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Chen C, Liu J, Liu Y, Peng X. Simulation investigation of the spontaneous motion behaviors of underwater oil droplets on a conical surface. SOFT MATTER 2022; 18:9172-9180. [PMID: 36444757 DOI: 10.1039/d2sm00937d] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
A conical surface can realize the spontaneous transportation of micro-sized oil droplets in an aqueous environment without energy input, exhibiting great potential for applications in microfluidics, chemical micro-reactors, water remediation, etc. However, the precise manipulation of an oil droplet on a cone is still very challenging because the dynamic behavior of a droplet on a cone is not fully understood. Herein, the dynamic behavior of oil droplets on a cone is quantitively studied via numerical simulations, and the effects of wettability, apex angle, and droplet size on the droplet's dynamic behavior are systematically analyzed. The results show that the moving velocity and transport distance of the droplet on the cone are highly related to the droplet shape on the cone. It was found that a clamshell-shaped droplet moves faster than a barrel-shaped droplet. Besides, the clamshell-shaped droplet with a larger size, on the cone with a smaller apex angle and smaller contact angle tends to obtain a faster moving speed and a longer transportation distance. The droplet shape adopted on the cone was determined by the cone wettability and the size of the droplet relative to the local curvature of the cone. It was found that the oil droplet tends to form a barrel shape on the cone with a highly oleophilic and small apex angle, and tends to form a clamshell shape on cones with a highly oleophobic and large apex angle. In addition, the droplet might transit from a barrel shape to a clamshell shape when it moves from the cone tip to the cone base, and the trigger time of the transit is negatively correlated with the contact angle and apex angle of the cone. This work provides a microscale understanding of the dynamic behavior of an underwater oil droplet on a cone, and also offers theoretical guidance for manipulating the behavior of a droplet on a cone and for the rational design of cone surfaces for spontaneous droplet transport and droplet collection.
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Affiliation(s)
- Chaolang Chen
- School of Mechanical Engineering, Sichuan University, Chengdu 610065, China.
| | - Jian Liu
- School of Mechanical Engineering, Sichuan University, Chengdu 610065, China.
| | - Yangkai Liu
- School of Mechanical Engineering, Sichuan University, Chengdu 610065, China.
| | - Xuqiao Peng
- School of Mechanical Engineering, Sichuan University, Chengdu 610065, China.
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Liu C, Liu X, Tang Q, Zhou W, Ma Y, Gong Z, Chen J, Zheng H, Joo SW. Three-Dimensional Droplet Manipulation with Electrostatic Levitation. Anal Chem 2022; 94:8217-8225. [PMID: 35622947 DOI: 10.1021/acs.analchem.2c00178] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An active and precise method for three-dimensional (3D) droplet manipulation is introduced. By modulating the local electrostatic force acting on droplets in carrier oil between needle plate electrodes, the vertical motion of droplets can be controlled, including the droplet levitation at the interface between the carrier oil and the air. Levitated droplets can be translated horizontally with high efficiency by the motion of the needle electrode. With controllable local deformation on the flexible plate electrode, selective manipulation can be realized for multiple droplets. Applying the manipulation method proposed, a platform is built and various droplet handling, such as transport, merging, and mixing, is performed effectively. Complex droplet transport trajectories are achieved by moving the needle electrode. The droplet transport velocity can reach up to 37 mm/s. The introduced method has fundamental advantages of avoiding cross-contamination between droplets, enhancing the flexibility, eliminating the transport track constraint, and lowering costs with straightforward and precise droplet manipulation.
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Affiliation(s)
- Chang Liu
- School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China
| | - Xiaofeng Liu
- School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China
| | - Qiang Tang
- The Institute of Technological Sciences, Wuhan University, Wuhan 430072, China
| | - Wenhao Zhou
- School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China
| | - Yan Ma
- School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China
| | - Zheng Gong
- School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China
| | - Junhao Chen
- School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China
| | - Huai Zheng
- School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China.,The Institute of Technological Sciences, Wuhan University, Wuhan 430072, China
| | - Sang Woo Joo
- School of Mechanical Engineering, Yeungnam University, Gyeongsan 38541, South Korea
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Monga D, Guo Z, Shan L, Taba SA, Sarma J, Dai X. Quasi-Liquid Surfaces for Sustainable High-Performance Steam Condensation. ACS APPLIED MATERIALS & INTERFACES 2022; 14:13932-13941. [PMID: 35287435 DOI: 10.1021/acsami.2c00401] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Sustainable high-performance steam condensation is critical to reducing the size, weight, and cost of water and energy systems. It is well-known that dropwise condensation can provide a significantly higher heat-transfer coefficient than filmwise condensation. Tremendous efforts have been spent to promote dropwise condensation by achieving a nonwetting state on superhydrophobic surfaces and a slippery state on liquid-infused surfaces, but these surfaces suffer from severe durability challenges. Here, we report sustainable high-performance dropwise condensation of steam on newly developed durable quasi-liquid surfaces, which are easily made by chemically bonding quasi-liquid polymer molecules on solid substrates. As a result, the solid/water interface is changed to a quasi-liquid/water interface with minimal adhesion and extraordinary durability. The quasi-liquid surface with ultralow contact angle hysteresis down to 1° showed a heat-transfer coefficient up to 70 and 380% higher than those on conventional hydrophobic and hydrophilic surfaces, respectively. Furthermore, we demonstrated that the quasi-liquid coating exhibited a sustainable heat-transfer coefficient of 71 kW/(m2 K) at a heat flux of 420 kW/m2 under a prolonged period of 39 h in continuous steam condensation. Such a quasi-liquid surface has the potential to sustain high-performance dropwise condensation of steam and address the long-standing durability challenge in the field.
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Affiliation(s)
- Deepak Monga
- Department of Mechanical Engineering, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Zongqi Guo
- Department of Mechanical Engineering, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Li Shan
- Department of Mechanical Engineering, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Seyed Adib Taba
- Department of Mechanical Engineering, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Jyotirmoy Sarma
- Department of Mechanical Engineering, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Xianming Dai
- Department of Mechanical Engineering, The University of Texas at Dallas, Richardson, Texas 75080, United States
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Tang Q, Liu X, Cui X, Su Z, Zheng H, Tang J, Joo SW. Contactless Discharge-Driven Droplet Motion on a Nonslippery Polymer Surface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:14697-14702. [PMID: 34894688 DOI: 10.1021/acs.langmuir.1c02462] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Droplet manipulation is the cornerstone of many modern technologies. It is still challenging to drive the droplet motion on nonslippery surfaces flexibly. We present a droplet manipulation method on nonslippery polymer surfaces based on the corona discharge. With the corona discharge of two-needle electrodes with opposite polarities, the droplet's charge polarity can be switched, which results in the directionally droplet transport on a charged polymer surface with the oscillation. Here, such droplet behaviors are presented in detail. Dependence of the motion on the critical distance and driving distance between the droplet and the needle electrode is revealed. The driving mechanism is verified by experiments and simulations. This work enriches the droplet manipulation techniques on nonslippery surfaces for various applications, such as combinatory chemistry, biochemical, and medical detection.
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Affiliation(s)
- Qiang Tang
- The Institute of Technological Sciences, Wuhan University, Wuhan 430072, China
| | - Xiaofeng Liu
- School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China
| | - Xiaxia Cui
- The Institute of Technological Sciences, Wuhan University, Wuhan 430072, China
| | - Zhenpeng Su
- School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China
| | - Huai Zheng
- The Institute of Technological Sciences, Wuhan University, Wuhan 430072, China
- School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China
| | - Jau Tang
- The Institute of Technological Sciences, Wuhan University, Wuhan 430072, China
| | - Sang Woo Joo
- School of Mechanical Engineering, Yeungnam University, Gyeongsan 38541, South Korea
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Liang X, Li D, Li S, Xu C, Guo Z. Artificial Leaf for Switchable Droplet Manipulation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:5745-5752. [PMID: 33929871 DOI: 10.1021/acs.langmuir.1c00799] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Droplet manipulation plays an important role in scientific research, daily life, and practical production such as biological and chemical analysis. Inspired by the structure and function of three typical leaf veins, the bionic texture was replicated by the template method, and the artificial leaf was selectively treated by nanoparticles to obtain a quasi-three-dimensional hybrid superhydrophobic-hydrophilic surface. When the droplet touches the surface of the leaf, it will be attracted to the bottom of the main vein from different directions even in horizontal conditions due to the Laplace pressure gradient and energy gradient. The simulation analysis demonstrates that the reason for directional transportation is the energy gradient of the droplets on the different levels of veins, including the thin veins, lateral veins, and main vein. Meanwhile, the experimental result of water collection also showed an outstanding directional transportation effect and excellent water collection efficiency. In addition, when the sample is tilted upside down, the droplet will flow back to the main vein along the lateral vein and then flow down the main vein, showing a good droplet pumping effect. Therefore, the directional and polydirectional transportation of droplets on the same sample is successfully realized, and the conversion between executing single and multiple tasks simultaneously can be realized only by upright and inverted samples. This work provided a new strategy for directional and polydirectional water manipulation, water collection, directional drainage, and microfluidic devices.
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Affiliation(s)
- Xiaojing Liang
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Deke Li
- School of Materials Engineering, Lanzhou Institute of Technology, Lanzhou 730050, People's Republic of China
| | - ShanPeng Li
- College of Engineering, Lishui University, Lishui 323000, People's Republic of China
| | - Chenggong Xu
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Zhiguang Guo
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China
- Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei University, Wuhan 430062, People's Republic of China
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