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Mita M, Matsushima H, Ueda M, Ito H. In-situ high-speed atomic force microscopy observation of dynamic nanobubbles during water electrolysis. J Colloid Interface Sci 2022; 614:389-395. [DOI: 10.1016/j.jcis.2022.01.089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 01/10/2022] [Accepted: 01/13/2022] [Indexed: 10/19/2022]
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2
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Babu KS, Amamcharla JK. Generation methods, stability, detection techniques, and applications of bulk nanobubbles in agro-food industries: a review and future perspective. Crit Rev Food Sci Nutr 2022; 63:9262-9281. [PMID: 35467989 DOI: 10.1080/10408398.2022.2067119] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Nanobubble (NB) technologies have received considerable attention for various applications due to their low cost, eco-friendliness, scale-up potential, process control, and unique physical characteristics. NB stands for nanoscopic gaseous cavities, typically <1 μm in diameter. NBs can exist on surfaces (surface or interfacial NBs) and be dispersed in a bulk liquid phase (bulk NBs). Compared to the microbubbles, NBs exhibit high specific surface area, negative surface charge, and better adsorption. Bulk NBs can be generated by hydrodynamic/acoustic cavitation, electrolysis, water-solvent mixing, nano-membrane filtration, and so on. NBs exhibit extraordinary longevity compared to microbubbles, prompting the interest of the scientific community aiming for potential applications including medicine, agriculture, food, wastewater treatment, surface cleaning, and so on. Based on the limited amount of research work available regarding the influence of NBs on food matrices, further research, however, needs to be done to provide more insights into its applications in food industries. This review provides an overview of the generation methods for NBs, techniques to evaluate them, and a discussion of their stability and several applications in various fields of science were discussed. However, recent studies have revealed that, despite the many benefits of NB technologies, several NB generating approaches are still limited in their application in specific agro-food industries. Further study should focus on process optimization, integrating various NB generation techniques/combining with other emerging technologies in order to achieve rapid technical progress and industrialization of NB-based technologies.HighlightsNanobubbles (NBs) are stable spherical entities of gas within liquid and are operationally defined as having diameters less than 1 µm.Currently, various reported theories still lack the ability to explain the evidence and stability of NBs in water, numerous NB applications have emerged due to the unique properties of NBs.NB technologies can be applied to various food and dairy products (e.g. yogurt and ice cream) and other potential applications, including agriculture (e.g. seed germination and plant growth), wastewater treatment, surface cleaning, and so on.
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Affiliation(s)
- Karthik S Babu
- Department of Animal Sciences and Industry/Food Science Institute, Kansas State University, Manhattan, Kansas, USA
| | - Jayendra K Amamcharla
- Department of Animal Sciences and Industry/Food Science Institute, Kansas State University, Manhattan, Kansas, USA
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Olubowale O, Biswas S, Azom G, Prather BL, Owoso SD, Rinee KC, Marroquin K, Gates KA, Chambers MB, Xu A, Garno JC. "May the Force Be with You!" Force-Volume Mapping with Atomic Force Microscopy. ACS OMEGA 2021; 6:25860-25875. [PMID: 34660949 PMCID: PMC8515370 DOI: 10.1021/acsomega.1c03829] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 08/30/2021] [Indexed: 06/02/2023]
Abstract
Information of the chemical, mechanical, and electrical properties of materials can be obtained using force volume mapping (FVM), a measurement mode of scanning probe microscopy (SPM). Protocols have been developed with FVM for a broad range of materials, including polymers, organic films, inorganic materials, and biological samples. Multiple force measurements are acquired with the FVM mode within a defined 3D volume of the sample to map interactions (i.e., chemical, electrical, or physical) between the probe and the sample. Forces of adhesion, elasticity, stiffness, deformation, chemical binding interactions, viscoelasticity, and electrical properties have all been mapped at the nanoscale with FVM. Subsequently, force maps can be correlated with features of topographic images for identifying certain chemical groups presented at a sample interface. The SPM tip can be coated to investigate-specific reactions; for example, biological interactions can be probed when the tip is coated with biomolecules such as for recognition of ligand-receptor pairs or antigen-antibody interactions. This review highlights the versatility and diverse measurement protocols that have emerged for studies applying FVM for the analysis of material properties at the nanoscale.
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Xiong R, Xu RX, Huang C, De Smedt S, Braeckmans K. Stimuli-responsive nanobubbles for biomedical applications. Chem Soc Rev 2021; 50:5746-5776. [PMID: 33972972 DOI: 10.1039/c9cs00839j] [Citation(s) in RCA: 80] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Stimuli-responsive nanobubbles have received increased attention for their application in spatial and temporal resolution of diagnostic techniques and therapies, particularly in multiple imaging methods, and they thus have significant potential for applications in the field of biomedicine. This review presents an overview of the recent advances in the development of stimuli-responsive nanobubbles and their novel applications. Properties of both internal- and external-stimuli responsive nanobubbles are highlighted and discussed considering the potential features required for biomedical applications. Furthermore, the methods used for synthesis and characterization of nanobubbles are outlined. Finally, novel biomedical applications are proposed alongside the advantages and shortcomings inherent to stimuli-responsive nanobubbles.
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Affiliation(s)
- Ranhua Xiong
- Joint Laboratory of Advanced Biomedical Materials (NFU-UGent), College of Chemical Engineering, Nanjing Forestry University (NFU), Nanjing 210037, P. R. China. and Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, 9000 Ghent, Belgium.
| | - Ronald X Xu
- Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei 230022, P. R. China and Department of Biomedical Engineering, The Ohio State University, Columbus, OH 43210, USA
| | - Chaobo Huang
- Joint Laboratory of Advanced Biomedical Materials (NFU-UGent), College of Chemical Engineering, Nanjing Forestry University (NFU), Nanjing 210037, P. R. China.
| | - Stefaan De Smedt
- Joint Laboratory of Advanced Biomedical Materials (NFU-UGent), College of Chemical Engineering, Nanjing Forestry University (NFU), Nanjing 210037, P. R. China. and Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, 9000 Ghent, Belgium. and Centre for Advanced Light Microscopy, Ghent University, 9000, Ghent, Belgium.
| | - Kevin Braeckmans
- Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmaceutical Sciences, Ghent University, 9000 Ghent, Belgium. and Centre for Advanced Light Microscopy, Ghent University, 9000, Ghent, Belgium.
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Zhang F, Sun L, Yang H, Gui X, Schönherr H, Kappl M, Cao Y, Xing Y. Recent advances for understanding the role of nanobubbles in particles flotation. Adv Colloid Interface Sci 2021; 291:102403. [PMID: 33780858 DOI: 10.1016/j.cis.2021.102403] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 03/15/2021] [Accepted: 03/16/2021] [Indexed: 12/01/2022]
Abstract
Traditional froth flotation is the primary method for the separation and upgrading of fine mineral particles. However, it is still difficult for micro-fine and low-quality minerals to effectively separate. It is generally believed that bubble miniaturization is of great significance to improve flotation efficiency. Due to their unique physical and chemical properties, the application of nanobubbles (NBs) in ore flotation and other fields has been widely investigated as an important means to solve the problems of fine particle separation. Therefore, a fundamental understanding of the effect of NBs on flotation is a prerequisite to adapt it for the treatment of fine and low-quality minerals for separation. In this paper, recent advances in the field of nanobubble (NB) formation, preparation and stability are reviewed. In particular, we highlight the latest progress in the role of NBs on particles flotation and focus in particular on the particle-particle and particle-bubble interaction. A discussion of the current knowledge gap and future directions is provided.
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Affiliation(s)
- Fanfan Zhang
- School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China
| | - Lijuan Sun
- School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China
| | - Haichang Yang
- School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China
| | - Xiahui Gui
- National Engineering Research Center of Coal Preparation and Purification, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China
| | - Holger Schönherr
- Physical Chemistry I & Research Center of Micro and Nanochemistry and Engineering (Cμ), Department of Chemistry and Biology, University of Siegen, Adolf-Reichwein-Straße 2, Siegen 57076, Germany
| | - Michael Kappl
- Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz 55128, Germany
| | - Yijun Cao
- National Engineering Research Center of Coal Preparation and Purification, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China; School of Chemical Engineering and Technology, Zhengzhou University, Zhengzhou 450066, Henan, China).
| | - Yaowen Xing
- National Engineering Research Center of Coal Preparation and Purification, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China.
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Zhang F, Gui X, Xing Y, Cao Y, Che T. Study of Interactions between Interfacial Nanobubbles and Probes of Different Hydrophobicities. ACS OMEGA 2020; 5:20363-20372. [PMID: 32832789 PMCID: PMC7439380 DOI: 10.1021/acsomega.0c02327] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 07/23/2020] [Indexed: 05/17/2023]
Abstract
In this study, hydrophilic, medium hydrophobic, and strong hydrophobic probes are obtained via treatment with plasma and octadecyl trichlorosilane. The interaction between the probes and interfacial nanobubbles (INBs) is examined using atomic force microscopy. The results show that a hydrophilic probe can scan the true shape of the INBs, and the distance between the first inflection point and the zero point of the approach force curve is equal to the vertical height of the nanobubble. The medium hydrophobic probe caused severe deformation of INB morphologies in the horizontal direction during scanning; nevertheless, the complete shape of the INB is obtained using this probe by lowering the scanning parameters. However, the characteristic of the approach force curve proves that the size of the nanobubbles is underestimated. The strong hydrophobic probe deforms INB morphologies severely, whose size cannot be obtained. The maximum attractive force in the approach force curve and the adhesive force in the retract force curve obtained using the strong hydrophobic probe are approximately 6 and 12 nN, respectively, which are both higher than those of the hydrophilic and medium hydrophobic probes. It is reasoned that the liquid film is maintained between the hydrophilic probe and the INBs, the medium hydrophobic probe pierces the INBs slightly, while the strong hydrophobic probe punctures the liquid film and demonstrates a pinning effect.
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Affiliation(s)
- Fanfan Zhang
- School of Chemical
Engineering and Technology, China University
of Mining and Technology, No. 1 Daxue Road, Tongshan District, Xuzhou, Jiangsu 221116, China
| | - Xiahui Gui
- Chinese National Engineering Research Center
of Coal Preparation and Purification, China
University of Mining and Technology, No. 1 Daxue Road, Tongshan District, Xuzhou, Jiangsu 221116, China
| | - Yaowen Xing
- Chinese National Engineering Research Center
of Coal Preparation and Purification, China
University of Mining and Technology, No. 1 Daxue Road, Tongshan District, Xuzhou, Jiangsu 221116, China
| | - Yijun Cao
- Chinese National Engineering Research Center
of Coal Preparation and Purification, China
University of Mining and Technology, No. 1 Daxue Road, Tongshan District, Xuzhou, Jiangsu 221116, China
| | - Tao Che
- Yanzhou Coal Mining Company Limited, 98 Fushan South Road, Zoucheng, Shandong 273500, China
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Han B, Chang J, Song W, Sun Z, Yin C, Lv P, Wang X. Study on Micro Interfacial Charge Motion of Polyethylene Nanocomposite Based on Electrostatic Force Microscope. Polymers (Basel) 2019; 11:polym11122035. [PMID: 31818008 PMCID: PMC6960587 DOI: 10.3390/polym11122035] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 12/02/2019] [Accepted: 12/05/2019] [Indexed: 11/24/2022] Open
Abstract
The interface area of nano-dielectric is generally considered to play an important role in improving dielectric properties, especially in suppressing space charge. In order to study the role of interface area on a microscopic scale, the natural charge and injected charge movement and diffusion on the surface of pure LDPE and SiO2/LDPE nanocomposite were observed and studied by gradual discharge under electrostatic force microscope (EFM). It was detected that the charge in SiO2/LDPE nanocomposite moved towards the interface area and was captured, which indicates that the charge was trapped in the interface area and formed a barrier to the further injection of charge and improving the dielectric performance as a result. Moreover, pulsed electro-acoustic (PEA) short-circuited test after charge injection was carried out, and the change of total charge was calculated. The trend of charge decay in the EFM test is also generally consistent with that in PEA short-circuit test and can be used to verify one another. The results revealed the law of charge movement and verified the interface area can inhibit space charge injection in nano-dielectric at the microscale, which provides an experimental reference for relevant theoretical research.
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Affiliation(s)
- Bai Han
- Key Laboratory of Engineering Dielectrics and Its Application, Ministry of Education, Harbin University of Science and Technology, Harbin 150080, Heilongjiang, China; (W.S.); (Z.S.); (C.Y.); (P.L.); (X.W.)
- State Key Laboratory Breeding Base of Dielectrics Engineering, Harbin University of Science and Technology, Harbin 150080, Heilongjiang, China
- College of Electrical & Electronic Engineer, Harbin University of Science and Technology, Harbin 150080, Heilongjiang, China
- Correspondence: (B.H.); (J.C.); Tel.: +86-451-8639-1667 (B.H.); +86-188-4516-9304 (J.C.)
| | - Jiaxin Chang
- Key Laboratory of Engineering Dielectrics and Its Application, Ministry of Education, Harbin University of Science and Technology, Harbin 150080, Heilongjiang, China; (W.S.); (Z.S.); (C.Y.); (P.L.); (X.W.)
- State Key Laboratory Breeding Base of Dielectrics Engineering, Harbin University of Science and Technology, Harbin 150080, Heilongjiang, China
- College of Electrical & Electronic Engineer, Harbin University of Science and Technology, Harbin 150080, Heilongjiang, China
- Correspondence: (B.H.); (J.C.); Tel.: +86-451-8639-1667 (B.H.); +86-188-4516-9304 (J.C.)
| | - Wei Song
- Key Laboratory of Engineering Dielectrics and Its Application, Ministry of Education, Harbin University of Science and Technology, Harbin 150080, Heilongjiang, China; (W.S.); (Z.S.); (C.Y.); (P.L.); (X.W.)
- State Key Laboratory Breeding Base of Dielectrics Engineering, Harbin University of Science and Technology, Harbin 150080, Heilongjiang, China
- College of Electrical & Electronic Engineer, Harbin University of Science and Technology, Harbin 150080, Heilongjiang, China
| | - Zhi Sun
- Key Laboratory of Engineering Dielectrics and Its Application, Ministry of Education, Harbin University of Science and Technology, Harbin 150080, Heilongjiang, China; (W.S.); (Z.S.); (C.Y.); (P.L.); (X.W.)
- State Key Laboratory Breeding Base of Dielectrics Engineering, Harbin University of Science and Technology, Harbin 150080, Heilongjiang, China
- College of Electrical & Electronic Engineer, Harbin University of Science and Technology, Harbin 150080, Heilongjiang, China
| | - Chuqi Yin
- Key Laboratory of Engineering Dielectrics and Its Application, Ministry of Education, Harbin University of Science and Technology, Harbin 150080, Heilongjiang, China; (W.S.); (Z.S.); (C.Y.); (P.L.); (X.W.)
- State Key Laboratory Breeding Base of Dielectrics Engineering, Harbin University of Science and Technology, Harbin 150080, Heilongjiang, China
- College of Electrical & Electronic Engineer, Harbin University of Science and Technology, Harbin 150080, Heilongjiang, China
| | - Penghao Lv
- Key Laboratory of Engineering Dielectrics and Its Application, Ministry of Education, Harbin University of Science and Technology, Harbin 150080, Heilongjiang, China; (W.S.); (Z.S.); (C.Y.); (P.L.); (X.W.)
- State Key Laboratory Breeding Base of Dielectrics Engineering, Harbin University of Science and Technology, Harbin 150080, Heilongjiang, China
- College of Electrical & Electronic Engineer, Harbin University of Science and Technology, Harbin 150080, Heilongjiang, China
| | - Xuan Wang
- Key Laboratory of Engineering Dielectrics and Its Application, Ministry of Education, Harbin University of Science and Technology, Harbin 150080, Heilongjiang, China; (W.S.); (Z.S.); (C.Y.); (P.L.); (X.W.)
- State Key Laboratory Breeding Base of Dielectrics Engineering, Harbin University of Science and Technology, Harbin 150080, Heilongjiang, China
- College of Electrical & Electronic Engineer, Harbin University of Science and Technology, Harbin 150080, Heilongjiang, China
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Li D, Zeng B, Wang Y. Probing the "Gas Tunnel" between Neighboring Nanobubbles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:15029-15037. [PMID: 31702925 DOI: 10.1021/acs.langmuir.9b02682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Surface nanobubbles are the main gaseous domains forming at solid-liquid interfaces, and their abnormally long lifetime (stability) is still an open question. A hypothesis "gas tunnel" was presented in a recent simulation study [ACS Nano 2018, 12 (3), 2603-2609], which was thought to connect two neighboring nanobubbles and make the nanobubbles remain stable. Herein, we aim to experimentally investigate the existence of gas tunnel and its role in governing nanobubble dynamics. By using an atomic force microscope, mutual effects between different gaseous domains including nanobubbles, nanopancakes, and nanobubble-pancake composite on a PS substrate undergoing violent tip perturbation and their effects on the undisturbed neighbors were investigated. The pancake between two nanobubbles can behave as a visible gas tunnel under the tip-bubble interaction. Based on statistical analysis of volume change in the different gas domains, the concept of a generalized gas tunnel is presented and experimentally verified. Nanobubbles are surrounded by a water depletion layer which will act as a channel along solid/liquid surfaces for adjacent nanobubbles to communicate with each other. Moreover, the change in contact angle of nanobubbles with the concentration of local gas oversaturation was studied, and the equilibrium contact angle of nanobubbles is further verified experimentally.
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Affiliation(s)
- Dayong Li
- School of Mechanical Engineering , Heilongjiang University of Science and Technology , No. 2468 Puyuan Road, Songbei district , Harbin 150022 , P. R. China
- Robotics Institute, School of Mechanical Engineering and Automation , Beihang University , No. 37 Xueyuan Road, Haidian district , Beijing 100191 , P. R. China
| | - Binglin Zeng
- Robotics Institute, School of Mechanical Engineering and Automation , Beihang University , No. 37 Xueyuan Road, Haidian district , Beijing 100191 , P. R. China
| | - Yuliang Wang
- Robotics Institute, School of Mechanical Engineering and Automation , Beihang University , No. 37 Xueyuan Road, Haidian district , Beijing 100191 , P. R. China
- Beijing Advanced Innovation Center for Biomedical Engineering , Beihang University , No. 37 Xueyuan Road, Haidian district , Beijing 100083 , P. R. China
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9
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Theodorakis PE, Che Z. Surface nanobubbles: Theory, simulation, and experiment. A review. Adv Colloid Interface Sci 2019; 272:101995. [PMID: 31394435 DOI: 10.1016/j.cis.2019.101995] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 07/19/2019] [Accepted: 07/23/2019] [Indexed: 01/08/2023]
Abstract
Surface nanobubbles (NBs) are stable gaseous phases in liquids that form at the interface with solid substrates. They have been particularly intriguing for their high stability that contradicts theoretical expectations and their potential relevance for many technological applications. Here, we present the current state of the art in this research area by discussing and contrasting main results obtained from theory, simulation and experiment, and presenting their limitations. We also provide future perspectives anticipating that this review will stimulate further studies in the research area of surface NBs.
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Hain N, Handschuh-Wang S, Wesner D, Druzhinin SI, Schönherr H. Multimodal microscopy-based identification of surface nanobubbles. J Colloid Interface Sci 2019; 547:162-170. [PMID: 30952078 DOI: 10.1016/j.jcis.2019.03.084] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Revised: 03/24/2019] [Accepted: 03/25/2019] [Indexed: 10/27/2022]
Abstract
HYPOTHESIS Surface nanobubbles, which were controversially discussed in the literature, promise a number of outstanding applications, and their presence may hamper nanoscale processes at solid-aqueous interfaces. A most crucial and yet unsolved question is the rapid and conclusive identification of gas-filled (surface) nanobubbles. We hypothesize that surface nanobubbles and oil nanodroplets can be conclusively differentiated in co-localization experiments with atomic force microscopy (AFM) and time-resolved fluorescence microscopy by localizing tracer fluorophores and analyzing their fluorescence lifetimes. EXPERIMENTS Combined AFM and fluorescence lifetime imaging microscopy (FLIM) were conducted to localize the various interfaces labelled by the reporter dye rhodamine 6G (Rh6G). The dependence of the fluorescence lifetime of Rh6G on its local environment was determined for air/water, water/glass and polysiloxane/water interfaces under different conditions. FINDINGS In in situ co-localization experiments, surface nanobubbles labeled with Rh6G were probed by AFM with high spatial resolution and were differentiated from polysiloxane droplets as well as contamination originating from lubricant-coated syringe needles owing to the characteristic short fluorescence lifetime of Rh6G at the gas/water interface observed in FLIM. In particular, this approach lends itself to conclusively identify and rapidly differentiate these gas-filled entities from adsorbed contamination, such as siloxane-based oil nanodroplets.
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Affiliation(s)
- Nicole Hain
- Physical Chemistry I & Research Center of Micro and Nanochemistry and Engineering (Cμ), Department of Chemistry and Biology, School of Science and Technology, University of Siegen, Adolf-Reichwein-Str. 2, 57076 Siegen, Germany
| | - Stephan Handschuh-Wang
- Physical Chemistry I & Research Center of Micro and Nanochemistry and Engineering (Cμ), Department of Chemistry and Biology, School of Science and Technology, University of Siegen, Adolf-Reichwein-Str. 2, 57076 Siegen, Germany
| | - Daniel Wesner
- Physical Chemistry I & Research Center of Micro and Nanochemistry and Engineering (Cμ), Department of Chemistry and Biology, School of Science and Technology, University of Siegen, Adolf-Reichwein-Str. 2, 57076 Siegen, Germany
| | - Sergey I Druzhinin
- Physical Chemistry I & Research Center of Micro and Nanochemistry and Engineering (Cμ), Department of Chemistry and Biology, School of Science and Technology, University of Siegen, Adolf-Reichwein-Str. 2, 57076 Siegen, Germany
| | - Holger Schönherr
- Physical Chemistry I & Research Center of Micro and Nanochemistry and Engineering (Cμ), Department of Chemistry and Biology, School of Science and Technology, University of Siegen, Adolf-Reichwein-Str. 2, 57076 Siegen, Germany.
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Hu X, Nanney W, Umeda K, Ye T, Martini A. Combined Experimental and Simulation Study of Amplitude Modulation Atomic Force Microscopy Measurements of Self-Assembled Monolayers in Water. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:9627-9633. [PMID: 30060661 DOI: 10.1021/acs.langmuir.8b01609] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Atomic force microscopy (AFM) can be used to measure surface properties at the nanoscale. However, interpretation of measurements from amplitude modulation AFM (AM-AFM) in liquid is not straightforward due to the interactions between the AFM tip, the surface being imaged, and the water. In this work, amplitude-distance measurements and molecular dynamics simulations of AM-AFM were employed to study the effect of surface chemistry on the amplitude of tip oscillation in water. The sample surfaces consisted of self-assembled monolayers where the hydrophilicity or hydrophobicity was determined by the terminal group of the alkanethiols. Analysis showed that surface chemical composition influences the hydration structure near the interface which affects the forces experienced by the tip and in turn changes the amplitude profile. This observation could aid our understanding of AM-AFM measurements of interfacial phenomena on various surfaces in water.
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Affiliation(s)
- Xiaoli Hu
- Department of Mechanical Engineering , University of California-Merced , 5200 N. Lake Road , Merced , California 95343 , United States
| | - Warren Nanney
- Chemistry and Chemical Biology , University of California-Merced , 5200 N. Lake Road , Merced , California 95343 , United States
| | - Kenichi Umeda
- Department of Advanced Material Science , the University of Tokyo , 5-1-5, Kashiwanoha , Kashiwa , Chiba 277-8561 , Japan
| | - Tao Ye
- Chemistry and Chemical Biology , University of California-Merced , 5200 N. Lake Road , Merced , California 95343 , United States
| | - Ashlie Martini
- Department of Mechanical Engineering , University of California-Merced , 5200 N. Lake Road , Merced , California 95343 , United States
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12
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Shih HJ, Dai CL, Shih PJ. Tip Pressure on Semicircular Specimens in Tapping Mode Atomic Force Microscopy in Viscous Fluid Environments. SENSORS (BASEL, SWITZERLAND) 2017; 17:E2182. [PMID: 28937607 PMCID: PMC5676617 DOI: 10.3390/s17102182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 09/21/2017] [Accepted: 09/21/2017] [Indexed: 11/18/2022]
Abstract
Tapping mode (TM) atomic force microscopy (AFM) in a liquid environment is widely used to measure the contours of biological specimens. The TM triggers the AFM probe approximately at the resonant frequencies and controls the tip such that it periodically touches the specimen along the scanning path. The AFM probe and its tip produce a hydrodynamic pressure on the probe itself and press the specimen. The tip to specimen size ratio is known to affect the measurement accuracy of AFM, however, few studies have focused on the hydrodynamic pressure caused by the effects of specimen size. Such pressure affects the contour distortion of the biological specimen. In this study, a semi-analytical method is employed for a semicircular specimen to analyze the vorticity and pressure distributions for specimens of various sizes and at various tip locations. Changes in pressure distribution, fluid spin motion, and specimen deformation are identified as the tip approaches the specimen. The results indicate the following: the specimen surface experiences the highest pressure when the specimen diameter equals the tip width; the vorticity between tip and specimen is complex when the tip is close to the specimen center line; and the specimen inflates when the tip is aligned with the specimen center line.
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Affiliation(s)
- Hua-Ju Shih
- Institute of Applied Mechanics, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan.
| | - Ching-Liang Dai
- Department of Mechanical Engineering, National Chung Hsing University, No. 145, Xingda Rd. South Dist., Taichung 40227, Taiwan.
| | - Po-Jen Shih
- Department of Civil and Environmental Engineering, National University of Kaohsiung, No. 700, Kaohsiung University Rd., Nanzih District, Kaohsiung 81148, Taiwan.
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Teshima H, Nishiyama T, Takahashi K. Nanoscale pinning effect evaluated from deformed nanobubbles. J Chem Phys 2017; 146:014708. [PMID: 28063422 DOI: 10.1063/1.4973385] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Classical thermodynamics theory predicts that nanosized bubbles should disappear in a few hundred microseconds. The surprisingly long lifetime and stability of nanobubbles are therefore interesting research subjects. It has been proposed that the stability of nanobubbles arises through pinning of the three-phase contact line, which results from intrinsic nanoscale geometrical and chemical heterogeneities of the substrate. However, a definitive explanation of nanobubble stability is still lacking. In this work, we examined the stability mechanism by introducing a "pinning force." We investigated nanobubbles at a highly ordered pyrolytic graphite/pure water interface by peak force quantitative nano-mechanical mapping and estimated the pinning force and determined its maximum value. We then observed the shape of shrinking nanobubbles. Because the diameter of the shrinking nanobubbles was pinned, the height decreased and the contact angle increased. This phenomenon implies that the stability results from the pinning force, which flattens the bubble through the pinned three-phase contact line and prevents the Laplace pressure from increasing. The pinning force can also explain the metastability of coalesced nanobubbles, which have two semispherical parts that are joined to form a dumbbell-like shape. The pinning force of the semispherical parts was stronger than that of the joint region. This result demonstrates that the contact line of the semispherical parts is pinned strongly to keep the dumbbell-like shape. Furthermore, we proposed a nanobubble generation mechanism for the solvent-exchange method and explained why the pinning force of large nanobubbles was not initially at its maximum value, as it was for small nanobubbles.
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Affiliation(s)
- Hideaki Teshima
- Department of Aeronautics and Astronautics, Kyushu University, Nishi-Ku, Motooka 744, Fukuoka 819-0395, Japan
| | - Takashi Nishiyama
- Department of Aeronautics and Astronautics, Kyushu University, Nishi-Ku, Motooka 744, Fukuoka 819-0395, Japan
| | - Koji Takahashi
- Department of Aeronautics and Astronautics, Kyushu University, Nishi-Ku, Motooka 744, Fukuoka 819-0395, Japan
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14
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Guan D, Barraud C, Charlaix E, Tong P. Noncontact Viscoelastic Measurement of Polymer Thin Films in a Liquid Medium Using Long-Needle Atomic Force Microscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:1385-1390. [PMID: 28094528 DOI: 10.1021/acs.langmuir.6b04066] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We report the noncontact measurement of the viscoelastic property of polymer thin films in a liquid medium using frequency-modulation atomic force microscopy with a newly developed long-needle probe. The probe contains a long vertical glass fiber with one end adhered to a cantilever beam and the other end with a sharp tip placed near the liquid-film interface. The nanoscale flow generated by the resonant oscillation of the needle tip provides a precise hydrodynamic force acting on the soft surface of the thin film. By accurately measuring the mechanical response of the thin film, we obtain the elastic and loss moduli of the thin film using the linear response theory of elastohydrodynamics. The experiment verifies the theory and demonstrates its applications. The technique can be used to accurately measure the viscoelastic property of soft surfaces, such as those made of polymers, nanobubbles, live cells, and tissues.
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Affiliation(s)
- Dongshi Guan
- Department of Physics, Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong
| | - Chloé Barraud
- LIPHY, Université Grenoble Alpes , F-38000 Grenoble, France
| | | | - Penger Tong
- Department of Physics, Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong
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15
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Wang X, Zhao B, Hu J, Wang S, Tai R, Gao X, Zhang L. Interfacial gas nanobubbles or oil nanodroplets? Phys Chem Chem Phys 2017; 19:1108-1114. [DOI: 10.1039/c6cp05137e] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The force curves on nanobubbles and PDMS nanodroplets are quite different. The peculiar plateaus on nanobubbles can be used to distinguish these two easily confusing objects.
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Affiliation(s)
- Xingya Wang
- Shanghai Synchrotron Radiation Facility
- Chinese Academy of Sciences
- Shanghai 201204
- China
- Key Laboratory of Interfacial Physics and Technology
| | - Binyu Zhao
- State Key Laboratory of Traction Power
- School of Mechanics and Engineering
- Southwest Jiaotong University
- Chengdu 610031
- China
| | - Jun Hu
- Key Laboratory of Interfacial Physics and Technology
- Shanghai Institute of Applied Physics
- Chinese Academy of Sciences
- Shanghai 201800
- China
| | - Shuo Wang
- Key Laboratory of Interfacial Physics and Technology
- Shanghai Institute of Applied Physics
- Chinese Academy of Sciences
- Shanghai 201800
- China
| | - Renzhong Tai
- Shanghai Synchrotron Radiation Facility
- Chinese Academy of Sciences
- Shanghai 201204
- China
- Key Laboratory of Interfacial Physics and Technology
| | - Xingyu Gao
- Shanghai Synchrotron Radiation Facility
- Chinese Academy of Sciences
- Shanghai 201204
- China
| | - Lijuan Zhang
- Shanghai Synchrotron Radiation Facility
- Chinese Academy of Sciences
- Shanghai 201204
- China
- Key Laboratory of Interfacial Physics and Technology
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16
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Attard P. Pinning Down the Reasons for the Size, Shape, and Stability of Nanobubbles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:11138-11146. [PMID: 27391651 DOI: 10.1021/acs.langmuir.6b01563] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
A thermodynamic analysis of the size, shape, and stability of nanobubbles is carried out by modifying classical nucleation theory to include the supersaturation dependence of the surface tension. It is shown that the free energy of a nanobubble is a minimum at the critical radius when the contact line is pinned, that the size of the nanobubble is determined by the decrease in the surface tension caused by the degree of supersaturation, and that together these explain the increased exterior contact angle of a nanobubble compared with the corresponding angle of a macroscopic bubble or droplet on the same surface.
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17
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Alheshibri M, Qian J, Jehannin M, Craig VSJ. A History of Nanobubbles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:11086-11100. [PMID: 27594543 DOI: 10.1021/acs.langmuir.6b02489] [Citation(s) in RCA: 239] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We follow the history of nanobubbles from the earliest experiments pointing to their existence to recent years. We cover the effect of Laplace pressure on the thermodynamic stability of nanobubbles and why this implies that nanobubbles are thermodynamically never stable. Therefore, understanding bubble stability becomes a consideration of the rate of bubble dissolution, so the dominant approach to understanding this is discussed. Bulk nanobubbles (or fine bubbles) are treated separately from surface nanobubbles as this reflects their separate histories. For each class of nanobubbles, we look at the early evidence for their existence, methods for the production and characterization of nanobubbles, evidence that they are indeed gaseous, or otherwise, and theories for their stability. We also look at applications of both surface and bulk nanobubbles.
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Affiliation(s)
- Muidh Alheshibri
- Department of Applied Mathematics, Research School of Physics and Engineering, Australian National University , Canberra, ACT 2600, Australia
| | - Jing Qian
- Department of Applied Mathematics, Research School of Physics and Engineering, Australian National University , Canberra, ACT 2600, Australia
| | - Marie Jehannin
- Department of Applied Mathematics, Research School of Physics and Engineering, Australian National University , Canberra, ACT 2600, Australia
| | - Vincent S J Craig
- Department of Applied Mathematics, Research School of Physics and Engineering, Australian National University , Canberra, ACT 2600, Australia
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18
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Guo Z, Liu Y, Xiao Q, Zhang X. Hidden Nanobubbles in Undersaturated Liquids. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:11328-11334. [PMID: 27252114 DOI: 10.1021/acs.langmuir.6b01766] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Here, we propose theoretically the existence of a new type of nanobubble in undersaturated liquids. These nanobubbles have a concave vapor-liquid interface featured with a negative curvature rather than a positive curvature for nanobubbles in supersaturated liquids, so that they often hide inside of the substrate textures and it might not be easy to characterize them through atomic force microscopy (AFM) measurements. However, these hidden nanobubbles are still stabilized by the contact line pinning effect and stay at the thermodynamically metastable state. We further demonstrate that similar to the nanobubbles in supersaturated liquids the contact angle of the hidden nanobubbles is more sensitive to the nanobubble size rather than the substrate chemistry, and their curvature radius is dependent on the chemical potential but independent of the base radius. Finally, we show several potential situations for the appearance of the hidden nanobubbles.
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Affiliation(s)
- Zhenjiang Guo
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology , Beijing 100029, China
| | - Yawei Liu
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology , Beijing 100029, China
| | - Qianxiang Xiao
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology , Beijing 100029, China
| | - Xianren Zhang
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology , Beijing 100029, China
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19
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Hain N, Wesner D, Druzhinin SI, Schönherr H. Surface Nanobubbles Studied by Time-Resolved Fluorescence Microscopy Methods Combined with AFM: The Impact of Surface Treatment on Nanobubble Nucleation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:11155-11163. [PMID: 27268423 DOI: 10.1021/acs.langmuir.6b01662] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The impact of surface treatment and modification on surface nanobubble nucleation in water has been addressed by a new combination of fluorescence lifetime imaging microscopy (FLIM) and atomic force microscopy (AFM). In this study, rhodamine 6G (Rh6G)-labeled surface nanobubbles nucleated by the ethanol-water exchange were studied on differently cleaned borosilicate glass, silanized glass as well as self-assembled monolayers on transparent gold by combined AFM-FLIM. While the AFM data confirmed earlier reports on surface nanobubble nucleation, size, and apparent contact angles in dependence of the underlying substrate, the colocalization of these elevated features with highly fluorescent features observed in confocal intensity images added new information. By analyzing the characteristic contributions to the excited state lifetime of Rh6G in decay curves obtained from time-correlated single photon counting (TCSPC) experiments, the characteristic short-lived (<600 ps) component of could be associated with an emission at the gas-water interface. Its colocalization with nanobubble-like features in the AFM height images provides evidence for the observation of gas-filled surface nanobubbles. While piranha-cleaned glass supported nanobubbles, milder UV-ozone or oxygen plasma treatment afforded glass-water interfaces, where no nanobubbles were observed by combined AFM-FLIM. Finally, the number density of nanobubbles scaled inversely with increasing surface hydrophobicity.
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Affiliation(s)
- Nicole Hain
- Physical Chemistry I, Department of Chemistry and Biology & Research Center of Micro and Nanochemistry and Engineering (Cμ), University of Siegen , Adolf-Reichwein-Strasse 2, 57076 Siegen, Germany
| | - Daniel Wesner
- Physical Chemistry I, Department of Chemistry and Biology & Research Center of Micro and Nanochemistry and Engineering (Cμ), University of Siegen , Adolf-Reichwein-Strasse 2, 57076 Siegen, Germany
| | - Sergey I Druzhinin
- Physical Chemistry I, Department of Chemistry and Biology & Research Center of Micro and Nanochemistry and Engineering (Cμ), University of Siegen , Adolf-Reichwein-Strasse 2, 57076 Siegen, Germany
| | - Holger Schönherr
- Physical Chemistry I, Department of Chemistry and Biology & Research Center of Micro and Nanochemistry and Engineering (Cμ), University of Siegen , Adolf-Reichwein-Strasse 2, 57076 Siegen, Germany
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20
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Song B, Chen K, Schmittel M, Schönherr H. AFM Study of Surface Nanobubbles on Binary Self-Assembled Monolayers on Ultraflat Gold with Identical Macroscopic Static Water Contact Angles and Different Terminal Functional Groups. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:11172-11178. [PMID: 27297876 DOI: 10.1021/acs.langmuir.6b01775] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
All experimental findings related to surface nanobubbles, such as their pronounced stability and the striking differences of macroscopic and apparent nanoscopic contact angles, need to be addressed in any theory or model of surface nanobubbles. In this work we critically test a recent explanation of surface nanobubble stability and their consequences and contrast this with previously proposed models. In particular, we elucidated the effect of surface chemical composition of well-controlled solid-aqueous interfaces of identical roughness and defect density on the apparent nanoscopic contact angles. Expanding on a previous atomic force microscopy (AFM) study on the systematic variation of the macroscopic wettability using binary self-assembled monolayers (SAMs) on ultraflat template stripped gold (TSG), we assessed here the effect of different surface chemical composition for macroscopically identical static water contact angles. SAMs on TSG with a constant macroscopic water contact angle of 81 ± 2° were obtained by coadsorption of a methyl-terminated thiol and a second thiol with different terminal functional groups, including hydroxy, amino, and carboxylic acid groups. In addition, surface nanobubbles formed by entrainment of air on SAMs of a bromoisobutyrate-terminated thiol were analyzed by AFM. Despite the widely differing surface potentials and different functionality, such as hydrogen bond acceptor or donor, and different dipole moments and polarizability, the nanoscopic contact angles (measured through the condensed phase and corrected for AFM tip broadening effects) were found to be 145 ± 10° for all surfaces. Hence, different chemical functionalities at identical macroscopic static water contact angle do not noticeably influence the apparent nanoscopic contact angle of surface nanobubbles. This universal contact angle is in agreement with recent models that rely on contact line pinning and the equilibrium of gas outflux due to the Laplace pressure and gas influx due to gas oversaturation in the aqueous medium.
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Affiliation(s)
- Bo Song
- Physical Chemistry I, Department of Chemistry and Biology, University of Siegen , Adolf-Reichwein-Straße 2, 57076 Siegen, Germany
- Research Center of Micro and Nanochemistry and Engineering (Cμ), University of Siegen , Adolf-Reichwein-Straße 2, 57076 Siegen, Germany
- Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis, Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, College of Chemistry, Chemical Engineering and Materials Science, Soochow University , Suzhou 215123, China
| | - Kun Chen
- Research Center of Micro and Nanochemistry and Engineering (Cμ), University of Siegen , Adolf-Reichwein-Straße 2, 57076 Siegen, Germany
- Organic Chemistry I, Department of Chemistry and Biology, University of Siegen , Adolf-Reichwein-Straße 2, 57076 Siegen, Germany
| | - Michael Schmittel
- Research Center of Micro and Nanochemistry and Engineering (Cμ), University of Siegen , Adolf-Reichwein-Straße 2, 57076 Siegen, Germany
- Organic Chemistry I, Department of Chemistry and Biology, University of Siegen , Adolf-Reichwein-Straße 2, 57076 Siegen, Germany
| | - Holger Schönherr
- Physical Chemistry I, Department of Chemistry and Biology, University of Siegen , Adolf-Reichwein-Straße 2, 57076 Siegen, Germany
- Research Center of Micro and Nanochemistry and Engineering (Cμ), University of Siegen , Adolf-Reichwein-Straße 2, 57076 Siegen, Germany
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21
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Zhao B, Wang X, Wang S, Tai R, Zhang L, Hu J. In situ measurement of contact angles and surface tensions of interfacial nanobubbles in ethanol aqueous solutions. SOFT MATTER 2016; 12:3303-3309. [PMID: 26954468 DOI: 10.1039/c5sm02871j] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The astonishing long lifetime and large contact angles of interfacial nanobubbles are still in hot debate despite numerous experimental and theoretical studies. One hypothesis to reconcile the two abnormalities of interfacial nanobubbles is that they have low surface tensions. However, few studies have been reported to measure the surface tensions of nanobubbles due to the lack of effective measurements. Herein, we investigate the in situ contact angles and surface tensions of individual interfacial nanobubbles immersed in different ethanol aqueous solutions using quantitative nanomechanical atomic force microscopy (AFM). The results showed that the contact angles of nanobubbles in the studied ethanol solutions were also much larger than the corresponding macroscopic counterparts on the same substrate, and they decreased with increasing ethanol concentrations. More significantly, the surface tensions calculated were much lower than those of the gas-liquid interfaces of the solutions at the macroscopic scale but have similar tendencies with increasing ethanol concentrations. Those results are expected to be helpful in further understanding the stability of interfacial nanobubbles in complex solutions.
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Affiliation(s)
- Binyu Zhao
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China.
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22
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Guo Z, Liu Y, Xiao Q, Schönherr H, Zhang X. Modeling the Interaction between AFM Tips and Pinned Surface Nanobubbles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:751-8. [PMID: 26751634 DOI: 10.1021/acs.langmuir.5b04162] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Although the morphology of surface nanobubbles has been studied widely with different AFM modes, AFM images may not reflect the real shapes of the nanobubbles due to AFM tip-nanobubble interactions. In addition, the interplay between surface nanobubble deformation and induced capillary force has not been well understood in this context. In our work we used constraint lattice density functional theory to investigate the interaction between AFM tips and pinned surface nanobubbles systematically, especially concentrating on the effects of tip hydrophilicity and shape. For a hydrophilic tip contacting a nanobubble, its hydrophilic nature facilitates its departure from the bubble surface, displaying a weak and intermediate-range attraction. However, when the tip squeezes the nanobubble during the approach process, the nanobubble shows an elastic effect that prevents the tip from penetrating the bubble, leading to a strong nanobubble deformation and repulsive interactions. On the contrary, a hydrophobic tip can easily pierce the vapor-liquid interface of the nanobubble during the approach process, leading to the disappearance of the repulsive force. In the retraction process, however, the adhesion between the tip and the nanobubble leads to a much stronger lengthening effect on nanobubble deformation and a strong long-range attractive force. The trends of force evolution from our simulations agree qualitatively well with recent experimental AFM observations. This favorable agreement demonstrates that our model catches the main intergradient of tip-nanobubble interactions for pinned surface nanobubbles and may therefore provide important insight into how to design minimally invasive AFM experiments.
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Affiliation(s)
- Zhenjiang Guo
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology , Beijing 100029, China
| | - Yawei Liu
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology , Beijing 100029, China
| | - Qianxiang Xiao
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology , Beijing 100029, China
| | - Holger Schönherr
- Physical Chemistry I, Department of Chemistry and Biology & Research Center of Micro and Nanochemistry and Engineering (Cμ), University of Siegen , Adolf-Reichwein-Str. 2, 57076 Siegen, Germany
| | - Xianren Zhang
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology , Beijing 100029, China
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23
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Zhang X, Wang J, Bao L, Dietrich E, van der Veen RCA, Peng S, Friend J, Zandvliet HJW, Yeo L, Lohse D. Mixed mode of dissolving immersed nanodroplets at a solid-water interface. SOFT MATTER 2015; 11:1889-1900. [PMID: 25605229 DOI: 10.1039/c4sm02397h] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The dissolution dynamics of microscopic oil droplets (less than 1 μm in height, i.e. nanodroplets) on a hydrophobilized silicon surface in water was experimentally studied. The lateral diameter was monitored using confocal microscopy, whereas the contact angle was measured by (disruptive) droplet polymerisation of the droplet. In general, we observed the droplets to dissolve in a mixed mode, i.e., neither in the constant contact angle mode nor in the constant contact radius mode. This means that both the lateral diameter and the contact angle of the nanodroplets decrease during the dissolution process. On average, the dissolution rate is faster for droplets with larger initial size. Droplets with the same initial size can, however, possess different dissolution rates. We ascribe the non-universal dissolution rates to chemical and geometric surface heterogeneities (that lead to contact line pinning) and cooperative effects from the mass exchange among neighbouring droplets.
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Affiliation(s)
- Xuehua Zhang
- School of Civil, Environmental and Chemical Engineering, RMIT University, Melbourne, VIC 3001, Australia.
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24
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Shi C, Cui X, Xie L, Liu Q, Chan DYC, Israelachvili JN, Zeng H. Measuring forces and spatiotemporal evolution of thin water films between an air bubble and solid surfaces of different hydrophobicity. ACS NANO 2015; 9:95-104. [PMID: 25514470 DOI: 10.1021/nn506601j] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A combination of atomic force microscopy (AFM) and reflection interference contrast microscopy (RICM) was used to measure simultaneously the interaction force and the spatiotemporal evolution of the thin water film between a bubble in water and mica surfaces with varying degrees of hydrophobicity. Stable films, supported by the repulsive van der Waals-Casimir-Lifshitz force were always observed between air bubble and hydrophilic mica surfaces (water contact angle, θ(w) < 5°) whereas bubble attachment occurred on hydrophobized mica surfaces. A theoretical model, based on the Reynolds lubrication theory and the augmented Young-Laplace equation including the effects of disjoining pressure, provided excellent agreement with experiment results, indicating the essential physics involved in the interaction between air bubble and solid surfaces can be elucidated. A hydrophobic interaction free energy per unit area of the form: WH(h) = -γ(1 - cos θ(w))exp(-h/D(H)) can be used to quantify the attraction between bubble and hydrophobized solid substrate at separation, h, with γ being the surface tension of water. For surfaces with water contact angle in the range 45° < θ(w) < 90°, the decay length DH varied between 0.8 and 1.0 nm. This study quantified the hydrophobic interaction in asymmetric system between air bubble and hydrophobic surfaces, and provided a feasible method for synchronous measurements of the interaction forces with sub-nN resolution and the drainage dynamics of thin films down to nm thickness.
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Affiliation(s)
- Chen Shi
- Department of Chemical and Materials Engineering, University of Alberta , Edmonton, Alberta T6G 2 V4, Canada
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Walczyk W, Schönherr H. Dimensions and the profile of surface nanobubbles: tip-nanobubble interactions and nanobubble deformation in atomic force microscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:11955-11965. [PMID: 25222759 DOI: 10.1021/la502918u] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The interactions between argon surface nanobubbles and AFM tips on HOPG (highly oriented pyrolitic graphite) in water and the concomitant nanobubble deformation were analyzed as a function of position on the nanobubbles in a combined tapping mode and force-volume mode AFM study with hydrophilic and hydrophobic AFM tips. On the basis of the detailed analysis of force-distance curves acquired on the bubbles, we found that for hydrophobic tips the bubble interface may jump toward the tip and that the tip-bubble interaction strength and the magnitude of the bubble deformation were functions of vertical and horizontal position of the tip on the bubble and depended on the bubble size and tip size and functionality. The spatial variation is attributed to long-range attractive forces originating from the substrate under the bubbles, which dominate the interaction at the bubble rim. The nonuniform bubble deformation leads to a nonuniform underestimation of the bubble height, width, and contact angle in conventional AFM height data. In particular, scanning with a hydrophobic tip resulted in severe bubble deformation and distorted information in the AFM height image. For a typical nanobubble, the upward deformation may extend up to tens of nanometers above the unperturbed bubble height, and the lateral deformation may constitute 20% of the bubble width. Therefore, only scanning with a hydrophilic tip and no direct contact between the tip and the bubble may reduce nanobubble deformation and provide reliable AFM images that can be used to estimate adequately the unperturbed nanobubble dimensions. The deformation of the bubble shape and underestimation of the bubble size lead to the conclusion that the profile of surface nanobubbles is much closer than previously thought to a nearly flat bubble profile and hence that the Laplace pressure is much closer to the atmospheric pressure. Together with line pinning, this may explain the long nanobubble lifetimes observed previously. The findings presented in this report hold independently of the material that constitutes the interrogated nanoscale surface features.
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Affiliation(s)
- Wiktoria Walczyk
- Physical Chemistry I, Department of Chemistry and Biology, University of Siegen , Adolf-Reichwein-Str. 2, 57076 Siegen, Germany
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