confine oil droplets from the oil–water emulsion for achieving high energy-efficient coalescence of oil droplets. The proposed system reduces the required voltage down to 12 V, 2 orders of magnitude lower than that of conventional electrocoalescence systems, while achieving a similar separation efficacy of 91.4 ± 3.0% at a low energy consumption (3 kWh/m3) and an ultrahigh permeability >3000 L/(m2·h·bar). In situ fluorescence microscopy combined with COMSOL simulations provided insight into the fundamental mechanistic steps of an electric demulsification process confined to membrane microchannels: (1) rapid electric-field redistribution of oil droplet surfactant molecules, (2) enhanced collision probability due to confined oil droplet concentration under dielectrophoretic forces, and (3) increased collision efficacy facilitated by the membrane pore structure. This strategy may revolutionize the next generation of demulsification and oil–water separation innovations.
研究领域:
环境科学
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化学工程
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2024
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IF 8.4
Hui Li,Shaopeng Gan,Jianqiang Zhang,Kangxing Wei,Xu Zhu,Xilu Liu,Lei Zhu,Hongbo Zeng,Qingzhong Xue
Advanced membranes are urgently needed in concentration, purification and separation of various industrial emulsions. However, their performance is impeded by issues such as membrane fouling and the inherent trade-off between separation efficiency and permeation flux. In this work, an interfacial demulsification and antifouling membrane was achieved through self-releasing high concentration of hydroxide ions on the membrane surface in a dynamic manner. These hydroxide ions can facilitate the emulsified oil droplets on the membrane surface to demulsify by greatly decreasing their Debye length and suppressing their electric double layer repulsion. In this way, the emulsified oil droplets could aggregate into large ones and rapidly detach from the membrane surface, mitigating the challenges of membrane fouling and trade-off. Thus, the membrane exhibits outstanding antifouling ability, achieving high efficiency (99.79 %) and flux (3046 L m −2 h −1 bar −1 ) in long-term oil/water emulsion separation. This ionic self-releasing membrane is easy to manage, requires no reagent consumption, and causes no pollution. This work provides a promising solution and valuable insights into membrane separation and emulsion-related systems.
研究领域:
材料科学
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环境工程
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Water Process Engineering
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2023
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IF 7
Hao Sun,Xiaoqing Li,Xiaobing Li
The asphaltene-rich alkaline-surfactant-polymer (ASP) flooding produced water has been identified with high interfacial stability and severe secondary emulsification, which poses great difficulties in its demulsification process. This leads to an urgent need to develop targeted and efficient demulsifiers. In this research, a novel polydopamine-polyquaternium modified Fe 3 O 4 (PQA-PDA@Fe 3 O 4 ) nanoparticle integrates the electrical neutralization, interfacial adsorption and magnetic aggregation functionalities was prepared to dispose this emulsion. Primarily, structural and surface properties of the PQA-PDA@Fe 3 O 4 demulsifier were systemically characterized by a series of analytical techniques, which presents its core-shell, hydrophilic and positively charged characters. When employing PQA-PDA@Fe 3 O 4 to treat the produced water that contained 500 mg/L emulsified oil, a demulsification efficiency of 90.5 % was achieved at 200 mg/L dosage. It was found that the PQA-PDA@Fe 3 O 4 nanoparticles could coalesce the fine oil droplets into large and dense aggregates, as demonstrated by the raised fractal dimension values. By monitoring the interfacial properties (interfacial tension, zeta potential and interfacial film elastic modulus) variations, the demulsification mechanism was further explored. The PQA-PDA@Fe 3 O 4 nanoparticle could spontaneously migrate to the oil/water interface and reassemble a loose interfacial film, thus leading the oil droplets destabilization and aggregation. Notably, the magnetic force between the PQA-PDA@Fe 3 O 4 nanoparticles significantly accelerates the oil droplets aggregation and inhibits the secondary emulsification process, so as to achieve the outstanding demulsification efficiency. Moreover, this PQA-PDA@Fe 3 O 4 nanoparticle exhibited acceptable magnetic recyclability. These results provided an effective and alternative protocol to demulsify the asphaltene-rich ASP flooding emulsions.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
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2021
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IF 7.086
Rui Wang,Yuxuan Cai,Zhi Su,Xiaoli Ma,Wei Wu
Oily wastewater not only causes major environmental issues , but also threatens human health. Magnetic nanoparticles (MNPs) are an attractively alternative commercial demulsifiers for their recyclability and high surface area. The wettability and surface charge of magnetic materials are significant factors in oily wastewater treatment . However, the specific influence of surface charge on the demulsification performance has not been rigorously investigated. Herein, a series of MNPs coated by dimethyl-diallyl-ammonium chloride (PDDA) and fulvic acid (FA) (Fe 3 O 4 /FA/PDDA) with different surface positive charges were synthesized by adjusting the PDDA concentrations and applied in demulsification of hexadecane-water micro-emulsion. The oil-water separation efficiency ( Es ) was enhanced gradually with increasing the surface positive charge of demulsifiers. Derjaguin-Landau-Verwey-Overbeek (DLVO) theory confirmed that with increasing surface positive potential, the electrostatic attraction between demulsifiers and oil droplets increased, and thus, Es increased. In addition, the superior Es of Fe 3 O 4 /FA MNPs for hexadecyl trimethyl ammonium bromide (CTAB)-stabilized micro-emulsions and Fe 3 O 4 /FA/PDDA MNPs for sodium dodecyl sulfate (SDS)-stabilized micro-emulsions further confirmed that electrostatic force was critical in demulsification. The high positively charged Fe 3 O 4 /FA/PDDA MNPs can be used as an efficient and recyclable demulsifier for hexadecane-water micro-emulsion. This study provides a theoretical basis for designing demulsifiers.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2023
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IF 13.6
Chao Fan,Yiping Liu,Songlin Fan,Zirong Liang,Wuxiang Zhang,Yanjuan Zhang,Tao Gan,Huayu Hu,Zuqiang Huang,Yuben Qin
The treatment of emulsion wastewater poses significant challenges. In this study, a novel porous material, namely esterified bagasse/poly(N, N-dimethylacrylamide)/sodium alginate (SBS/PDMAA/Alg) aerogel , was developed for efficient demulsification and oil recovery. By grafting a poly(N-isopropylacrylamide) (PNIPAM) brush onto the SBS/PDMAA/Alg skeleton through free radical polymerization, the resulting aerogel exhibits both surface charge and a molecular brush structure. The aerogel demonstrates remarkable demulsification efficiency for cationic surfactant-stabilized emulsions at various concentrations, achieving a demulsification efficiency of 95.6% even at an oil content of 100 g L −1 . Furthermore, the molecular brush structure extends the application range of the aerogel, enabling a demulsification efficiency of 98.3% for anionic and non-ionic surfactant-stabilized emulsions. The interpenetrating polymer network (IPN) structure formed by SBS, PDMAA, and alginate enhances the mechanical stability of the aerogel, enabling a demulsification efficiency of 91.3% even after 20 repeated cycles. The demulsification ability of the composite aerogel is attributed to its surface charge, high interfacial activity, and unique brush-like structure. A demulsification mechanism based on the synergistic effect of surface charge and molecular brush is proposed to elucidate the efficient demulsification process.
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
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2022
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IF 13.4
Yang Zhao,Yuna Gu,Guandao Gao
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 × 10 7 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.
研究领域:
环境科学
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材料科学
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废水处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF FLUORINE CHEMISTRY
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2021
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IF 2.05
Nianze Song,Xin Huang,Yifei Li,Kaokao Zhang,Chaihui Wei,Jian Zhang,Yue Zhang
ABSTRACT To deal with the demulsification of emulsion stabilized by naphthenic compounds, a series of multibranched–linear–multibranched (MLM) copolymer were designed and synthesized. The hydrophilic core with MLM structure is constructed by anionic ring-opening multibranching polymerization (ROMBP) of glycidol with poly (ethylene glycol). The amphophobic arms are grafted by atom transfer radical polymerization (ATRP) of 2, 2, 2-trifluoroethyl methacrylate (TFEMA). The demulsification performance of the MLM copolymer in n-octane/water emulsion stabilized by naphthenic acids (NAs) and sodium naphthenates (Na-NAs) were evaluated. The influences of copolymer dosage, temperature and Na-NAs/NAs ratio on the demulsification efficiency were investigated in detail. Compared with the blank sample settled for 90 min, the fluorinated MLM copolymer with medium HLB value promoted the demulsification efficiency from 50% to 92%. By analyzing the correlation between the polymer structure and demulsification performance, it can be considered that the PEG segment improved the low solubility of the fluorinated copolymer caused by the solvophobic nature of fluorinated groups. The amphophobic effect of the fluorinated group not only accelerates the diffusion process of polymer molecules from the bulk to the interface, but also reduces the rigidity of the interface film by repelling the original interface active material, and produces effective demulsification.
研究领域:
化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）