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Heima Y, Teshima H, Takahashi K. Nanoscale Contact Line Pinning Boosted by Ångström-Scale Surface Heterogeneity. J Phys Chem Lett 2023; 14:3561-3566. [PMID: 37017443 DOI: 10.1021/acs.jpclett.3c00428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
The pinning effect plays an important role in many fluidic systems but remains poorly understood, especially at the nanoscale. In this study, we measured the contact angles of glycerol nanodroplets on three different substrates using atomic force microscopy. By comparison of the shapes of the three-dimensional images of droplets, we found that a possible origin of the long-discussed deviation of the contact angles of nanodroplets from the macroscopic value is the pinning force induced by ångström-scale surface heterogeneity. It was also revealed that the pinning forces acting on glycerol nanodroplets on a silicon dioxide surface are up to twice as large as those acting on macroscale droplets. On a substrate where the effect of pinning was strong, an unexpected irreversible change from an irregularly shaped droplet to an atomically flat liquid film occurred. This was explained by the transition of the dominant force from liquid/gas interfacial tension to an adsorption force.
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Affiliation(s)
- Yuta Heima
- Department of Aeronautics and Astronautics, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Hideaki Teshima
- Department of Aeronautics and Astronautics, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
- International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Koji Takahashi
- Department of Aeronautics and Astronautics, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
- International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
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2
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Li D, Gu J, Li Y, Zhang Z, Ji Y. Manipulating Trapped Nanobubbles Moving and Coalescing with Surface Nanobubbles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:12991-12998. [PMID: 36228139 DOI: 10.1021/acs.langmuir.2c02593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Trapped nanobubbles are observed nucleating at nanopits on a pitted substrate, while surface nanobubbles are usually formed on the smooth solid surface in water. In this work, trapped nanobubbles and surface nanobubbles were captured by a tapping-mode atomic force microscope (AFM) on a nanopitted substrate based on the temperature difference method. A single trapped nanobubble was manipulated to change into a surface nanobubble, then to change into the trapped nanobubble again. At the same time, surface nanobubbles can be moved to merge into a trapped nanobubble. Our results show that the scan load and the size of the scan area were the main factors that significantly affect the mobility of surface/trapped nanobubbles. The coalescence and mutual transformation of the two kinds of nanobubbles indicate that trapped nanobubbles and surface nanobubbles have the same chemical nature, which also provides vital experimental proof of the existence of nanobubbles in the course of contact line depinning. Our results are of great significance for understanding nanobubble stability and providing guidelines in some industrial applications.
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Affiliation(s)
- Dayong Li
- School of Electromechanical and Automotive Engineering, Yantai University, Yantai 264005, China
| | - Juan Gu
- School of Mathematics and Information Science, Yantai University, Yantai 264005, China
| | - Yong Li
- School of Electromechanical and Automotive Engineering, Yantai University, Yantai 264005, China
| | - Ziqun Zhang
- School of Electromechanical and Automotive Engineering, Yantai University, Yantai 264005, China
| | - Yutong Ji
- School of Electromechanical and Automotive Engineering, Yantai University, Yantai 264005, China
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3
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Cross-sectional Observation of Micro- and Nanobubbles Formed <i>In-situ</i> in a Scanning Electron Microscope. E-JOURNAL OF SURFACE SCIENCE AND NANOTECHNOLOGY 2022. [DOI: 10.1380/ejssnt.2022-036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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4
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Teshima H, Kusudo H, Bistafa C, Yamaguchi Y. Quantifying interfacial tensions of surface nanobubbles: How far can Young's equation explain? NANOSCALE 2022; 14:2446-2455. [PMID: 35098963 DOI: 10.1039/d1nr07428h] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Nanobubbles at solid-liquid interfaces play a key role in various physicochemical phenomena and it is crucial to understand their unique properties. However, little is known about their interfacial tensions due to the lack of reliable calculation methods. Based on mechanical and thermodynamic insights, we quantified for the first time the liquid-gas, solid-liquid, and solid-gas interfacial tensions of submicron-sized nitrogen bubbles at graphite-water interfaces using molecular dynamics (MD) analysis. It was revealed that Young's equation holds even for nanobubbles with different radii. We found that the liquid-gas and solid-liquid interfacial tensions were not largely affected by the gas density inside the nanobubbles. In contrast, the size effect on the solid-gas interfacial tension was observed, namely, the value dramatically decreased upon an increase in the gas density due to gas adsorption on the solid surface. However, our quantitative evaluation also revealed that the gas density effect on the contact angles is negligible when the footprint radius is larger than 50 nm, which is a typical range observed in experiments, and thus the flat shape and stabilization of submicron-sized surface bubbles observed in experiments cannot be explained only by the changes in interfacial tensions due to the van der Waals interaction-induced gas adsorption, namely by Young's equation without introducing the pinning effect. Based on our analysis, it was clarified that additional factors such as the differences in the studied systems are needed to explain the unresolved open issues - a satisfactory explanation for the nanobubbles in MD simulations being ultradense, non-flat, and stable without pinning.
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Affiliation(s)
- Hideaki Teshima
- Department of Aeronautics and Astronautics, Kyushu University, Nishi-Ku, Motooka 744, Fukuoka 819-0395, Japan.
- International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Nishi-Ku, Motooka 744, Fukuoka 819-0395, Japan
| | - Hiroki Kusudo
- Department of Mechanical Engineering, Osaka University, 2-1 Yamadaoka, Suita, 565-0871, Japan
| | - Carlos Bistafa
- Department of Mechanical Engineering, Osaka University, 2-1 Yamadaoka, Suita, 565-0871, Japan
| | - Yasutaka Yamaguchi
- Department of Mechanical Engineering, Osaka University, 2-1 Yamadaoka, Suita, 565-0871, Japan
- Water Frontier Research Center (WaTUS), Tokyo University of Science, Shinjuku-Ku, Kagurazaka 1-3, 162-8601, Japan
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5
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Nag S, Tomo Y, Teshima H, Takahashi K, Kohno M. Dynamic interplay between interfacial nanobubbles: oversaturation promotes anisotropic depinning and bubble coalescence. Phys Chem Chem Phys 2021; 23:24652-24660. [PMID: 34704571 DOI: 10.1039/d1cp03451k] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Probing the dynamics of nanobubbles is essential to understand their longevity and behavior. Importantly, such an observation requires tools and techniques having high temporal resolutions to capture the intrinsic characteristics of the nanobubbles. In this work, we have used the in situ liquid-phase electron microscopy (LPEM) technique to gain insights into nanobubbles' behavior and their interfacial dynamics. Interestingly, we could observe a freely growing-shrinking nanobubble and a pinned nanobubble under the same experimental conditions, suggesting the possibility of multiple nanobubble stabilization theories and pathways. Remarkably, the study reveals that a freely growing-shrinking nanobubble induces anisotropic depinning in the three-phase contact line of a strongly pinned neighboring nanobubble. The anisotropic depinning is attributed to the differential local gas saturation levels, depending on the relative positioning of the freely growing-shrinking nanobubble. Furthermore, we also observed a unique pull-push phenomenon exhibited by the nanobubble's interfaces, which is attributed to the van der Waals interactions and the electric double layer collectively. The role of the electric double layer in suppressing and delaying the merging is also highlighted in this study. The present work aims to reveal the role of locally varying gas saturation in the depinning of nanobubbles, their longevity due to the electric double layer, and the consequent coalescence, which is crucial to understand the behavior of the nanobubbles. Our findings will essentially contribute to the understanding of these novel nanoscale gaseous domains and their dynamics.
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Affiliation(s)
- Sarthak Nag
- Department of Mechanical Engineering, Kyushu University, Fukuoka 819-0395, Japan. .,International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395, Japan
| | - Yoko Tomo
- Department of Mechanical Engineering, Kyushu University, Fukuoka 819-0395, Japan.
| | - Hideaki Teshima
- International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395, Japan.,Department of Aeronautics and Astronautics, Kyushu University, Fukuoka 819-0395, Japan
| | - Koji Takahashi
- International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395, Japan.,Department of Aeronautics and Astronautics, Kyushu University, Fukuoka 819-0395, Japan
| | - Masamichi Kohno
- Department of Mechanical Engineering, Kyushu University, Fukuoka 819-0395, Japan. .,International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395, Japan
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6
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Ma Y, Guo Z, Chen Q, Zhang X. Dynamic Equilibrium Model for Surface Nanobubbles in Electrochemistry. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:2771-2779. [PMID: 33576638 DOI: 10.1021/acs.langmuir.0c03537] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Gas bubbles are ubiquitous in electrochemical processes, particularly in water electrolysis. Due to the development of gas-evolving electrocatalysis and energy conversion technology, a deep understanding of gas bubble behaviors at the electrode surface is highly desirable. In this work, by combining theoretical analysis and molecular simulations, we study the behaviors of a single nanobubble electrogenerated at a nanoelectrode. With the dynamic equilibrium model, the stability criteria for stationary surface nanobubbles are established. We show theoretically that a slight change in either the gas solubility or solute concentration results in various nanobubble dynamic states at a nanoelectrode: contact line pinning in aqueous and ethylene glycol solutions, oscillation of pinning states in dimethyl sulfoxide, and mobile nanobubbles in methanol. The above complex nanobubble behavior at the electrode/electrolyte interface is explained by the competition between gas influx into the nanobubble and outflux from the nanobubble.
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Affiliation(s)
- Yunqing Ma
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China
| | - Zhenjiang Guo
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China
- Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China
| | - Qianjin Chen
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, China
| | - Xianren Zhang
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China
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7
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Nag S, Tomo Y, Takahashi K, Kohno M. Mechanistic Insights into Nanobubble Merging Studied Using In Situ Liquid-Phase Electron Microscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:874-881. [PMID: 33400870 DOI: 10.1021/acs.langmuir.0c03208] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Nanobubbles have attracted great interest in recent times because of their application in water treatment, surface cleaning, and targeted drug delivery, yet the challenge remains to gain thorough understanding of their unique behavior and dynamics for their utilization in numerous potential applications. In this work, we have used a liquid-phase electron microscopy technique to gain insights into the quasistatic merging of surface nanobubbles. The electron beam environment was controlled in order to suppress any new nucleation and slow down the merging process. The transmission electron microscopy study reveals that merging of closely positioned surface nanobubbles is initiated by gradual localized changes in the physical properties of the region between the adjoining nanobubble boundary. The observed phenomenon is then analyzed and discussed based on the different perceptions: localized liquid density gradient and bridge formation for gas exchange. In this study, it is estimated that the merging of the stable nanobubbles is initiated by the formation of a thin gas layer. This work not only enhances our understanding of the merging process of stable surface nanobubbles but will also lead to exploration of new domains for nanobubble applications.
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Affiliation(s)
- Sarthak Nag
- Department of Mechanical Engineering, Kyushu University, Fukuoka 819-0395, Japan
- International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395, Japan
| | - Yoko Tomo
- Department of Mechanical Engineering, Kyushu University, Fukuoka 819-0395, Japan
| | - Koji Takahashi
- Department of Aeronautics and Astronautics, Kyushu University, Fukuoka 819-0395, Japan
- International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395, Japan
| | - Masamichi Kohno
- Department of Mechanical Engineering, Kyushu University, Fukuoka 819-0395, Japan
- International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395, Japan
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8
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Ramazanov S, Sobola D, Orudzhev F, Knápek A, Polčák J, Potoček M, Kaspar P, Dallaev R. Surface Modification and Enhancement of Ferromagnetism in BiFeO 3 Nanofilms Deposited on HOPG. NANOMATERIALS (BASEL, SWITZERLAND) 2020; 10:E1990. [PMID: 33050330 PMCID: PMC7600225 DOI: 10.3390/nano10101990] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 09/30/2020] [Accepted: 10/07/2020] [Indexed: 11/16/2022]
Abstract
BiFeO3 (BFO) films on highly oriented pyrolytic graphite (HOPG) substrate were obtained by the atomic layer deposition (ALD) method. The oxidation of HOPG leads to the formation of bubble regions creating defective regions with active centers. Chemisorption occurs at these active sites in ALD. Additionally, carbon interacts with ozone and releases carbon oxides (CO, CO2). Further annealing during the in situ XPS process up to a temperature of 923 K showed a redox reaction and the formation of oxygen vacancies (Vo) in the BFO crystal lattice. Bubble delamination creates flakes of BiFeO3-x/rGO heterostructures. Magnetic measurements (M-H) showed ferromagnetism (FM) at room temperature Ms ~ 120 emu/cm3. The contribution to magnetization is influenced by the factor of charge redistribution on Vo causing the distortion of the lattice as well as by the superstructure formed at the boundary of two phases, which causes strong hybridization due to the superexchange interaction of the BFO film with the FM sublattice of the interface region. The development of a method for obtaining multiferroic structures with high FM values (at room temperature) is promising for magnetically controlled applications.
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Affiliation(s)
- Shikhgasan Ramazanov
- Faculty of Physics, Dagestan State University, Makhachkala, St. M. Gadjieva 43-a, 367015 Makhachkala, Russia;
| | - Dinara Sobola
- Department of Physics, Faculty of Electrical Engineering and Communication, Brno University of Technology, Technicka 2848/8, 61600 Brno, Czech Republic; (D.S.); (R.D.)
- Central European Institute of Technology, Brno University of Technology, Purkyňova 123, 612 00 Brno, Czech Republic; (J.P.); (M.P.)
- Department of Inorganic Chemistry and Chemical Ecology, Dagestan State University, Makhachkala, St. M. Gadjieva 43-a, 367015 Makhachkala, Russia;
| | - Farid Orudzhev
- Department of Inorganic Chemistry and Chemical Ecology, Dagestan State University, Makhachkala, St. M. Gadjieva 43-a, 367015 Makhachkala, Russia;
| | - Alexandr Knápek
- Institute of the Scientific Instruments of the Czech Academy of Sciences v.v.i., Královopolská 147, 61264 Brno, Czech Republic;
| | - Josef Polčák
- Central European Institute of Technology, Brno University of Technology, Purkyňova 123, 612 00 Brno, Czech Republic; (J.P.); (M.P.)
- Institute of Physical Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Technicka 2896/2, 61669 Brno, Czech Republic
| | - Michal Potoček
- Central European Institute of Technology, Brno University of Technology, Purkyňova 123, 612 00 Brno, Czech Republic; (J.P.); (M.P.)
- Institute of Physical Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Technicka 2896/2, 61669 Brno, Czech Republic
| | - Pavel Kaspar
- Department of Physics, Faculty of Electrical Engineering and Communication, Brno University of Technology, Technicka 2848/8, 61600 Brno, Czech Republic; (D.S.); (R.D.)
| | - Rashid Dallaev
- Department of Physics, Faculty of Electrical Engineering and Communication, Brno University of Technology, Technicka 2848/8, 61600 Brno, Czech Republic; (D.S.); (R.D.)
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9
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Yen TH. Influence of gas aggregation on water-solid interface: molecular simulation. MOLECULAR SIMULATION 2020. [DOI: 10.1080/08927022.2020.1828881] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Tsu-Hsu Yen
- Department of Marine Science, R.O.C. Naval Academy, Kaohsiung, Taiwan, Republic of China (R.O.C.)
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10
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Hirokawa S, Teshima H, Solís-Fernández P, Ago H, Tomo Y, Li QY, Takahashi K. Nanoscale Bubble Dynamics Induced by Damage of Graphene Liquid Cells. ACS OMEGA 2020; 5:11180-11185. [PMID: 32455241 PMCID: PMC7241020 DOI: 10.1021/acsomega.0c01207] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 04/24/2020] [Indexed: 05/13/2023]
Abstract
Graphene liquid cells provide the highest possible spatial resolution for liquid-phase transmission electron microscopy. Here, in graphene liquid cells (GLCs), we studied the nanoscale dynamics of bubbles induced by controllable damage in graphene. The extent of damage depended on the electron dose rate and the presence of bubbles in the cell. After graphene was damaged, air leaked from the bubbles into the water. We also observed the unexpected directional nucleation of new bubbles, which is beyond the explanation of conventional diffusion theory. We attributed this to the effect of nanoscale confinement. These findings provide new insights into complex fluid phenomena under nanoscale confinement.
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Affiliation(s)
- Sota Hirokawa
- Department
of Aeronautics and Astronautics, Kyushu
University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Hideaki Teshima
- Department
of Aeronautics and Astronautics, Kyushu
University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
- International
Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Pablo Solís-Fernández
- Global
Innovation Center, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580, Japan
| | - Hiroki Ago
- Global
Innovation Center, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580, Japan
| | - Yoko Tomo
- Department
of Mechanical Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Qin-Yi Li
- Department
of Aeronautics and Astronautics, Kyushu
University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
- International
Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Koji Takahashi
- Department
of Aeronautics and Astronautics, Kyushu
University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
- International
Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
- . Tel: +81-92-802-3015
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11
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Abstract
This review starts with the main process of fog collection and then analyzes the influencing factors that affect the efficiency of fog collection.
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Affiliation(s)
- Xing Tang
- Hubei Collaborative Innovation Centre for Advanced Organic Chemical Materials and Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials
- Hubei University
- Wuhan 430062
- People's Republic of China
- State Key Laboratory of Solid Lubrication
| | - Zhiguang Guo
- Hubei Collaborative Innovation Centre for Advanced Organic Chemical Materials and Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials
- Hubei University
- Wuhan 430062
- People's Republic of China
- State Key Laboratory of Solid Lubrication
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12
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Teshima H, Nakamura N, Li QY, Takata Y, Takahashi K. Zigzag gas phases on holey adsorbed layers. RSC Adv 2020; 10:44854-44859. [PMID: 35516233 PMCID: PMC9058577 DOI: 10.1039/d0ra08861g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Accepted: 11/30/2020] [Indexed: 12/28/2022] Open
Abstract
We report for the first time a zigzag-shaped gas phase at a highly-ordered pyrolytic graphite/water interface. The novel shape of the gaseous domain is triggered by the holes of the underlying solid-like layers, which are composed of air molecules. Specifically, many holes were created by heating in the thin solid-like layers, which roughened them. The gas domains that formed on these layers deformed from circular to zigzag-shaped as the contact lines expanded while avoiding the holes of the underlying layers. We explained the formation and growth processes of these gas structures in terms of thin film growth, which varies with the mobility of the constituent molecules. Heating induces the formation of novel zigzag gas phases on the holey adsorbed air layers.![]()
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Affiliation(s)
- Hideaki Teshima
- Department of Aeronautics and Astronautics
- Kyushu University
- Fukuoka 819-0395
- Japan
- Department of Mechanical Engineering
| | - Naoto Nakamura
- Department of Aeronautics and Astronautics
- Kyushu University
- Fukuoka 819-0395
- Japan
| | - Qin-Yi Li
- Department of Aeronautics and Astronautics
- Kyushu University
- Fukuoka 819-0395
- Japan
- International Institute for Carbon-Neutral Energy Research (WPI-I2CNER)
| | - Yasuyuki Takata
- International Institute for Carbon-Neutral Energy Research (WPI-I2CNER)
- Kyushu University
- Fukuoka 819-0395
- Japan
- Department of Mechanical Engineering
| | - Koji Takahashi
- Department of Aeronautics and Astronautics
- Kyushu University
- Fukuoka 819-0395
- Japan
- International Institute for Carbon-Neutral Energy Research (WPI-I2CNER)
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13
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Li QY, Matsushita R, Tomo Y, Ikuta T, Takahashi K. Water Confined in Hydrophobic Cup-Stacked Carbon Nanotubes beyond Surface-Tension Dominance. J Phys Chem Lett 2019; 10:3744-3749. [PMID: 31244269 DOI: 10.1021/acs.jpclett.9b00718] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Water confined in carbon nanotubes (CNTs) can exhibit distinctly different behaviors from the bulk. We report transmission electron microscopy (TEM) observation of water phases inside hydrophobic cup-stacked CNTs exposed to high vacuum. Unexpectedly, we observed stable water morphologies beyond surface-tension dominance, including nanometer thin free water films, complex water-bubble structures, and zigzag-shaped liquid-gas interface. The menisci of the water phases are complex and inflected, where we measured the contact angles on the CNT inner wall to be 68-104°. The superstability of the suspended ultrathin water films is attributed to the strong hydrogen-bonded network among water molecules and adsorption of water molecules on the cup-structured inner wall. The complex water-bubble structure is a result of the stability of free water films and interfacial nanobubbles, and the zigzag edge of the liquid-gas interface is explained by the pinning effect. These experimental findings provide valuable knowledge for the research on fluids under nanoscale confinement.
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Affiliation(s)
- Qin-Yi Li
- Department of Aeronautics and Astronautics , Kyushu University , Fukuoka 819-0395 , Japan
- International Institute for Carbon Neutral Energy Research (WPI-I2CNER) , Kyushu University , Fukuoka 819-0395 , Japan
| | - Ryo Matsushita
- Department of Aeronautics and Astronautics , Kyushu University , Fukuoka 819-0395 , Japan
| | - Yoko Tomo
- Department of Aeronautics and Astronautics , Kyushu University , Fukuoka 819-0395 , Japan
| | - Tatsuya Ikuta
- Department of Aeronautics and Astronautics , Kyushu University , Fukuoka 819-0395 , Japan
- International Institute for Carbon Neutral Energy Research (WPI-I2CNER) , Kyushu University , Fukuoka 819-0395 , Japan
| | - Koji Takahashi
- Department of Aeronautics and Astronautics , Kyushu University , Fukuoka 819-0395 , Japan
- International Institute for Carbon Neutral Energy Research (WPI-I2CNER) , Kyushu University , Fukuoka 819-0395 , Japan
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14
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Zou J, Zhang H, Guo Z, Liu Y, Wei J, Huang Y, Zhang X. Surface Nanobubbles Nucleate Liquid Boiling. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:14096-14101. [PMID: 30380889 DOI: 10.1021/acs.langmuir.8b03290] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Surface nanobubbles have been presumed to lead to the experimental observation that liquid boiling often occurs at a much lower supersaturation than expected, yet no qualitative theory exists to explain how they participate in the process. Here, we report through a simple theoretical analysis on how the metastable nanobubbles nucleate the liquid-to-vapor transition by serving as an intermediate phase. The appearance of metastable nanobubbles inhibits the shrink of the bubble nucleus and changes bubble nucleation into a multistep process. We show three possible mechanisms for heterogeneous nucleation starting from metastable surface nanobubbles: nucleation from pinned nanobubbles, nucleation via nanobubble depinning, and nucleation through nanobubble coalescence, each predicting a significant reduction in a nucleation barrier. The occurrence of a specific nucleation pathway of bubble nucleation depends on the detailed geometry of local substrate roughness. These results give insight into how the appearance of surface nanobubbles changes the nucleation mechanisms of liquid boiling.
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Affiliation(s)
- Jintao Zou
- State Key Laboratory of Organic-Inorganic Composites , Beijing University of Chemical Technology , Beijing 100029 , China
| | - Hongguang Zhang
- State Key Laboratory of Organic-Inorganic Composites , Beijing University of Chemical Technology , Beijing 100029 , China
| | - 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
| | - Jiachen Wei
- State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics , Chinese Academy of Sciences , 15 Beisihuanxi Road , Beijing 100190 , China
- School of Engineering Science , University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Yan Huang
- 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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