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Manufacturing a TiO2-Based Semiconductor Film with Nanofluid Pool Boiling and Sintering Processes toward Solar-Cell Applications. NANOMATERIALS 2022; 12:nano12071165. [PMID: 35407284 PMCID: PMC9000513 DOI: 10.3390/nano12071165] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 03/10/2022] [Accepted: 03/18/2022] [Indexed: 12/10/2022]
Abstract
For the first time, nanofluid boiling was applied as a process for the creation of a semiconductor TiO2 nanoparticle film that can be deposited onto a conductive substrate (F-doped SnO2 glass: FTO). A steel-base device designed for pool boiling was used to deposit a TiO2-based nanofluid consisting of nanoparticles with an average size of about 20 nm. The boiling of the nanofluid directly on the FTO glass substrate allowed for the deposition of the nanoparticles onto the FTO surface. In principle, the surface responsible for transferring heat to the fluid can be covered with these nanoparticles when the nanofluid boils. Using the as-deposited films, crystal growth of the TiO2 nanoparticle was controlled by varying the strategies of the post-sintering profile. The maximum temperatures, periods, and ramping rates for the obtained samples were systematically changed. Scanning electron microscopy (SEM) revealed that a densely packed TiO2-nanoparticle layer was obtained for the as-deposited substrate via pool boiling. For the maximum temperature at 550 °C, the TiO2 grain sizes became larger (~50 nm) and more round-shaped TiO2 nanostructures were identified. Notably, we have demonstrated for the first time how the sintering of TiO2 nanoparticles proceeds for the nanoporous TiO2 films using high-resolution transmission electron microscopy (TEM) measurements. We found that the TiO2 nanoparticles fused with each other and crystal growth occurred through neighboring 2–4 nanoparticles for the 550 °C sample, which was proved by the TEM analysis that continuous lattice fringes corresponding to the (101) anatase phase were clearly observed through the entire area of some nanoparticles aligned horizontally. In addition, the loss of the TiO2 nanofluid (precursor solution) was completely avoided in our TiO2 deposition. Unlike the commonly used spin-coating method, nanofluid pool boiling would provide an alternative cost-effective approach to manufacture semiconductor layers for various applications, such as solar cells.
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Dousti A, Gharedaghi H, Hanafizadeh P, Ashjaee M. Different nanofluids effect on bubble characteristics at the isothermal bubble column. CAN J CHEM ENG 2021. [DOI: 10.1002/cjce.24047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Ahmad Dousti
- School of Mechanical Engineering, College of Engineering University of Tehran Tehran Iran
| | - Hamed Gharedaghi
- School of Mechanical Engineering, College of Engineering University of Tehran Tehran Iran
| | - Pedram Hanafizadeh
- School of Mechanical Engineering, College of Engineering University of Tehran Tehran Iran
| | - Mehdi Ashjaee
- School of Mechanical Engineering, College of Engineering University of Tehran Tehran Iran
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Importance of interfacial and rheological properties in the suppression of uniform deposition to coffee ring pattern of zinc oxide nanofluids in the presence of anionic surfactants. Colloid Polym Sci 2020. [DOI: 10.1007/s00396-020-04646-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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4
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Gharedaghi H, Dousti A, Eshraghi J, Hanafizadeh P, Ashjaee M. A novel numerical approach for investigation of the gas bubble characteristics in stagnant liquid using Young-Laplace equation. Chem Eng Sci 2017. [DOI: 10.1016/j.ces.2017.07.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Kibar A, Ozbay R, Sarshar MA, Kang YT, Choi CH. Bubble Movement on Inclined Hydrophobic Surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:12016-12027. [PMID: 28982237 DOI: 10.1021/acs.langmuir.7b02831] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The movement of a single air bubble on an inclined hydrophobic surface submerged in water, including both the upward- and downward-facing sides of the surface, was investigated. A planar Teflon sheet with an apparent contact angle of a sessile water droplet of 106° was used as a hydrophobic surface. The volume of a bubble and the inclination angle of a Teflon sheet varied in the ranges 5-40 μL and 0-45°, respectively. The effects of the bubble volume on the adhesion and dynamics of the bubble were studied experimentally on the facing-up and facing-down surfaces of the submerged hydrophobic Teflon sheet, respectively, and compared. The result shows that the sliding angle has an inverse relationship with the bubble volume for both the upward- and downward-facing surfaces. However, at the same given volume, the bubble on the downward-facing surface spreads over a larger area of the hydrophobic surface than the upward-facing surface due to the greater hydrostatic pressure acting on the bubble on the downward-facing surface. This makes the lateral adhesion force of the bubble greater and requires a larger inclination angle to result in sliding.
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Affiliation(s)
- Ali Kibar
- Department of Mechanical and Material Technologies, Kocaeli University , Arslanbey Campus, Kocaeli, 41285, Turkey
- Department of Mechanical Engineering, Stevens Institute of Technology , Hoboken, New Jersey 07030, United States
| | - Ridvan Ozbay
- Department of Mechanical Engineering, Stevens Institute of Technology , Hoboken, New Jersey 07030, United States
| | - Mohammad Amin Sarshar
- Department of Mechanical Engineering, Stevens Institute of Technology , Hoboken, New Jersey 07030, United States
| | - Yong Tae Kang
- School of Mechanical Engineering, Korea University , Seoul, 02841, Korea
| | - Chang-Hwan Choi
- Department of Mechanical Engineering, Stevens Institute of Technology , Hoboken, New Jersey 07030, United States
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Vafaei S, Chinnathambi K, Borca-Tasciuc T. Liquid–gas surface tension voltage dependence during electrowetting on dielectric testing of water and 5–90 nm gold nanofluids. J Colloid Interface Sci 2017. [DOI: 10.1016/j.jcis.2014.12.049] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Luo J, Du Z, Tai X, Wang W, Wu J, Ding B, Wang P. One-Pot Preparation of Nano-SiO2 Using a Silane Derivative as a Coupling Agent. TENSIDE SURFACT DET 2016. [DOI: 10.3139/113.110434] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
The nano-silica particles were prepared by one-pot method using absolute ethanol as solvent. After the nano-silica derived from TEOS was synthesized, the coupling agent was added into the above suspension without any filtration or purification processes to modify the nano SiO2. The optimum modification conditions were determined based on the degree of oil affinity and water sorption ratio. The size and morphology of SiO2 before and after modification were observed using Transmission Electron Microscopy. The introductions of the organic chains to their surfaces were measured using Ultraviolet and Visible Spectrophotometry, Fourier Transform Infrared Spectroscopy and 13C solid-state Nuclear Magnetic Resonance. The influences of the hydrophobicity of the organic functional group on the nano-silica particles were tested by the water contact angle. The results show that the organic chains had been grafted on the surface of nano-silica.
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Affiliation(s)
- Jianhui Luo
- Research Institute of Petroleum Exploration & Development , Petro China, Beijing , P. R. China
| | - Zhiping Du
- China Research Institute of Daily Chemical Industry , Taiyuan , P. R. China
- Resources and Environment Engineering Research Institute , Shanxi University, Taiyuan , P. R. China
| | - Xiumei Tai
- China Research Institute of Daily Chemical Industry , Taiyuan , P. R. China
| | - Wanxu Wang
- China Research Institute of Daily Chemical Industry , Taiyuan , P. R. China
| | - Jianghong Wu
- China Research Institute of Daily Chemical Industry , Taiyuan , P. R. China
| | - Bin Ding
- Research Institute of Petroleum Exploration & Development , Petro China, Beijing , P. R. China
| | - Pingmei Wang
- Research Institute of Petroleum Exploration & Development , Petro China, Beijing , P. R. China
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Vafaei S. Theoretical and experimental investigations of dynamics of bubble growth and triple line. CAN J CHEM ENG 2016. [DOI: 10.1002/cjce.22367] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Saeid Vafaei
- Department of Mechanical Engineering; Bradley University, IL; USA
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9
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Modification of the Young-Laplace equation and prediction of bubble interface in the presence of nanoparticles. Adv Colloid Interface Sci 2015; 225:1-15. [PMID: 26320606 DOI: 10.1016/j.cis.2015.07.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 05/10/2015] [Accepted: 07/20/2015] [Indexed: 10/23/2022]
Abstract
Bubbles are fundamental to our daily life and have wide applications such as in the chemical and petrochemical industry, pharmaceutical engineering, mineral processing and colloids engineering. This paper reviews the existing theoretical and experimental bubble studies, with a special focus on the dynamics of triple line and the influence of nanoparticles on the bubble growth and departure process. Nanoparticles are found to influence significantly the effective interfacial properties and the dynamics of triple line, whose effects are dependent on the particle morphology and their interaction with the substrate. While the Young-Laplace equation is widely applied to predict the bubble shape, its application is limited under highly non-equilibrium conditions. Using gold nanoparticle as an example, new experimental study is conducted to reveal the particle concentration influence on the behaviour of triple line and bubble dynamics. A new method is developed to predict the bubble shape when the interfacial equilibrium conditions cannot be met, such as during the oscillation period. The method is used to calculate the pressure difference between the gas and liquid phases, which is shown to oscillate across the liquid-gas interface and is responsible for the interface fluctuation. The comparison of the theoretical study with the experimental data shows a very good agreement, which suggests its potential application to predict bubble shape during non-equilibrium conditions.
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Shu GG, Xu Q, Wu P. Study of wetting on chemically soften interfaces by using combined solution thermodynamics and DFT calculations: forecasting effective softening elements. ACS APPLIED MATERIALS & INTERFACES 2015; 7:7576-7583. [PMID: 25844936 DOI: 10.1021/am509013m] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Despite recent progress in understanding the wetting principles on soft solids, the roles of chemical bonding in the formation of interfaces have been largely ignored, because most of these studies are conducted at room temperatures. Here we propose a universal wetting principle from solution thermodynamics to account for the softening of both the solid and liquid surfaces (stable or metastable). Density functional theory (DFT) calculations are applied to evaluate the stability and electron transportation across the interfaces. We find that wetting is dominated by the system entropy changes involving not only the stable liquid alloy phase but also the metastable liquid oxide phases. The state-of-art multicomponent solution thermodynamic models and databases are applied to describe the entropy changes and predict the wetting behaviors. Our results show that by chemically softening either the liquid or the solid phase, the wetting angle reduces. And an effective soften agent/additive (either in the form of chemical elements or molecules) will weaken the bonds within the liquid (or solid) phase and promote new bonds at the interfaces, thus increasing the interface entropy. Subsequently, as an example, Ti and Zr are proposed as effective softening elements to improve the wetting of aluminum liquid on B6Si(s). This approach provides a concept and tool to advance research in catalytic chemistry, nucleation (growth), elastowetting, and cell-substrate interactions.
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Affiliation(s)
- Guo Gang Shu
- †Nuclear Materials Joint Lab, Tsinghua University Graduate School, Tsinghua University City Park, Shenzhen 518055, China
| | - Qiang Xu
- ‡Entropic Interface Group, Engineering Product Development, Singapore University of Technology and Design, 8 Somapah Road, Singapore 487372, Singapore
| | - Ping Wu
- ‡Entropic Interface Group, Engineering Product Development, Singapore University of Technology and Design, 8 Somapah Road, Singapore 487372, Singapore
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Vafaei S, Wen D. Critical heat flux of nanofluids inside a single microchannel: Experiments and correlations. Chem Eng Res Des 2014. [DOI: 10.1016/j.cherd.2014.02.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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12
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Vafaei S, Borca-Tasciuc T. Role of nanoparticles on nanofluid boiling phenomenon: Nanoparticle deposition. Chem Eng Res Des 2014. [DOI: 10.1016/j.cherd.2013.08.007] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Milne AJB, Amirfazli A. The Cassie equation: how it is meant to be used. Adv Colloid Interface Sci 2012; 170:48-55. [PMID: 22257682 DOI: 10.1016/j.cis.2011.12.001] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Revised: 12/06/2011] [Accepted: 12/06/2011] [Indexed: 11/28/2022]
Abstract
A review of literature shows that the majority of papers cite a potentially incorrect form of the Cassie and Cassie-Baxter equations to interpret or predict contact angle data. We show that for surfaces wet with a composite interface, the commonly used form of the Cassie-Baxter equation, cosθ(c)=f(1)cosθ-(1-f), is only correct for the case of flat topped pillar geometry without any penetration of the liquid. In general, the original form of the Cassie-Baxter equation, cosθ(c)=f(1)cosθ(1)-f(2), with f(1)+f(2)≥1, should be used. The differences between the two equations are discussed and the errors involved in using the incorrect equation are estimated to be between ~3° and 13° for superhydrophobic surfaces. The discrepancies between the two equations are also discussed for the case of a liquid undergoing partial, but increasing, levels of penetration. Finally, a general equation is presented for the transition/stability criterion between the Cassie-Baxter and Wenzel modes of wetting.
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Affiliation(s)
- A J B Milne
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 2G8
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Vafaei S, Wen D. Spreading of triple line and dynamics of bubble growth inside nanoparticle dispersions on top of a substrate plate. J Colloid Interface Sci 2011; 362:285-91. [DOI: 10.1016/j.jcis.2011.06.048] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Revised: 06/16/2011] [Accepted: 06/17/2011] [Indexed: 11/28/2022]
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15
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Preparation and characterization of surface modified silica nanoparticles with organo-silane compounds. Colloids Surf A Physicochem Eng Asp 2011. [DOI: 10.1016/j.colsurfa.2011.04.010] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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16
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Vafaei S, Wen D, Borca-Tasciuc T. Nanofluid surface wettability through asymptotic contact angle. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:2211-2218. [PMID: 21338112 DOI: 10.1021/la104254a] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
This investigation introduces the asymptotic contact angle as a criterion to quantify the surface wettability of nanofluids and determines the variation of solid surface tensions with nanofluid concentration and nanoparticle size. The asymptotic contact angle, which is only a function of gas-liquid-solid physical properties, is independent of droplet size for ideal surfaces and can be obtained by equating the normal component of interfacial force on an axisymmetric droplet to that of a spherical droplet. The technique is illustrated for a series of bismuth telluride nanofluids where the variation of surface wettability is measured and evaluated by asymptotic contact angles as a function of nanoparticle size, concentration, and substrate material. It is found that the variation of nanofluid concentration, nanoparticle size, and substrate modifies both the gas-liquid and solid surface tensions, which consequently affects the force balance at the triple line, the contact angle, and surface wettability.
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Affiliation(s)
- Saeid Vafaei
- School of Engineering and Materials Science, Queen Mary University of London, London, United Kingdom
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Chen HJ, Wen D. Ultrasonic-aided fabrication of gold nanofluids. NANOSCALE RESEARCH LETTERS 2011; 6:198. [PMID: 21711710 PMCID: PMC3211254 DOI: 10.1186/1556-276x-6-198] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Accepted: 03/07/2011] [Indexed: 05/30/2023]
Abstract
A novel ultrasonic-aided one-step method for the fabrication of gold nanofluids is proposed in this study. Both spherical- and plate-shaped gold nanoparticles (GNPs) in the size range of 10-300 nm are synthesized. Subsequent purification produces well-controlled nanofluids with known solid and liquid contents. The morphology and properties of the nanoparticle and nanofluids are characterized by transmission electron microscopy, scanning electron microscope, energy dispersive X-ray spectroscope, X-ray diffraction spectroscopy, and dynamic light scattering, as well as effective thermal conductivities. The ultrasonication technique is found to be a very powerful tool in engineering the size and shape of GNPs. Subsequent property measurement shows that both particle size and particle shape play significant roles in determining the effective thermal conductivity. A large increase in effective thermal conductivity can be achieved (approximately 65%) for gold nanofluids using plate-shaped particles under low particle concentrations (i.e.764 μM/L).
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Affiliation(s)
- Hui-Jiuan Chen
- School of Engineering and Materials Science, Queen Mary University of London, London, UK
| | - Dongsheng Wen
- School of Engineering and Materials Science, Queen Mary University of London, London, UK
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Haustrup N, O’Connor G. Nanoparticle Generation During Laser Ablation and Laser-Induced Liquefaction. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/j.phpro.2011.03.104] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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