RSC Advances
·
2018
·Vol. 8
·期 46
·26318-26324
·
IF 2.936
Xianbin Huang,Jinsheng Sun,Kaihe Lv,Jingping Liu,Haokun Shen
This study presents an alternative method to enhance the emulsion stability of oil based drilling fluids (OBMs). Modified dimer acid (MDA) was synthesized with a molecular structure having two hydrophilic heads and two hydrophobic tails. Theoretically, the adsorption of MDA on an oil–water interface makes it possible to increase hydrogen bonding between water droplets and form three dimensional networks which benefit emulsion stability. The influence of MDA on the stability of base emulsions was studied by visual observation. Then the stabilization mechanism of MDA was analyzed from the micro and macro points of view by morphology study using a cryo-scanning electron microscope (cryo-SEM) and rheological measurements including viscosity vs. shear rates, zero-shear viscosity (η0), and creep and recovery tests. Experimental results showed that a substantial improvement in emulsion stability was visually observed when the MDA concentration was 2 g L−1. From cryo-SEM observation, a honeycomb structure was observed in the emulsion containing 2 g L−1 MDA, which can provide a physical barrier to restrain the movement of water droplets. In comparison with the rheological behaviors of the emulsion without MDA, a remarkably larger zero-shear viscosity, a solid-like behavior and a greater elasticity were observed when 2 g L−1 MDA was present. Finally, the application in OBMs shows that MDA can largely enhance electrical stability (ES) and reduce the filtration volume. The method proposed in the paper could be used to enhance the stability of w/o emulsions in a variety of fields.
研究领域:
化学工程
·
石油工程
✓ 已验证
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Shikun Tong,Pengfei Li,Fengjun Lv,Zhiyuan Wang,Weiqi Fu,Jianbo Zhang,Litao Chen,Xuerui Wang
Clarifying the effect of wax on hydrate formation and dissociation are important for the safe and high-efficient development of deep-water oil and gas fields. In this study, a series of experiments on the effect of wax on hydrate formation and dissociation in water-in-oil emulsions were systematically studied based on the variation analysis of temperature, pressure, torque, oil–water interface area morphology and water droplet size in emulsions. Microscopic images reveal that wax crystals form shell barriers on the oil–water interface, which increases transfer resistance, and the particle focused beam reflectance illustrates that the wax crystals decrease the water droplet size, which increases the oil–water interface area in emulsions. With increasing wax concentration, the hydrate induction time and growth rate show a bimodal shape because of the dual regulation of wax in emulsions, involving the inhibition effect of the transfer barrier layer and the promotion effect of the increasing water–oil interface area. The inhibition effect on hydrate formation was dominant when the wax concentration exceeds 6 wt%, resulting in a rapid decrease in both the growth rate and conversion ratio with increasing wax concentration. Compared with the bimodal shape of hydrate formation, the inhibition effect of wax on hydrate dissociation is the dominant regulation factor. The duration of complete hydrate dissociation by depressurization increased linearly with the increasing wax concentration, which increased the operation difficulty of hydrate plug removal. These experimental results provide valuable references for hydrate risk assessment and optimization of the project design of flow assurance for deep-water oil and gas fields.
研究领域:
石油工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2018
·
IF 4.946
Leqi Cui,Jing Fan,Yifei Sun,Zhenbao Zhu,Jianhua Yi
Salts reduction/substitution have gained a lot interest from food industry since the US Food and Drug Administration (FDA) has issued a draft guidance for salt reduction. However how changes of salts in food formulation could influence lipid oxidation is still not fully understood. Using oil-in-water emulsions stabilized by a natural emulsifier – lecithin at pH 7.0 as a model system, this study evaluated how salts affect the physical parameters of the emulsion, the chelating activity of lecithin and thus the lipid oxidation of these emulsions. Results showed that salts increased the particle size, the negative charge of the oil droplets, and the amount of iron chelated by lecithin. Lipid oxidation lag phases were shortened by addition of salts, by 1 day and 2 days for lipid hydroperoxides and thiobarbituric acid reactive substances measurements respectively. These results provide some new insights on the mechanisms of how salts could affect the lipid oxidation of food emulsions.
研究领域:
食品科学
·
生物化学
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产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2013
·Vol. 1
·期 17
·5353-5360
·
IF 0
Chunfeng Ma,Xiaobo Bi,To Ngai,Guangzhao Zhang
Well-defined polyurethane (PU)-based grafted copolymers with poly(2-(dimethylamino)ethyl methacrylate) (PDEM) side chains were prepared by a combination of radical polymerization and condensation reaction. They can self-assemble in water to form nanoparticles with PU as the core and hydrophilic PDEM chains as the shell. Tuning the pH value of the solutions allowed these nanoparticles to stabilize either oil-in-water (O/W) or water-in-oil (W/O) Pickering emulsions. Stable O/W emulsions were obtained with PU-based nanoparticles in the pH 3–5 or pH 11–12 range due to their better affinity to the aqueous phase. In contrast, changing the pH value to the range of 8–9 significantly changed the stabilizing behavior of the nanoparticles, leading to the formation of stable W/O emulsions. Additionally, the effect of oil polarity on the emulsification behavior of the PU-based nanoparticles was investigated. For highly non-polar oil like n-hexane, only O/W emulsions were generated and the resulting emulsions showed no response to pH change.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
·
2023
·
IF 2.2
Kun Li,Xiaoxiao Li,Anqi Ming,Yiming Guo,Jun Sun,Hua Wang,Jianjun Ding,Xingyou Tian,Yuxiang Cao,Yuwei Lin
The properties of Pickering emulsions is affected by many factors, one of the most typical of which is the ionic environment. Existing studies have mainly focused on the effect of ions in the continuous phase on oil-in-water Pickering emulsions, and usually only single species of ions are studied. The water-in-oil Pickering emulsions are commonly used to encapsulate a variety of water-soluble functional substances, which often contain various of ions. Therefore, it is necessary to study the effect of ions in the internal phase on the properties of inverse Pickering emulsions. The inverse Pickering emulsions with an average droplet size of 100 μm were prepared using hydrophobized calcium carbonate particles. Subsequently, Na+ and Ca2+ were introduced into the internal phase to investigate their effects on the emulsion. The results show that the presence of Na+ can aggravate droplet coalescence, and Ca2+ can cause severe damage to the emulsions and even lead to phase inversion. It was speculated that Na+ can weaken the surface charge of particles by compressing the electric double layer, resulting in lower electrostatic repulsion between particles, thus changing the dispersion state of the particles and ultimately affecting the properties of the emulsion. And Ca2+ can combine with and release stearate from the particle surface through chemical reactions, thus changing the wettability of the particles and resulting in breaking and phase inversion of the emulsions. The present work is informative for the setting of the phase composition and the prediction of stability during the application of inverse Pickering emulsions.
研究领域:
化学
·
材料科学
·
食品科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
·
2025
·
IF 1.9
Ju Huang,Linyu Li,Ying Zhu,Yan Xiong,Peng Shi,Shuai Liu,Ming Duan
Study on the stability of oil-in-water (O/W) emulsions is significant for breaking O/W emulsions, which is a key problem in oilfield wastewater treatment. So far, the traditional methods for exploring the stability of emulsions are mostly bulk measurements. Here, we report directly observing the sticking propability of pairs of emulsion droplets by optical tweezers to investigate the stability of O/W emulsions at the microscale. It was confirmed that resins in the oil phase and various types of surfactants in the aqueous phase are all beneficial for the stability of O/W emulsions. Besides, the conventional bulk measurements of Zeta potential and interfacial tension were also carried out to study the influence of the above species on the stability of O/W emulsions. The resultant data are well consistent with those obtained from the optical tweezer method (OTM). Our results show that optical tweezer is a new and reliable approach to evaluate the stability of oil-in-water emulsions and it opens up a bright road for exploring the stability of emulsions at microscale.
研究领域:
化学工程
·
界面科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Applied Sciences-Basel
·
2019
·Vol. 9
·期 5
·1008
·
IF 2.217
Gaohong Zuo,Yingchao Du,Lianqi Wei,Bo Yu,Shufeng Ye,Xiaomeng Zhang,Hongshun Hao
Emulsified pickling waste liquid, derived from cleaning oily hardware, cause serious environmental and ecological issues. In this work, a series of grafted (3-aminopropyl)triethoxysilane (APTES) TiO2pillared montmorillonite (Mt), Ti-Mt-APTES, are prepared and characterized for their assessment in demulsification of acidic oil-in-water emulsion. After titanium hydrate is introduced through ion exchange, montmorillonite is modified by hydrophobic groups coming from APTES. The Ti-Mt-APTES in acidic oil-in-water emulsion demulsification performance and mechanism are studied. Results show that the prepared Ti-Mt-APTES has favorable demulsification performance. The Ti-Mt-APTES demulsification efficiency (ED) increased to an upper limit value when the mass ratio of APTES to the prepared TiO2pillared montmorillonite (Ti-Mt) (RA/M) was 0.10 g/g, and the 5 h is the optimal continuous stirring time for breaking the acidic oil-in-water emulsion by Ti-Mt-APTES. The EDincreased to 94.8% when 2.5 g/L of Ti-Mt-APTES is added into the acidic oil-in-water emulsion after 5 h. An examination of the demulsification mechanism revealed that amphiphilicity and electrostatic interaction both played vital roles in oil-in-water separation. It is demonstrated that Ti-Mt-APTES is a promising, economical demulsifier for the efficient treatment of acidic oil-in-water emulsions.Keywords:modified montmorillonite;oil-in-water emulsion;acidic demulsification;silane couple grafting
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Chemical Engineering and Processing-Process Intensification
·
2017
·
IF 2.234
Xiaoming Luo,Juhang Cao,Haipeng Yan,Haiyang Gong,Haoran Yin,Limin He
The separation characteristics of W/O emulsion were investigated under ultrasonic standing wave field in this paper. The effects of the irradiation time, acoustic intensity, frequency, oil viscosity, and oil-water interfacial tension on the separation characteristics of emulsion were studied in details. It was proved that there existed an optimal irradiation time, acoustic intensity and oil-water interfacial tension to achieve the maximum separation efficiency in ultrasonic treatment process. Excessive long irradiation time had little effect on improving the dehydration rate of emulsion but rather increased unnecessary processing time. Excessive high acoustic intensity caused the occurrence of acoustic cavitation phenomenon. The acoustic cavitation would cause the aggregated droplets to be dispersed by oscillating bubbles or even emulsified again by high speed micro jets. The acoustic cavitation threshold is effectively and accurately obtained by a spectral analysis method. The micro acoustic streaming which resulted from the attenuation of acoustic energy occurred with the increase of frequency. It sheared the aggregated droplets, destroyed the stable droplets banding and reduced the separation efficiency of emulsion. The excess surfactant adsorbed on the oil-water interface resulted in the increase of the interfacial film strength, which hindered the coalescence process of droplets and reduced the separation efficiency.
研究领域:
化学工程
·
声学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
LANGMUIR
·
2021
·
IF 3.882
Wenjing Ma,Shanshan Dai,Peiyao Zhu,Ru Zhou,Hongsheng Lu
Two kinds of water-soluble tertiary amines (TAs), triethylamine (TEA, monoamine), and tetramethyltrimethylenediamine (TMA, diamine) were introduced into a NaOA stable oil–water (O/W) emulsion, respectively, and their dual reactivity to carbon dioxide was studied. TA was converted into bicarbonate after bubbling of CO2, which induced the increase of ionic strength of the aqueous phase, and formed ion pair with NaOA through electrostatic interaction. NaOA itself can also be protonated into oleic acid, which can be reverently deprotonated by alternating bubbles of CO2 at 25 °C and N2 at 50 °C, thus affecting the stability and demulsification process of the emulsion. In order to demonstrate TA’s and NaOA’s synergistic effect on CO2 responsiveness, gas chromatography–mass spectrometry, ζ potential, electrical conductivity, pH value, 1H nuclear magnetic resonance, morphological evolution, and interfacial tension were used to study the contributions of the single component and two components of NaOA, TEA, and TMA to emulsion stability and CO2 responsiveness, respectively. Combined with the composition distribution under different pH conditions, it was further proved that TAs had an effect on the stability and CO2 responsiveness of the NaOA emulsion.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
LANGMUIR
·
2024
·
IF 3.7
Haozhe Yi,Taotao Fu,Daofan Ma,Chunying Zhu,Youguang Ma
The droplet transfer across an interface in a microchannel is extensively utilized in diverse fields; however, it is challenging to drive droplets to penetrate the interface at such a small scale. In this study, a novel flow pattern of droplet transfer is observed and the mechanism is investigated; accordingly, an accurate prediction equation for determining the critical condition of droplet transfer is proposed. Meanwhile, the liquid film entrainment is also observed, which leads to the formation of an oil-in-water-in-water system. This study serves as a valuable reference for further studies on the mechanism of droplet transfer and provides practical guidance for its industrial application.
研究领域:
化学工程
·
微流控技术
·
界面科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2021
·Vol. 28
·期 39
·55454-55464
·
IF 4.223
Shen Liwei,Hu Wenxiang,Lei Zhiyun,Peng Jianguo,Zhu Enxiong,Zhang Xuanwei,Yang Ming,Feng Xuening,Yang Ying,Mi Yuanzhu
In current work, GO@SiO 2 nanocomposite was prepared by coating nanoscale silica onto graphene oxide (GO). GO@SiO 2 was characterized with scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (IF-IR). Additionally, the demulsifying performance of GO@SiO 2 was investigated by bottle test. The results showed that GO@SiO 2 had a good demulsifying performance in both oil-in-water (O/W) and water-in-oil (W/O) emulsions. When the concentration of GO@SiO 2 was 200 ppm in the O/W emulsion, the optimal light transmittance of aqueous phase (LTA) and corresponding oil removal rate (ORR) at room temperature could reach 86.9% and 99.48%, respectively. Also, GO@SiO 2 had an excellent salt tolerance under acidic condition. Furthermore, GO@SiO 2 also could demulsify the W/O emulsion, and the efficiency at 70 °C could reach 80.5% when the concentration was 400 ppm.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2015
·Vol. 40
·期 1
·589-595
·
IF 3.086
Hui Yang,Yuan Xie,Guisong Hao,Weiwei Cai,Xingzhong Guo
Porous alumina (Al2O3) microspheres with incontinuous multicavities have been successfully prepared via an oil-in-water (O/W) emulsion method accompanied by a sol–gel process in the presence of polyvinylpyrrolidone (PVP), sorbitan monooleate (Span 80) and ethyl acetoacetate (EAA). The introduction of PVP as a phase separation inducer into the oil phase of the O/W emulsion leads to the formation of incontinuous multicavities inside the microspheres, and the size of the cavities enlarges with the increase of the amount of PVP, while has no significant influence on the surface morphology and particle size distribution of the microspheres. EAA works as a chelating agent to ensure a spherical shape, and Span 80 acts as a stabilizer to preserve a smooth surface. An appropriate amount of PVP, EAA and Span 80 allow the formation of porous alumina microspheres with incontinuous multicavities. A preliminary mechanism based on phase separation for the structural evolution of alumina porous microspheres with multicavities is suggested. The spheres after heat treatment experience a phase transformation process in the following sequence: amorphous → γ-Al2O3 → α-Al2O3.
研究领域:
材料科学
·
化学工程
✓ 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）