LANGMUIR
·
2019
·
IF 3.683
Shuai Liu,Yue Hu,Jing Xia,Shenwen Fang,Ming Duan
Dual-trap optical tweezers have been used to directly measure the interaction forces between two silica particles upon controlling the concentration of the ionic surfactant sodium dodecylbenzenesulfonate (SDBS). By capturing two silica particles in one spot optical trap and one linear optical trap and controlling the linear trap to bring one particle to approach another sufficiently closer, the interaction forces between these two particles can be measured as the separation distance changes. Results showed that with increasing concentrations of SDBS, the interaction force between the two silica particles emerges at closer surface distance between two silica particles. Only repulsive force exists between silica particles below the critical micelle concentration (cmc) of SDBS and it could be well-fitted using the classical Derjaguin–Landau–Verwey–Overbeek (DLVO) theory. However, the depletion attraction force appears above the cmc of SDBS which is induced by the generation of SDBS micelles. By in situ measurement of the interaction force between two silica particles in the presence of different concentrations of SDBS, the depletion force can be quantitatively calculated.
研究领域:
胶体科学
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界面化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
·
2024
·
IF 1.9
Jie He,Ming Duan,Shouwei Zhou,Liqiang Zhao,Zhifeng Luo,Shenwen Fang
The widespread use of polymer flooding has resulted in a large number of produced liquids consisting of crude oil emulsions and oily wastewater. Efficient flocculants are required to treat these produced liquids till the oily wastewater satisfies the requirements for reinjection formation in order to maintain the regular manufacturing process. In this work, an unsaturated polyether macromonomer (PEP-30) was prepared by ring-opening polymerization using isobutenol as a starting material. Subsequently, a novel flocculant (PMAP) was obtained by copolymerization of dimethylamino propylmethacrylamide (DMAPMA) and PEP-30. For the produced liquids with different crude oil emulsion content, the oil removal rate of PMAP at a dosage of 150 mg/L was more than 75%, and the oil removal rate and versatility were better than those of conventional cationic flocculants. Furthermore, the findings of the flocculation mechanism investigation demonstrated that PMAP had a low interfacial elastic modulus and a large interfacial adsorption mass. Specifically, the optical tweezers were used to detect the interaction force between oil droplets. PMAP effectively strengthened the attraction between oil droplets, extending their duration in contact during flocculation and promoting their coalescence.
研究领域:
化学工程
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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
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
ANALYTICAL CHEMISTRY
·
2016
·
IF 5.886
Cheng-Yu Li,Di Cao,Ya-Feng Kang,Yi Lin,Ran Cui,Dai-Wen Pang,Hong-Wu Tang
We present an analytical platform by combining near-infrared optical tweezers with two-photon excitation for fluorescence detection of H5N1 virus gene sequences. A heterogeneous enrichment strategy, which involved polystyrene (PS) microsphere and quantum dots (QDs), was adopted. The final hybrid-conjugate microspheres were prepared by a facile one-step hybridization procedure by using PS microspheres capturing target DNA and QDs tagging, respectively. Quantitative detection was achieved by the optical tweezers setup with a low-cost 1064 nm nanosecond pulse laser for both optical trapping and two-photon excitation for the same hybrid-conjugate microsphere. The detection limits for both neuraminidase (NA) gene sequences and hemagglutinin (HA) gene sequences are 16–19 pM with good selectivity for one-base mismatch, which is approximately 1 order of magnitude lower than the most existing fluorescence-based analysis method. Besides, because of the fact that only signal from the trapped particle is detected upon two-photon excitation, this approach showed extremely low background in fluorescence detection and was successfully applied to directly detect target DNA in human whole serum without any separation steps and the corresponding results are very close to that in buffer solution, indicating the strong anti-interference ability of this method. Therefore, it can be expected to be an emerging alternative for straightforward detecting target species in complex samples with a simple procedure and high-throughput.
研究领域:
生物技术
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分子生物学
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光学分析
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
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2019
·
IF 1.911
An Chen,Shaowei Li,Jianhong Xu
The well understanding of interaction forces between single dispersed droplets is crucial to the understanding of emulsion stabilization mechanism. Recently, many studies have reported the direct quantitative measurements of interaction forces between 20-200 μm single droplet coated polymers by atomic force microscope (AFM). These studies have revealed many important results about the relationship of the interaction forces and the droplet deformation. However, these studies of the quantitative relationship between the measured interaction forces and the separation distance of the front end of the droplet have rarely been reported. Optical tweezer instrument can make it possible to establish the quantitative relationship between the measured force and the separation distance of the front end of the droplet, which will make better understanding of the interaction mechanisms between droplets. Due to the differences of the measuring mechanism between atomic force microscopy (AFM) and optical tweezers, the theory model of AFM measurements cannot be fitted with the force measurement by optical tweezers. We have made an exhaustive comparison of the measuring differences between AFM and optical tweezer instrument in this work. Moreover, we built a numerical model to derive the repulsive pressure through the measured force curve in order to quantify the measured force of two micron-sized oil droplet coated polymers by optical tweezers. Furthermore, the novel method can be extended to other micron-sized emulsion systems, and these findings will be a vital progress on quantitative force measurements between micron-sized droplets.
研究领域:
化学工程
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物理学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2018
·
IF 3.306
An Chen,Shao-Wei Li,Dian Jing,Jian-Hong Xu
Non-ionic surfactants are widely used in many industrial applications such as detergents, oil recovery, and mineral flotation techniques. Non-ionic surfactants readily adsorb onto the oil-water interface, although they cannot dissociate in solutions like ionic surfactants can. Nonetheless, the electrostatic double-layer (EDL) repulsive force between oil drops coated with the non-ionic surfactant can still provide stability against coalescence. In this work, the interaction forces between two tetradecane drops with diameter of 6.5 µm were measured in the presence of the non-ionic fluorocarbon-based surfactant FS-30 in various salt solutions using optical tweezers. The measured force curves were consistent with the presence of a surface charge, even though the surfactant was non-ionic in nature. The results clearly show that the EDL repulsive force is gradually screened with increasing salt concentration. It was also found that the EDL repulsive force was significantly screened in the divalent cation salt solutions (Ca 2+ , Ba 2+ ) in comparison to in the monovalent cation salt solutions (Na + ). In addition, the absolute value of the measured zeta potential ( − ξ ) of emulsified tetradecane drops gradually decreased with increasing FS-30 concentration. In all experimental processes, the emulsified tetradecane drops coated with FS-30 were stable against coalescence. These findings have significant implications for the stability of emulsions used in the food, cosmetic, and detergent industries.
研究领域:
化学工程
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界面科学
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胶体科学
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2022
·
IF 9.221
Ruping Deng,Yuquan Zhang,Xianyou Wang,Xi Xie,Yuan Song,Jing Bu,Changjun Min,Xiaocong Yuan
Label-free Raman spectroscopic detection of cellular elements is an important technique for biological science applications; however, the implementation of proactive intracellular detection remains a challenge. In this work, we demonstrate a graphene-based thermoelectric optical tweezers system for in situ intracellular Raman spectral detection on-a-chip applications. Because of the excellent photothermal conversion effect of the graphene substrate, a potent thermoelectric effect is generated to not only strengthen the trap for biological cells, but also accelerate metallic nanoparticles to permeate into these cells for intracellular Raman enhancement. An in situ intracellular Raman spectrum is thus acquired that offers the opportunity to distinguish the intracellular elements. This work provides a promising approach for use in cytobiology research and is expected to enable exciting new applications in the detection of complex intracellular life processes.
研究领域:
生物科学
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纳米技术
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光学工程
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2022
·
IF 5.518
Shuai Liu,Yue Hu,Jing Xia,Ning Li,Haiming Fan,Ming Duan
Although extensive work has been reported that micelles can induce depletion attraction between two solid spheres or a sphere and a plate, the effect of different micelles on the depletion between two soft surfaces has been rarely reported. Optical tweezers were used to measure the forces between two oil-in-water emulsions in solutions of sodium dodecylbenzenesulfonate (SDBS), cetyltrimethylammonium bromide (CTAB), and octylphenol polyoxyethylene ether with ten oxyethylene glycol ether (OP-10) at varying concentrations. When the concentration of surfactant below their critical micelle concentration (cmc), force profiles between two emulsion droplets were purely repulsive. As the concentration of SDBS or CTAB above its cmc, the attraction between like-charged O/W emulsion droplets was dominant. The coalescence of the like-charged O/W emulsion droplets is observed. For nonionic surfactants OP-10, even if the cmc had been reached, the attractive force between O/W emulsion droplets couldn’t be measured. Results shows that attractive forces between two like-charged emulsion droplets of several microns in solution can also be induced by ionic micelles and the depletion was enhanced by counterion osmotic pressure . Our work suggests that the effect of micelle-induced depletion on the force between two solid surfaces can be used to predict forces between several micrometers of emulsion droplets.
研究领域:
化学
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材料科学
·
界面科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Water Process Engineering
·
2023
·
IF 7
Qiang Liang,Xiujun Wang,Xiaoyue Zhang,Bo Jing,Ming Duan,Shenwen Fang
The branched amphiphilic copolymer of N-(3-dimethylaminopropyl) methacrylamide and polyether macromonomer (DA) can gather a large number of oil droplets and bubbles together to form oil aerated flocs, and cooperate with air-flotation cyclone separation device to achieve efficient oil-water separation. In this paper, the effects of DA and linear cationic flocculant polymethylacryloxyethyl trimethylammonium chloride (PDMC) on interaction between dispersed phases in produced water were studied from the microscopic point of view, and the reason why oil aerated flocs can be formed under the action of DA was analyzed. Firstly, the aggregation behaviors of the dispersed phases (including oil droplets and bubbles) in water were studied intuitively by microfluidic experiment. Then, the interaction between oil droplets and the interaction between oil droplet and bubble were studied by optical tweezers and oil-coated bubbles experiments, respectively. The experimental results showed that both the efficiencies of oil droplets coalescence and oil droplet-bubble adhesion of DA were 5 times higher than that of PDMC at concentration of 500 mg/L. DA can enhance the attraction force between oil droplets while PDMC cannot. The film drainage time of oil droplet-bubble adhesion of DA was 3 times shorter than that of PDMC. The increasing temperature and salinity had the negative effect on the film drainage oil droplet-bubble adhesion of DA. In addition, the type of attraction force between oil droplets under action of DA still needs analysis and the generation reason needs molecular dynamics simulation study. The research results of this paper can give a guide to the development of DA type flocculants.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
LANGMUIR
·
2020
·
IF 3.557
An Chen,Fajun Wang,Yiwei Zhou,Jian-hong Xu
Switchable surface-active colloid particles are critical to the preparation of switchable Pickering emulsions, which are widely involved in multitudinous fundamental and practical fields, such as biomedical, food products, and spinning cosmetics. The stability of switchable surface-active particles relies on the full understanding of interaction forces between individual colloid particles quantitatively. In this work, a dual-laser optical tweezers instrument was applied to measure the interaction forces between silica particles coated with a common cationic surfactant (cetyltrimethylammonium bromide, CTAB) in water, and all of the measured forces can be well fitted with the theoretical model derived from the Derjaguin–Landau–Verwey–Overbeek (DLVO) theory. It was revealed that the minimum surface distance to engender the interaction forces between silica particles was closer progressively with the increase of CTAB concentrations, suggesting that the introduction of CTAB molecules in the solution thinned the electric double layer. In addition, the minimum surface distance between surface-inactive silica particles further decreased compared to surface-active states, although the ζ-potential has returned to the initial value of bare silica in pure water when the molecular ratio of 1:1 anionic surfactant (sodium dodecyl sulfate, SDS) was added into the solution to switch the surface-active silica particles to surface-inactive states. Our results provide a considerate methodology for quantifying the interaction forces and investigating the switchable behaviors of CTAB molecules from the adsorption to desorption at the particle–water interfaces, which provide vital foresights into the stabilization mechanism of switchable surface-active colloid particles and the further development of switchable Pickering emulsions.
研究领域:
胶体科学
·
界面化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2021
·
IF 6.986
Wen-Kai Fang,Liu Liu,Li-ling Zhang,Da Liu,Yang Liu,Hong-Wu Tang
Alzheimer’s disease (AD), known as a progressive neurodegenerative disorder, has had a terrible impact on the health of aged people. Due to its severity, early diagnosis of AD is significant to retard the progress and provide timely treatment. Here, we report a fluorescence ratio detection of AD biomarker amyloid β oligomers (AβOs) by combining highly doped upconversion nanoparticles-SiO2@metal–organic framework/black hole quencher (H-USM/BHQ-1) microspheres with optical tweezer (OT) microscopic imaging. Optical trapping a single microsphere not only avoids the interference of fluid viscosity but also provides a high power density laser source to efficiently stimulate upconversion luminescence (UCL) of highly doped upconversion nanoparticles (H-UCNPs). Under this condition, H-UCNPs show stronger UCL and greater power-dependent properties compared to low-doped ones. Moreover, the closely packed quenching molecules BHQ-1 on a metal–organic framework (ZIF-8) exhibit excellent quenching efficiency for upconversion 525 and 540 nm emission. Also, the luminescent resonance energy transfer efficiency reaches 89.58%. When different concentrations of AβOs are present, the UCL540 recovers due to the decomposition of ZIF-8 and the release of BHQ-1. Using 540 and 654 nm emission ratio of highly doped UCNPs as reporters, the limit of detection reaches 28.4 pM for the quantitative determination of AβOs. Besides, this strategy is able to selectively quantify the AβO concentration. Therefore, we demonstrated the combination of optical trapping and highly doped UCNPs which is applied for the detection of AβOs with high sensitivity and specificity.
研究领域:
生物医学
·
神经科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LANGMUIR
·
2020
·
IF 3.557
An Chen,Xueyan Liu,Yuxin Wu,Guangsheng Luo,Jian-hong Xu
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.
研究领域:
化学工程
·
界面科学
·
胶体与表面化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）