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Xiao F, Li K, Wang W, Ge Y, Yu Z, Peng Z, Liu Y, Gong J. Effect of Oil-Soluble/Water-Soluble Surfactants on the Stability of Water-in-Oil Systems, an Atomic Force Microscopy Study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:3862-3870. [PMID: 36908066 DOI: 10.1021/acs.langmuir.2c02992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The stabilization mechanism of water-in-oil (W/O) emulsions has been studied by measuring the interactions between two water droplets in n-tetradecane using atomic force microscopy. The effects of water-soluble surfactants (SDS/CTAB/Tween 80), an oil-soluble surfactant (Span 20), and the coexistence of the water and oil-soluble surfactants on the stability of water droplets in oil were investigated separately. It is found that the addition of oil-soluble surfactants (Span 20) prevents the coalescence of water droplets in oil. To discuss the role of an oil-soluble surfactant, we analyzed the force curve by applying the theoretical model. The results demonstrate that the oil-soluble surfactant (Span 20) stabilizes dispersed droplets by adsorbing onto the interface and forming a relatively tighter layer with the increase in surfactant concentration, which hinders film rupture. This behavior of the surfactant could also be properly characterized by steric hindrance. A further step was taken by introducing another water-soluble surfactant. It is found that the addition of either SDS or CTAB into the water phase is futile in inducing droplet coalescence in the presence of Span 20. In contrast, Tween 80 was found to be effective in destabilizing water droplets, which could be due to the competitive adsorption between Tween 80 and Span 20 at the interface. By characterizing the interfacial adsorption of Tween 80 and Span 20 with a theoretical adsorption isotherm model, the result indicates that interface replacement would result in a loose adsorption layer that is insufficient to hinder droplet coalescence. Our study provides an intriguing understanding of the role of surfactants in the stabilization and destabilization of water-in-oil emulsions.
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Affiliation(s)
- Fan Xiao
- Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, MOE Key Laboratory of Petroleum Engineering, State Key Laboratory of Natural Gas Hydrates, China University of Petroleum, Beijing. No. 18 Fuxue Road, Changping District, 102249 Beijing, P. R. China
| | - Kai Li
- Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, MOE Key Laboratory of Petroleum Engineering, State Key Laboratory of Natural Gas Hydrates, China University of Petroleum, Beijing. No. 18 Fuxue Road, Changping District, 102249 Beijing, P. R. China
- School of Petrochemical Engineering, Lanzhou University of Technology, No. 287, Langongping Road, Qilihe District, Lanzhou, Gansu 730050, P. R. China
| | - Wei Wang
- Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, MOE Key Laboratory of Petroleum Engineering, State Key Laboratory of Natural Gas Hydrates, China University of Petroleum, Beijing. No. 18 Fuxue Road, Changping District, 102249 Beijing, P. R. China
| | - Yuntong Ge
- Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, MOE Key Laboratory of Petroleum Engineering, State Key Laboratory of Natural Gas Hydrates, China University of Petroleum, Beijing. No. 18 Fuxue Road, Changping District, 102249 Beijing, P. R. China
| | - Zhipeng Yu
- Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, MOE Key Laboratory of Petroleum Engineering, State Key Laboratory of Natural Gas Hydrates, China University of Petroleum, Beijing. No. 18 Fuxue Road, Changping District, 102249 Beijing, P. R. China
| | - Zeheng Peng
- Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, MOE Key Laboratory of Petroleum Engineering, State Key Laboratory of Natural Gas Hydrates, China University of Petroleum, Beijing. No. 18 Fuxue Road, Changping District, 102249 Beijing, P. R. China
| | - Yingming Liu
- Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, MOE Key Laboratory of Petroleum Engineering, State Key Laboratory of Natural Gas Hydrates, China University of Petroleum, Beijing. No. 18 Fuxue Road, Changping District, 102249 Beijing, P. R. China
| | - Jing Gong
- Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, MOE Key Laboratory of Petroleum Engineering, State Key Laboratory of Natural Gas Hydrates, China University of Petroleum, Beijing. No. 18 Fuxue Road, Changping District, 102249 Beijing, P. R. China
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Lan W, Cai D, Hu X, Jing S, Li S. Determination of dynamic interactions of droplets in continuous fluids using droplet probe. J Colloid Interface Sci 2021; 605:91-100. [PMID: 34311316 DOI: 10.1016/j.jcis.2021.07.073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 07/09/2021] [Accepted: 07/10/2021] [Indexed: 10/20/2022]
Abstract
HYPOTHESIS Interactions between droplets are of fundamental importance for understanding phenomena involving droplet collision and coalescence that determine multiphase flow behavior. The quantitative understanding of these interactions is essential for the manipulation and control of emulsions or complex fluids. The existing methods for interaction force determination are typically based on expensive mechanical probes and fine distance control. Therefore, further development of new techniques for interaction force determination is expected to be beneficial for research on surface force. EXPERIMENTS In this study, droplet deformation during the interaction between two droplets was captured and analyzed to determine the interaction force. The approach speed of the two droplets was controlled by the injection rate of the fluid. The dynamic interaction force between two tetradecane droplets in various aqueous solutions was determined using the newly developed method, and the effects of two-phase physical properties and operating conditions on the measurement errors were investigated. FINDINGS The droplet profile deformation was first applied as a probe to detect the interaction force. The measurement results were in good agreement with those obtained using the precise weighing sensor of a commercial interfacial tensiometer (K100, Kruss, Germany). The newly developed method was reliable, simple, and did not require the use of expensive devices. Furthermore, droplet deformability was found to be the key parameter in determining the total interaction force between the droplets.
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Affiliation(s)
- Wenjie Lan
- State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China.
| | - Dizong Cai
- State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China
| | - Xiaojie Hu
- State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China
| | - Shan Jing
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Shaowei Li
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China.
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Li K, Wang W, Xiao F, Ge Y, Jin H, Yu Z, Gong J, Gao W, Peng Z. Atomic Force Microscopy Study of Non-DLVO Interactions between Drops and Bubbles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:6830-6837. [PMID: 34043914 DOI: 10.1021/acs.langmuir.1c00937] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The heterointeraction between liquid drops and air bubbles dispersed in another immiscible liquid is studied with the application of the atomic force microscopy (AFM) probe techniques. The tetradecane drops and air bubbles readily coalescence to form a lens-like structure in 100 mM sodium chloride aqueous solution, demonstrating strong hydrophobic (HB) attraction. The interaction range and strength of this hydrophobic attraction between oil drops and air bubbles is investigated by fine control of electrical double layer thicknesses related to specific electrolyte concentrations, and a midrange term in combination with a short-range term is found to present a proper characterization of this hydrophobic attraction. A further step is taken by introducing a triblock copolymer (Pluronic F68) into the aqueous solution, with results indicating that a relatively long-range steric hindrance (SH) furnished by a polymer "brush" surmounts the hydrophobic attraction. Finally, the interaction between a water drop and an air bubble in tetradecane is also measured as a comparison. The repelling action between a hydrophobic body (air bubble) and water drop indicates a strong repulsion. The present results show an interesting understanding of hydrophobic interactions between drops and bubbles, which is of potential application in controlling dispersion stability.
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Affiliation(s)
- Kai Li
- Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, State Key Laboratory of Natural Gas Hydrates, MOE Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing, No. 18 Fuxue Road, Changping District, 102249 Beijing, P. R. China
| | - Wei Wang
- Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, State Key Laboratory of Natural Gas Hydrates, MOE Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing, No. 18 Fuxue Road, Changping District, 102249 Beijing, P. R. China
| | - Fan Xiao
- Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, State Key Laboratory of Natural Gas Hydrates, MOE Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing, No. 18 Fuxue Road, Changping District, 102249 Beijing, P. R. China
| | - Yuntong Ge
- Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, State Key Laboratory of Natural Gas Hydrates, MOE Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing, No. 18 Fuxue Road, Changping District, 102249 Beijing, P. R. China
| | - Hang Jin
- Tianjin Research Institute for Water Transport Engineering, Key Laboratory of Environmental Protection Technology on Water Transport, Ministry of Transport, No. 2618 Xingang Second Road, Binhai New District, 300456 Tianjin, P. R. China
| | - Zhipeng Yu
- Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, State Key Laboratory of Natural Gas Hydrates, MOE Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing, No. 18 Fuxue Road, Changping District, 102249 Beijing, P. R. China
| | - Jing Gong
- Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, State Key Laboratory of Natural Gas Hydrates, MOE Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing, No. 18 Fuxue Road, Changping District, 102249 Beijing, P. R. China
| | - Weiwei Gao
- Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, State Key Laboratory of Natural Gas Hydrates, MOE Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing, No. 18 Fuxue Road, Changping District, 102249 Beijing, P. R. China
| | - Zeheng Peng
- Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, State Key Laboratory of Natural Gas Hydrates, MOE Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing, No. 18 Fuxue Road, Changping District, 102249 Beijing, P. R. China
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Chen A, Liu X, Wu Y, Luo G, Xu JH. Interactions between CO 2-Responsive Switchable Emulsion Droplets Determined by Using Optical Tweezers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:4600-4606. [PMID: 32299211 DOI: 10.1021/acs.langmuir.0c00203] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
CO2-responsive switchable emulsions have been of great interest in some industrial processes where the stability of the emulsion is only required temporarily, such as oil transport, drug delivery, and fossil fuel production. The good understanding of the stability and instability mechanism is vital to the switchable behavior between emulsification and demulsification. Herein, a novel approach was developed to determine the interactions between two switchable emulsion droplets directly by a dual-laser optical tweezers instrument. The repulsive force between a couple of tetradecane droplets occurs to increase progressively with the increasing concentration of switchable surfactant in solutions. However, the repulsive force appears to decrease progressively in turn when the switchable surfactant concentration is far higher than the critical micelle concentration (CMC). Moreover, the depletion effect starts to emerge in the higher surfactant concentration which is attributed to the switchable surfactant micelles generated in solutions. In addition, according to the measurements of interaction forces, a mechanism of the switchable behavior is well proposed, which is established by the principle of self-assembly/detachment of the switchable surfactant, resulting in the weakening and re-enhancing of the electrostatic double-layer (EDL) repulsive forces between tetradecane droplets, upon selective introduction and removal of CO2. Based on this work, a novel perspective was provided to study the switchable emulsion, which can contribute instructive messages for the understanding of stability and instability mechanisms of switchable emulsions.
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Affiliation(s)
- An Chen
- The State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Xueyan Liu
- The State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Yuxin Wu
- The State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Guangsheng Luo
- The State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Jian-Hong Xu
- The State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
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Chen A, Li S, Xu J. A novel approach to study the interactions between polymeric stabilized micron-sized oil droplets by optical tweezers. Chin J Chem Eng 2020. [DOI: 10.1016/j.cjche.2019.12.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Kim M, Heinrich F, Haugstad G, Yu G, Yuan G, Satija SK, Zhang W, Seo HS, Metzger JM, Azarin SM, Lodge TP, Hackel BJ, Bates FS. Spatial Distribution of PEO-PPO-PEO Block Copolymer and PEO Homopolymer in Lipid Bilayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:3393-3403. [PMID: 32216370 PMCID: PMC8097911 DOI: 10.1021/acs.langmuir.9b03208] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Maintaining the integrity of cell membranes is indispensable for cellular viability. Poloxamer 188 (P188), a poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymer with a number-average molecular weight of 8700 g/mol and containing 80% by mass PEO, protects cell membranes from various external injuries and has the potential to be used as a therapeutic agent in diverse applications. The membrane protection mechanism associated with P188 is intimately connected with how this block copolymer interacts with the lipid bilayer, the main component of a cell membrane. Here, we report the distribution of P188 in a model lipid bilayer comprising 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (POPC) using neutron reflectivity (NR) and atomic force microscopy (AFM). We also investigated the association of a PEO homopolymer (PEO8.4K; Mn = 8400 g/mol) that does not protect living cell membranes. These experiments were conducted following incubation of a 4.5 mmol/L polymer solution in a buffer that mimics physiological conditions with supported POPC bilayer membranes followed by washing with the aqueous medium. In contrast to previous reports, which dealt with P188 and PEO in salt-free solutions, both P188 and PEO8.4K penetrate into the inner portion of the lipid bilayer as revealed by NR, with approximately 30% by volume occupancy across the membrane without loss of bilayer structural integrity. These results indicate that PEO is the chemical moiety that principally drives P188 binding to bilayer membranes. No defects or phase-separated domains were observed in either P188- or PEO8.4K-incubated lipid bilayers when examined by AFM, indicating that polymer chains mingle homogeneously with lipid molecules in the bilayer. Remarkably, the breakthrough force required for penetration of the AFM tip through the bilayer membrane is unaffected by the presence of the large amount of P188 and PEO8.4K.
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Affiliation(s)
- Mihee Kim
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Frank Heinrich
- Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
- National Institute of Standards and Technology Center for Neutron Research, Gaithersburg, Maryland 20899, United States
| | - Greg Haugstad
- Characterization Facility, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Guichuan Yu
- Informatics Institute, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Guangcui Yuan
- National Institute of Standards and Technology Center for Neutron Research, Gaithersburg, Maryland 20899, United States
- Department of Physics, Georgetown University, Washington, D.C. 20057, United States
| | - Sushil K Satija
- National Institute of Standards and Technology Center for Neutron Research, Gaithersburg, Maryland 20899, United States
| | - Wenjia Zhang
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Hannah S Seo
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Joseph M Metzger
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, United States
| | - Samira M Azarin
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Timothy P Lodge
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Benjamin J Hackel
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Frank S Bates
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
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Zaibudeen A, Philip J. Adsorption of bovine serum albumin at oil-water interface in the presence of polyelectrolytes and nature of interaction forces. Colloids Surf A Physicochem Eng Asp 2019. [DOI: 10.1016/j.colsurfa.2019.01.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Liu M, Cao XL, Zhu YW, Guo ZY, Zhang L, Zhang L, Zhao S. The effect of demulsifier on the stability of liquid droplets: A study of micro-force balance. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2018.11.094] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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