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Printing Polymeric Convex Lenses to Boost the Sensitivity of a Graphene-Based UV Sensor. Polymers (Basel) 2022; 14:polym14153204. [PMID: 35956718 PMCID: PMC9370982 DOI: 10.3390/polym14153204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 07/30/2022] [Accepted: 08/04/2022] [Indexed: 11/16/2022] Open
Abstract
Ultraviolet (UV) is widely used in daily life as well as in industrial manufacturing. In this study, a single-step postprocess to improve the sensitivity of a graphene-based UV sensor is studied. We leverage the advantage of electric-field-assisted on-demand printing, which is simply applicable for mounting functional polymers onto various structures. Here, the facile printing process creates optical plano-convex geometry by accelerating and colliding a highly viscous droplet on a micropatterned graphene channel. The printed transparent lens refracts UV rays. The concentrated UV photon energy from a wide field of view enhances the photodesorption of electron-hole pairs between the lens and the graphene sensor channel, which is coupled with a large change in resistance. As a result, the one-step post-treatment has about a 4× higher sensitivity compared to bare sensors without the lenses. We verify the applicability of printing and the boosting mechanism by variation of lens dimensions, a series of UV exposure tests, and optical simulation. Moreover, the method contributes to UV sensing in acute angle or low irradiation. In addition, the catalytic lens provides about a 9× higher recovery rate, where water molecules inside the PEI lens deliver fast reassembly of the electron-hole pairs. The presented method with an ultimately simple fabrication step is expected to be applied to academic research and prototyping, including optoelectronic sensors, energy devices, and advanced manufacturing processes.
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2
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Goralczyk A, Bhagwat S, Mayoussi F, Nekoonam N, Sachsenheimer K, Hou P, Kotz-Helmer F, Helmer D, Rapp BE. Application of Micro/Nanoporous Fluoropolymers with Reduced Bioadhesion in Digital Microfluidics. NANOMATERIALS 2022; 12:nano12132201. [PMID: 35808037 PMCID: PMC9268009 DOI: 10.3390/nano12132201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/24/2022] [Accepted: 06/25/2022] [Indexed: 02/01/2023]
Abstract
Digital microfluidics (DMF) is a versatile platform for conducting a variety of biological and chemical assays. The most commonly used set-up for the actuation of microliter droplets is electrowetting on dielectric (EWOD), where the liquid is moved by an electrostatic force on a dielectric layer. Superhydrophobic materials are promising materials for dielectric layers, especially since the minimum contact between droplet and surface is key for low adhesion of biomolecules, as it causes droplet pinning and cross contamination. However, superhydrophobic surfaces show limitations, such as full wetting transition between Cassie and Wenzel under applied voltage, expensive and complex fabrication and difficult integration into already existing devices. Here we present Fluoropor, a superhydrophobic fluorinated polymer foam with pores on the micro/nanoscale as a dielectric layer in DMF. Fluoropor shows stable wetting properties with no significant changes in the wetting behavior, or full wetting transition, until potentials of 400 V. Furthermore, Fluoropor shows low attachment of biomolecules to the surface upon droplet movement. Due to its simple fabrication process, its resistance to adhesion of biomolecules and the fact it is capable of being integrated and exchanged as thin films into commercial DMF devices, Fluoropor is a promising material for wide application in DMF.
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Affiliation(s)
- Andreas Goralczyk
- Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany; (A.G.); (S.B.); (F.M.); (N.N.); (K.S.); (P.H.); (F.K.-H.); (B.E.R.)
| | - Sagar Bhagwat
- Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany; (A.G.); (S.B.); (F.M.); (N.N.); (K.S.); (P.H.); (F.K.-H.); (B.E.R.)
| | - Fadoua Mayoussi
- Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany; (A.G.); (S.B.); (F.M.); (N.N.); (K.S.); (P.H.); (F.K.-H.); (B.E.R.)
| | - Niloofar Nekoonam
- Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany; (A.G.); (S.B.); (F.M.); (N.N.); (K.S.); (P.H.); (F.K.-H.); (B.E.R.)
| | - Kai Sachsenheimer
- Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany; (A.G.); (S.B.); (F.M.); (N.N.); (K.S.); (P.H.); (F.K.-H.); (B.E.R.)
| | - Peilong Hou
- Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany; (A.G.); (S.B.); (F.M.); (N.N.); (K.S.); (P.H.); (F.K.-H.); (B.E.R.)
| | - Frederik Kotz-Helmer
- Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany; (A.G.); (S.B.); (F.M.); (N.N.); (K.S.); (P.H.); (F.K.-H.); (B.E.R.)
- Freiburg Materials Research Center (FMF), University of Freiburg, 79104 Freiburg im Breisgau, Germany
| | - Dorothea Helmer
- Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany; (A.G.); (S.B.); (F.M.); (N.N.); (K.S.); (P.H.); (F.K.-H.); (B.E.R.)
- Freiburg Materials Research Center (FMF), University of Freiburg, 79104 Freiburg im Breisgau, Germany
- Freiburg Center of Interactive Materials and Bioinspired Technologies (FIT), University of Freiburg, 79110 Freiburg im Breisgau, Germany
- Correspondence:
| | - Bastian E. Rapp
- Laboratory of Process Technology, NeptunLab, Department of Microsystem Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany; (A.G.); (S.B.); (F.M.); (N.N.); (K.S.); (P.H.); (F.K.-H.); (B.E.R.)
- Freiburg Materials Research Center (FMF), University of Freiburg, 79104 Freiburg im Breisgau, Germany
- Freiburg Center of Interactive Materials and Bioinspired Technologies (FIT), University of Freiburg, 79110 Freiburg im Breisgau, Germany
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Yan W, Zhao C, Luo W, Zhang W, Li X, Liu D. Optically Guided Pyroelectric Manipulation of Water Droplet on a Superhydrophobic Surface. ACS APPLIED MATERIALS & INTERFACES 2021; 13:23181-23190. [PMID: 33945247 DOI: 10.1021/acsami.1c03407] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Controlled droplet manipulation by light has tremendous technological potential. We report here a method based on photothermally induced pyroelectric effects that enables manipulation and maneuvering of a water droplet on a superhydrophobic surface fabricated on lithium tantalite (LiTaO3). In particular, we demonstrate that the pyroelectric charge distribution has an essential role in this process. Evenly distributed charges promote a rapid hydrophobic to hydrophilic transition featuring a very large water contact angle (WCA) change of ∼76.5° in air. This process becomes fully reversible in silicone oil. In contrast, the localized charge distribution induced by guided laser illumination leads to very different and versatile functionalities, including droplet shape control and motion manipulation. The influence of a saline solution is also investigated and compared to the deionized water droplet. The focusing effect of the water droplet, a phenomenon that widely exists in nature, is particularly of interest. Simple tuning of the laser incident angle results in droplet deformation, jetting, splitting, and guided motion. Potential applications, such as droplet pinning and transfer, are presented. This approach offers a wide range of versatile functionalities and ready controllability, including contactless, electrodeless, and precise spatial and fast temporal control, with tremendous potential for applications requiring remote droplet control.
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Affiliation(s)
- Weishan Yan
- Institute of Novel Semiconductors, State Key Laboratory of Crystal Materials, Shandong University, 27 South Shanda Road, Jinan, Shandong 250100, P. R. China
| | - Chaopeng Zhao
- Institute of Novel Semiconductors, State Key Laboratory of Crystal Materials, Shandong University, 27 South Shanda Road, Jinan, Shandong 250100, P. R. China
| | - Wenyao Luo
- Institute of Novel Semiconductors, State Key Laboratory of Crystal Materials, Shandong University, 27 South Shanda Road, Jinan, Shandong 250100, P. R. China
| | - Wangyang Zhang
- Institute of Novel Semiconductors, State Key Laboratory of Crystal Materials, Shandong University, 27 South Shanda Road, Jinan, Shandong 250100, P. R. China
| | - Xi Li
- Key Laboratory of Experimental Teratology, Ministry of Education, Institute of Medical Genetics, School of Medicine, Shandong University, Jinan, Shandong 250012, P. R. China
| | - Duo Liu
- Institute of Novel Semiconductors, State Key Laboratory of Crystal Materials, Shandong University, 27 South Shanda Road, Jinan, Shandong 250100, P. R. China
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Chen PC, Chen LT, Yeh CS. Tunable microlens array fabricated by a silicone oil-induced swelled polydimethylsiloxane (PDMS) membrane bonded to a micro-milled microfluidic chip. OPTICS EXPRESS 2020; 28:29815-29828. [PMID: 33114872 DOI: 10.1364/oe.404637] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 09/11/2020] [Indexed: 06/11/2023]
Abstract
Microlens arrays (MLAs) nowadays are critical micro-optical components and they can be applied in many application fields, such as optical communication systems and flat panel display modules. This article describes a novel approach to the fabrication of tunable, highly reliable, and uniform polydimethylsiloxane (PDMS) MLAs. A polydimethylsiloxane (PDMS) membrane is bonded to a micro-milled poly(methyl methacrylate) (PMMA) microfluidic chip and exposed to silicone oil of a specific viscosity. Molecules in the oil insert themselves into the molecular structure of the PDMS membrane, causing it to swell and subsequently form dome-shaped MLAs. From our experiments, we derived the following conclusions. First, the homogeneous swelling of the PDMS resulted in MLAs with a high numerical aperture (0.5), high uniformity illumination (CV of the illumination intensity is between 2.5%∼5.1%), and high uniformity (CV of sag height of MLAs is less than 0.05). Second, the shorter molecular chains in low-viscosity oils diffused more readily into the PDMS membrane, which increased the effects on swelling, resulting in MLAs with higher sag height and higher numerical aperture. For example, the 5 cst silicone oil resulted in sag height of 191 µm with NA of 0.50, whereas the 100 cst silicone oil resulted in sag height of 86 µm with numerical aperture of 0.33. Finally, the integrated mixer module enabled the simultaneous tuning of the 7 × 7 MLAs simply by adjusting the injection flow rates of the constituent silicone oils.
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5
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Progress toward reversible electrowetting on geometrically patterned superhydrophobic surfaces. Curr Opin Colloid Interface Sci 2018. [DOI: 10.1016/j.cocis.2018.01.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Kavousanakis ME, Chamakos NT, Ellinas K, Tserepi A, Gogolides E, Papathanasiou AG. How to Achieve Reversible Electrowetting on Superhydrophobic Surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:4173-4179. [PMID: 29558803 DOI: 10.1021/acs.langmuir.7b04371] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Collapse (Cassie to Wenzel) wetting transitions impede the electrostatically induced reversible modification of wettability on superhydrophobic surfaces, unless a strong external actuation (e.g., substrate heating) is applied. Here we show that collapse transitions can be prevented (the droplet remains suspended on the solid roughness protrusions) when the electrostatic force, responsible for the wetting modification, is smoothly distributed along the droplet surface. The above argument is initially established theoretically and then verified experimentally.
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Affiliation(s)
- Michail E Kavousanakis
- School of Chemical Engineering , National Technical University of Athens , Athens 15780 , Greece
| | - Nikolaos T Chamakos
- School of Chemical Engineering , National Technical University of Athens , Athens 15780 , Greece
| | - Kosmas Ellinas
- Institute of Nanoscience and Nanotechnology, NCSR "Demokritos" , Aghia Paraskevi 15341 , Greece
| | - Angeliki Tserepi
- Institute of Nanoscience and Nanotechnology, NCSR "Demokritos" , Aghia Paraskevi 15341 , Greece
| | - Evangelos Gogolides
- Institute of Nanoscience and Nanotechnology, NCSR "Demokritos" , Aghia Paraskevi 15341 , Greece
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7
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Parihar V, Bandyopadhyay S, Das S, Dasgupta S. Anisotropic Electrowetting on Wrinkled Surfaces: Enhanced Wetting and Dependency on Initial Wetting State. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:1844-1854. [PMID: 29309153 DOI: 10.1021/acs.langmuir.7b03467] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Electrowetting on dielectric (EWOD) on unidirectional microstructured surfaces has recently evoked significant interest as they can modulate the effect of electrowetting, and can thus find applications in directional wetting in microfluidic systems. However, the dependency of such EW phenomenon on their initial state of wetting and anisotropy is far from being well understood. The current study addresses the initial wetting states and their implication on the anisotropic electrowetting using a wrinkled EWOD platform. Herein we demonstrate a facile stampless and maskless structure generation technique to fabricate wrinkles of varying topography. Further, we have demonstrated alteration in the interfacial wetting conditions by modulating the wrinkle topography, and its effect on the droplet behavior during electrowetting. The capillary wicking-assisted electrowetting on these wrinkled surfaces is in specific direction dictated by the ordered wrinkles and prompts enhanced spreading of the droplet. We also demonstrate that while the enhancement of unidirectional electrowetting is stronger in conformal wetting state surfaces, composite wetting state surfaces depict a reversal in anisotropy.
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Affiliation(s)
- Vartika Parihar
- Department of Chemical Engineering, ‡Advanced Technology Development Centre, and §School of Medical Science and Technology, Indian Institute of Technology Kharagpur , Kharagpur-721302, West Bengal, India
| | - Saumyadwip Bandyopadhyay
- Department of Chemical Engineering, ‡Advanced Technology Development Centre, and §School of Medical Science and Technology, Indian Institute of Technology Kharagpur , Kharagpur-721302, West Bengal, India
| | - Soumen Das
- Department of Chemical Engineering, ‡Advanced Technology Development Centre, and §School of Medical Science and Technology, Indian Institute of Technology Kharagpur , Kharagpur-721302, West Bengal, India
| | - Sunando Dasgupta
- Department of Chemical Engineering, ‡Advanced Technology Development Centre, and §School of Medical Science and Technology, Indian Institute of Technology Kharagpur , Kharagpur-721302, West Bengal, India
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8
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Ahmed R, Yetisen AK, Butt H. High Numerical Aperture Hexagonal Stacked Ring-Based Bidirectional Flexible Polymer Microlens Array. ACS NANO 2017; 11:3155-3165. [PMID: 28252935 DOI: 10.1021/acsnano.7b00211] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Flexible imprinted photonic nanostructures that are able to diffract/focus narrow-band light have potential applications in optical lenses, filters, tunable lasers, displays, and biosensing. Nanophotonic structures through holography and roll-to-roll printing may reduce fabrication complexities and expenses and enable mass production. Here, 3D photonic nanostructures of a stacked ring array were imprinted on acrylate polymer (AP) over poly(ethylene terephthalate) (PET) substrate through holography and lift-off processes to create a microlens array (MLA). The surface structure of the array consisted of circular nonostepped pyramids, and repeated patterns were in hexagonal arrangements. Stacked-ring-based MLA (SMLA) on a flexible AP-PET substrate showed efficient bidirectional light focusing and maximum numerical aperture (NA = 0.60) with a reasonable filling factor. The nanostructures produced a well-ordered hexagonally focused diffraction pattern in the far field, and power intensities were measured through angle-resolved experiments. The variation of nanostep dimensions (width and height) and the number of steps resulted in different photonic bandgaps, and the arrays produced distance-dependent narrow-band light focusing. The validation of the SMLA was demonstrated through the text, image, and hologram projection experiments. It is anticipated that imprinted bidirectional SMLA over flexible substrates may find applications in optical systems, displays, and portable sensors.
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Affiliation(s)
- Rajib Ahmed
- Microengineering and Nanotechnology Laboratory, School of Engineering, University of Birmingham , Birmingham B15 2TT, United Kingdom
| | - Ali K Yetisen
- Harvard Medical School and Division of Biomedical Engineering, Brigham and Women's Hospital , 65 Lansdowne Street, Cambridge, Massachusetts 02139, United States
- Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology , 65 Landsdowne Street, Cambridge, Massachusetts 02139, United States
| | - Haider Butt
- Microengineering and Nanotechnology Laboratory, School of Engineering, University of Birmingham , Birmingham B15 2TT, United Kingdom
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9
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Abstract
This review systematically summarizes the recent developments of superoleophobic surfaces, focusing on their design, fabrication, characteristics, functions, and important applications.
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Affiliation(s)
- Jiale Yong
- State Key Laboratory for Manufacturing System Engineering and Shaanxi Key Laboratory of Photonics Technology for Information
- School of Electronics & Information Engineering
- Xi’an Jiaotong University
- Xi’an
- P. R. China
| | - Feng Chen
- State Key Laboratory for Manufacturing System Engineering and Shaanxi Key Laboratory of Photonics Technology for Information
- School of Electronics & Information Engineering
- Xi’an Jiaotong University
- Xi’an
- P. R. China
| | - Qing Yang
- School of Mechanical Engineering
- Xi’an Jiaotong University
- Xi’an
- P. R. China
| | - Jinglan Huo
- State Key Laboratory for Manufacturing System Engineering and Shaanxi Key Laboratory of Photonics Technology for Information
- School of Electronics & Information Engineering
- Xi’an Jiaotong University
- Xi’an
- P. R. China
| | - Xun Hou
- State Key Laboratory for Manufacturing System Engineering and Shaanxi Key Laboratory of Photonics Technology for Information
- School of Electronics & Information Engineering
- Xi’an Jiaotong University
- Xi’an
- P. R. China
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10
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Tian H, Shao J, Hu H, Wang L, Ding Y. Role of space charges inside a dielectric polymer in the electrohydrodynamic structure formation on a prepatterned polymer (ESF-PP). RSC Adv 2016. [DOI: 10.1039/c6ra14479a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Mushroom-shaped structures with a high aspect ratio are fabricated based on the action of space charges inside the dielectric polymer.
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Affiliation(s)
- Hongmiao Tian
- Micro- and Nano-technology Research Center
- State Key Laboratory for Manufacturing Systems Engineering
- Xi'an Jiaotong University
- Xi'an
- P. R. China
| | - Jinyou Shao
- Micro- and Nano-technology Research Center
- State Key Laboratory for Manufacturing Systems Engineering
- Xi'an Jiaotong University
- Xi'an
- P. R. China
| | - Hong Hu
- Micro- and Nano-technology Research Center
- State Key Laboratory for Manufacturing Systems Engineering
- Xi'an Jiaotong University
- Xi'an
- P. R. China
| | - Li Wang
- Micro- and Nano-technology Research Center
- State Key Laboratory for Manufacturing Systems Engineering
- Xi'an Jiaotong University
- Xi'an
- P. R. China
| | - Yucheng Ding
- Micro- and Nano-technology Research Center
- State Key Laboratory for Manufacturing Systems Engineering
- Xi'an Jiaotong University
- Xi'an
- P. R. China
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11
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Kong X, Zhang J, Liao X, Huang X, Shi B. A facile synthesis of a highly stable superhydrophobic nanofibrous film for effective oil/water separation. RSC Adv 2016. [DOI: 10.1039/c6ra17832d] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
An oil/water separation film with excellent durability and stable recyclability is highly desired for the treatment of oil containing effluents, like industrial oily wastewater.
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Affiliation(s)
- Xian Kong
- Department of Biomass Chemistry and Engineering
- Sichuan University
- Chengdu 610065
- China
- National Engineering Laboratory for Clean Technology of Leather Manufacture
| | - Junming Zhang
- National Engineering Laboratory for Clean Technology of Leather Manufacture
- Sichuan University
- Chengdu 610065
- China
| | - Xuepin Liao
- National Engineering Laboratory for Clean Technology of Leather Manufacture
- Sichuan University
- Chengdu 610065
- China
| | - Xin Huang
- Department of Biomass Chemistry and Engineering
- Sichuan University
- Chengdu 610065
- China
- National Engineering Laboratory for Clean Technology of Leather Manufacture
| | - Bi Shi
- Department of Biomass Chemistry and Engineering
- Sichuan University
- Chengdu 610065
- China
- National Engineering Laboratory for Clean Technology of Leather Manufacture
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Liu Y, Liang YE, Sheng YJ, Tsao HK. Ultralow voltage irreversible electrowetting dynamics of an aqueous drop on a stainless steel surface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:3840-3846. [PMID: 25730308 DOI: 10.1021/acs.langmuir.5b00411] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The electrowetting dynamics of a water drop on a stainless steel surface in air is investigated under ultralow voltages. The spreading behavior can be classified into three regimes. The drop expands slowly in regime I, but the spreading accelerates quite rapidly in regime II. The spreading becomes insignificant in regime III. The experimental results are compared to the equilibrium shapes acquired by Surface Evolver simulations. The good agreement between them indicates that the slow electrowetting dynamics can be considered to be a quasi-equilibrium process. The influences of the electric field and drop size on the spreading dynamics are examined. The variation of both the contact angle and base diameter with time in regimes II and III can be well described by the exponential change with a characteristic time, which grows with the drop volume but is inversely proportional to the electric field. A simple model based on the electromechnical mechanism is proposed to explain the spreading dynamics. The exponential change is attributed to ion migration from the bulk of the drop to the contact line. The experimental results agree well with the prediction of our simple theory.
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Affiliation(s)
- Yanna Liu
- †Faculty of Chemical Engineering, Kunming University of Science and Technology, Kunming 650500, China
| | - Yu-En Liang
- ∥Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan 106, R.O.C
| | - Yu-Jane Sheng
- ∥Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan 106, R.O.C
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Sahoo BN, Kandasubramanian B. Recent progress in fabrication and characterisation of hierarchical biomimetic superhydrophobic structures. RSC Adv 2014. [DOI: 10.1039/c4ra00506f] [Citation(s) in RCA: 143] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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Lapierre F, Coffinier Y, Boukherroub R, Thomy V. Electro-(de)wetting on superhydrophobic surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:13346-13351. [PMID: 24088024 DOI: 10.1021/la4026848] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Usually, electrowetting on superhydrophobic surfaces (EWOSS) is generated by application of an alternating current signal and often leads to droplet impalement into the structuration. To avoid this phenomenon, superhydrophobic surfaces must show robustness to high pressure. Otherwise, an external energy has to be applied to dewet the droplet from the structuration. We present, in this article, an original approach to actuate liquid droplets via a modulated EWOSS signal (MEWOSS). This technique allows the dewetting of the droplet due to periodic vibrations induced by the electrowetting actuation. In that case, it is possible to investigate a larger range of superhydrophobic surfaces under EWOSS without droplet impalement. Three different superhydrophobic surfaces, showing different degrees of impalement under EWOSS, are investigated and compared using this MEWOSS technique.
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Affiliation(s)
- Florian Lapierre
- Institute of Electronics, Microelectronics and Nanotechnology (IEMN), UMR CNRS 8520, University Lille1 , F-59652 Villeneuve d'Ascq, France
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15
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Kim JH, Kim YH, Jeong HS, Srinivasarao M, Hudson SD, Jung HT. Thermally responsive microlens arrays fabricated with the use of defect arrays in a smectic liquid crystal. RSC Adv 2012. [DOI: 10.1039/c2ra20561k] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Zhu X, Zhang Z, Wang K, Yang J, Xu X, Men X, Zhou X. A facile route to mechanically durable responsive surfaces with reversible wettability switching. NEW J CHEM 2012. [DOI: 10.1039/c2nj00014h] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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