1
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Donati M, Regulagadda K, Lam CWE, Milionis A, Sharma CS, Poulikakos D. Metal Surface Engineering for Extreme Sustenance of Jumping Droplet Condensation. Langmuir 2024; 40:1257-1265. [PMID: 38156900 PMCID: PMC10795172 DOI: 10.1021/acs.langmuir.3c02713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 12/11/2023] [Accepted: 12/12/2023] [Indexed: 01/03/2024]
Abstract
Water vapor condensation on metallic surfaces is critical to a broad range of applications, ranging from power generation to the chemical and pharmaceutical industries. Enhancing simultaneously the heat transfer efficiency, scalability, and durability of a condenser surface remains a persistent challenge. Coalescence-induced condensing droplet jumping is a capillarity-driven mechanism of self-ejection of microscopic condensate droplets from a surface. This mechanism is highly desired due to the fact that it continuously frees up the surface for new condensate to form directly on the surface, enhancing heat transfer without requiring the presence of the gravitational field. However, this condensate ejection mechanism typically requires the fabrication of surface nanotextures coated by an ultrathin (<10 nm) conformal hydrophobic coating (hydrophobic self-assembled monolayers such as silanes), which results in poor durability. Here, we present a scalable approach for the fabrication of a hierarchically structured superhydrophobic surface on aluminum substrates, which is able to withstand adverse conditions characterized by condensation of superheated steam shear flow at pressure and temperature up to ≈1.42 bar and ≈111 °C, respectively, and velocities in the range ≈3-9 m/s. The synergetic function of micro- and nanotextures, combined with a chemically grafted, robust ultrathin (≈4.0 nm) poly-1H,1H,2H,2H-perfluorodecyl acrylate (pPFDA) coating, which is 1 order of magnitude thinner than the current state of the art, allows the sustenance of long-term coalescence-induced condensate jumping drop condensation for at least 72 h. This yields unprecedented, up to an order of magnitude higher heat transfer coefficients compared to filmwise condensation under the same conditions and significantly outperforms the current state of the art in terms of both durability and performance establishing a new milestone.
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Affiliation(s)
- Matteo Donati
- Laboratory
of Thermodynamics in Emerging Technologies, Department of Mechanical
and Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland
| | - Kartik Regulagadda
- Laboratory
of Thermodynamics in Emerging Technologies, Department of Mechanical
and Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland
| | - Cheuk Wing Edmond Lam
- Laboratory
of Thermodynamics in Emerging Technologies, Department of Mechanical
and Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland
| | - Athanasios Milionis
- Laboratory
of Thermodynamics in Emerging Technologies, Department of Mechanical
and Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland
| | - Chander Shekhar Sharma
- Thermofluidics
Research Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Ropar, Rupnagar 140001, Punjab, India
| | - Dimos Poulikakos
- Laboratory
of Thermodynamics in Emerging Technologies, Department of Mechanical
and Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland
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2
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Li S, Lam CWE, Donati M, Regulagadda K, Yavuz E, Pfeiffer T, Sarkiris P, Gogolides E, Milionis A, Poulikakos D, Butt HJ, Kappl M. Durable, Ultrathin, and Antifouling Polymer Brush Coating for Efficient Condensation Heat Transfer. ACS Appl Mater Interfaces 2024; 16:1941-1949. [PMID: 38115194 PMCID: PMC10788830 DOI: 10.1021/acsami.3c17293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 11/28/2023] [Accepted: 11/28/2023] [Indexed: 12/21/2023]
Abstract
Heat exchangers are made of metals because of their high heat conductivity and mechanical stability. Metal surfaces are inherently hydrophilic, leading to inefficient filmwise condensation. It is still a challenge to coat these metal surfaces with a durable, robust, and thin hydrophobic layer, which is required for efficient dropwise condensation. Here, we report the nonstructured and ultrathin (∼6 nm) polydimethylsiloxane (PDMS) brushes on copper that sustain high-performing dropwise condensation in high supersaturation. Due to the flexible hydrophobic siloxane polymer chains, the coating has low resistance to drop sliding and excellent chemical stability. The PDMS brushes can sustain dropwise condensation for up to ∼8 h during exposure to 111 °C saturated steam flowing at 3 m·s-1, with a 5-7 times higher heat transfer coefficient compared to filmwise condensation. The surface is self-cleaning and can reduce the level of bacterial attachment by 99%. This low-cost, facile, fluorine-free, and scalable method is suitable for a great variety of heat transfer applications.
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Affiliation(s)
- Shuai Li
- Max
Planck Institute for Polymer Research, 55128 Mainz, Germany
| | - Cheuk Wing Edmond Lam
- Department
of Mechanical and Process Engineering, Laboratory of Thermodynamics
in Emerging Technologies, ETH Zurich, 8092 Zurich, Switzerland
| | - Matteo Donati
- Department
of Mechanical and Process Engineering, Laboratory of Thermodynamics
in Emerging Technologies, ETH Zurich, 8092 Zurich, Switzerland
| | - Kartik Regulagadda
- Department
of Mechanical and Process Engineering, Laboratory of Thermodynamics
in Emerging Technologies, ETH Zurich, 8092 Zurich, Switzerland
| | - Emre Yavuz
- Max
Planck Institute for Polymer Research, 55128 Mainz, Germany
| | - Till Pfeiffer
- Institute
for Technical Thermodynamics, Technical
University of Darmstadt, 64287 Darmstadt, Germany
| | - Panagiotis Sarkiris
- Institute
of Nanoscience and Nanotechnology, NCSR
“Demokritos”, 15341Agia Paraskevi, Attiki, Greece
| | - Evangelos Gogolides
- Institute
of Nanoscience and Nanotechnology, NCSR
“Demokritos”, 15341Agia Paraskevi, Attiki, Greece
| | - Athanasios Milionis
- Department
of Mechanical and Process Engineering, Laboratory of Thermodynamics
in Emerging Technologies, ETH Zurich, 8092 Zurich, Switzerland
| | - Dimos Poulikakos
- Department
of Mechanical and Process Engineering, Laboratory of Thermodynamics
in Emerging Technologies, ETH Zurich, 8092 Zurich, Switzerland
| | | | - Michael Kappl
- Max
Planck Institute for Polymer Research, 55128 Mainz, Germany
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3
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Xesfyngi Y, Georgoutsou-Spyridonos M, Tripathy A, Milionis A, Poulikakos D, Mastellos DC, Tserepi A. A High-Performance Antibacterial Nanostructured ZnO Microfluidic Device for Controlled Bacterial Lysis and DNA Release. Antibiotics (Basel) 2023; 12:1276. [PMID: 37627695 PMCID: PMC10451374 DOI: 10.3390/antibiotics12081276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 07/27/2023] [Accepted: 08/01/2023] [Indexed: 08/27/2023] Open
Abstract
In this work, the antibacterial properties of nanostructured zinc oxide (ZnO) surfaces are explored by incorporating them as walls in a simple-to-fabricate microchannel device. Bacterial cell lysis is demonstrated and quantified in such a device, which functions due to the action of its nanostructured ZnO surfaces in contact with the working fluid. To shed light on the mechanism responsible for lysis, E. coli bacteria were incubated in zinc and nanostructured ZnO substrates, as well as the here-investigated ZnO-based microfluidic devices. The unprecedented killing efficiency of E. coli in nanostructured ZnO microchannels, effective after a 15 min incubation, paves the way for the implementation of such microfluidic chips in the disinfection of bacteria-containing solutions. In addition, the DNA release was confirmed by off-chip PCR and UV absorption measurements. The results indicate that the present nanostructured ZnO-based microfluidic chip can, under light, achieve partial inactivation of the released bacterial DNA via reactive oxygen species-mediated oxidative damage. The present device concept can find broader applications in cases where the presence of DNA in a sample is not desirable. Furthermore, the present microchannel device enables, in the dark, efficient release of bacterial DNA for downstream genomic DNA analysis. The demonstrated potential of this antibacterial device for tailored dual functionality in light/dark conditions is the main novel contribution of the present work.
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Affiliation(s)
- Yvonni Xesfyngi
- Institute of Nanoscience and Nanotechnology, National Center for Scientific Research (NCSR) “Demokritos”, Patr. Gregoriou E’ and 27 Neapoleos Str., 15341 Aghia Paraskevi, Greece; (Y.X.); (M.G.-S.)
| | - Maria Georgoutsou-Spyridonos
- Institute of Nanoscience and Nanotechnology, National Center for Scientific Research (NCSR) “Demokritos”, Patr. Gregoriou E’ and 27 Neapoleos Str., 15341 Aghia Paraskevi, Greece; (Y.X.); (M.G.-S.)
| | - Abinash Tripathy
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland; (A.T.); (A.M.); (D.P.)
| | - Athanasios Milionis
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland; (A.T.); (A.M.); (D.P.)
| | - Dimos Poulikakos
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland; (A.T.); (A.M.); (D.P.)
| | - Dimitrios C. Mastellos
- Institute of Nuclear & Radiological Sciences and Technology, Energy & Safety, National Center for Scientific Research (NCSR) “Demokritos”, Patr. Gregoriou E’ and 27 Neapoleos Str., 15341 Aghia Paraskevi, Greece;
| | - Angeliki Tserepi
- Institute of Nanoscience and Nanotechnology, National Center for Scientific Research (NCSR) “Demokritos”, Patr. Gregoriou E’ and 27 Neapoleos Str., 15341 Aghia Paraskevi, Greece; (Y.X.); (M.G.-S.)
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4
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Rieber J, Meier-Bürgisser G, Miescher I, Weber FE, Wolint P, Yao Y, Ongini E, Milionis A, Snedeker JG, Calcagni M, Buschmann J. Bioactive and Elastic Emulsion Electrospun DegraPol Tubes Delivering IGF-1 for Tendon Rupture Repair. Int J Mol Sci 2023; 24:10272. [PMID: 37373418 DOI: 10.3390/ijms241210272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 06/14/2023] [Accepted: 06/14/2023] [Indexed: 06/29/2023] Open
Abstract
Tendon injuries can result in two major drawbacks. Adhesions to the surrounding tissue may limit the range of motion, while fibrovascular scar formation can lead to poor biomechanical outcomes. Prosthetic devices may help to mitigate those problems. Emulsion electrospinning was used to develop a novel three-layer tube based on the polymer DegraPol (DP), with incorporated insulin-like growth factor-1 (IGF-1) in the middle layer. Scanning electron microscopy was utilized to assess the fiber diameter in IGF-1 containing pure DP meshes. Further characterization was performed with Fourier Transformed Infrared Spectroscopy, Differential Scanning Calorimetry, and water contact angle, as well as through the assessment of mechanical properties and release kinetics from ELISA, and the bioactivity of IGF-1 by qPCR of collagen I, ki67, and tenomodulin in rabbit Achilles tenocytes. The IGF-1-containing tubes exhibited a sustained release of the growth factor up to 4 days and showed bioactivity by significantly upregulated ki67 and tenomodulin gene expression. Moreover, they proved to be mechanically superior to pure DP tubes (significantly higher fracture strain, failure stress, and elastic modulus). The novel three-layer tubes intended to be applied over conventionally sutured tendons after a rupture may help accelerate the healing process. The release of IGF-1 stimulates proliferation and matrix synthesis of cells at the repair site. In addition, adhesion formation to surrounding tissue can be reduced due to the physical barrier.
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Affiliation(s)
- Julia Rieber
- Division of Plastic Surgery and Hand Surgery, University Hospital Zurich, Sternwartstrasse 14, 8091 Zurich, Switzerland
| | - Gabriella Meier-Bürgisser
- Division of Plastic Surgery and Hand Surgery, University Hospital Zurich, Sternwartstrasse 14, 8091 Zurich, Switzerland
| | - Iris Miescher
- Division of Plastic Surgery and Hand Surgery, University Hospital Zurich, Sternwartstrasse 14, 8091 Zurich, Switzerland
| | - Franz E Weber
- Oral Biotechnology & Bioengineering, Center for Dental Medicine, Cranio-Maxillofacial and Oral Surgery, University of Zurich, 8032 Zurich, Switzerland
| | - Petra Wolint
- Division of Plastic Surgery and Hand Surgery, University Hospital Zurich, Sternwartstrasse 14, 8091 Zurich, Switzerland
| | - Yang Yao
- Department of Health Sciences & Technology & Department of Materials, Schmelzbergstrasse 9, LFO, 8092 Zurich, Switzerland
| | - Esteban Ongini
- Orthopaedic Biomechanics, University Clinic Balgrist, Forchstrasse 340, 8008 Zurich, Switzerland
| | - Athanasios Milionis
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Jess G Snedeker
- Orthopaedic Biomechanics, University Clinic Balgrist, Forchstrasse 340, 8008 Zurich, Switzerland
| | - Maurizio Calcagni
- Division of Plastic Surgery and Hand Surgery, University Hospital Zurich, Sternwartstrasse 14, 8091 Zurich, Switzerland
| | - Johanna Buschmann
- Division of Plastic Surgery and Hand Surgery, University Hospital Zurich, Sternwartstrasse 14, 8091 Zurich, Switzerland
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5
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Stendardo L, Milionis A, Kokkoris G, Stamatopoulos C, Sharma CS, Kumar R, Donati M, Poulikakos D. Out-of-Plane Biphilic Surface Structuring for Enhanced Capillary-Driven Dropwise Condensation. Langmuir 2023; 39:1585-1592. [PMID: 36645348 PMCID: PMC9893811 DOI: 10.1021/acs.langmuir.2c03029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 12/30/2022] [Indexed: 06/17/2023]
Abstract
Rapid and sustained condensate droplet departure from a surface is key toward achieving high heat-transfer rates in condensation, a physical process critical to a broad range of industrial and societal applications. Despite the progress in enhancing condensation heat transfer through inducing its dropwise mode with hydrophobic materials, sophisticated surface engineering methods that can lead to further enhancement of heat transfer are still highly desirable. Here, by employing a three-dimensional, multiphase computational approach, we present an effective out-of-plane biphilic surface topography, which reveals an unexplored capillarity-driven departure mechanism of condensate droplets. This texture consists of biphilic diverging microcavities wherein a matrix of small hydrophilic spots is placed at their bottom, that is, among the pyramid-shaped, superhydrophobic microtextures forming the cavities. We show that an optimal combination of the hydrophilic spots and the angles of the pyramidal structures can achieve high deformational stretching of the droplets, eventually realizing an impressive "slingshot-like" droplet ejection process from the texture. Such a droplet departure mechanism has the potential to reduce the droplet ejection volume and thus enhance the overall condensation efficiency, compared to coalescence-initiated droplet jumping from other state-of-the-art surfaces. Simulations have shown that optimal pyramid-shaped biphilic microstructures can provoke droplet self-ejection at low volumes, up to 56% lower than superhydrophobic straight pillars, revealing a promising new surface microtexture design strategy toward enhancing the condensation heat-transfer efficiency and water harvesting capabilities.
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Affiliation(s)
- Luca Stendardo
- Laboratory
of Thermodynamics in Emerging Technologies (LTNT), ETH Zurich, Sonneggstrasse
3, Zurich 8092, Switzerland
| | - Athanasios Milionis
- Laboratory
of Thermodynamics in Emerging Technologies (LTNT), ETH Zurich, Sonneggstrasse
3, Zurich 8092, Switzerland
| | - George Kokkoris
- Institute
of Nanoscience and Nanotechnology, NCSR
Demokritos, Agia Paraskevi 15341, Greece
- School
of Chemical Engineering, National Technical
University of Athens, Heroon Polytechniou 9, Zografou, Athens 15780, Greece
| | - Christos Stamatopoulos
- Laboratory
of Thermodynamics in Emerging Technologies (LTNT), ETH Zurich, Sonneggstrasse
3, Zurich 8092, Switzerland
| | - Chander Shekhar Sharma
- Thermofluidics
Research Lab, Department of Mechanical Engineering, Indian Institute of Technology Ropar, Rupnagar, Punjab 140001 India
| | - Raushan Kumar
- Thermofluidics
Research Lab, Department of Mechanical Engineering, Indian Institute of Technology Ropar, Rupnagar, Punjab 140001 India
| | - Matteo Donati
- Laboratory
of Thermodynamics in Emerging Technologies (LTNT), ETH Zurich, Sonneggstrasse
3, Zurich 8092, Switzerland
| | - Dimos Poulikakos
- Laboratory
of Thermodynamics in Emerging Technologies (LTNT), ETH Zurich, Sonneggstrasse
3, Zurich 8092, Switzerland
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6
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Tripathy A, Regulagadda K, Lam CWE, Donati MA, Milionis A, Sharma CS, Mitridis E, Schutzius TM, Poulikakos D. Ultrathin Durable Organic Hydrophobic Coatings Enhancing Dropwise Condensation Heat Transfer. Langmuir 2022; 38:11296-11303. [PMID: 36037308 PMCID: PMC9494938 DOI: 10.1021/acs.langmuir.2c01477] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 08/17/2022] [Indexed: 06/15/2023]
Abstract
Organic hydrophobic layers targeting sustained dropwise condensation are highly desirable but suffer from poor chemical and mechanical stability, combined with low thermal conductivity. The requirement of such layers to remain ultrathin to minimize their inherent thermal resistance competes against durability considerations. Here, we investigate the long-term durability and enhanced heat-transfer performance of perfluorodecanethiol (PFDT) coatings compared to alternative organic coatings, namely, perfluorodecyltriethoxysilane (PFDTS) and perfluorodecyl acrylate (PFDA), the latter fabricated with initiated chemical vapor deposition (iCVD), in condensation heat transfer and under the challenging operating conditions of intense flow (up to 9 m s-1) of superheated steam (111 °C) at high pressures (1.42 bar). We find that the thiol coating clearly outperforms the silane coating in terms of both heat transfer and durability. In addition, despite being only a monolayer, it clearly also outperforms the iCVD-fabricated PFDA coating in terms of durability. Remarkably, the thiol layer exhibited dropwise condensation for at least 63 h (>2× times more than the PFDA coating, which survived for 30 h), without any visible deterioration, showcasing its hydrolytic stability. The cost of thiol functionalization per area was also the lowest as compared to all of the other surface hydrophobic treatments used in this study, thus making it the most efficient option for practical applications on copper substrates.
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Affiliation(s)
- Abinash Tripathy
- Laboratory
of Thermodynamics in Emerging Technologies, Department of Mechanical
and Process Engineering, ETH Zurich, Sonneggstrasse 3, CH-8092 Zurich, Switzerland
| | - Kartik Regulagadda
- Laboratory
of Thermodynamics in Emerging Technologies, Department of Mechanical
and Process Engineering, ETH Zurich, Sonneggstrasse 3, CH-8092 Zurich, Switzerland
| | - Cheuk Wing Edmond Lam
- Laboratory
of Thermodynamics in Emerging Technologies, Department of Mechanical
and Process Engineering, ETH Zurich, Sonneggstrasse 3, CH-8092 Zurich, Switzerland
| | - Matteo A. Donati
- Laboratory
of Thermodynamics in Emerging Technologies, Department of Mechanical
and Process Engineering, ETH Zurich, Sonneggstrasse 3, CH-8092 Zurich, Switzerland
| | - Athanasios Milionis
- Laboratory
of Thermodynamics in Emerging Technologies, Department of Mechanical
and Process Engineering, ETH Zurich, Sonneggstrasse 3, CH-8092 Zurich, Switzerland
| | - Chander Shekhar Sharma
- Thermofluidics
Research Lab, Department of Mechanical Engineering, Indian Institute of Technology Ropar, Rupnagar, Punjab 140 001, India
| | - Efstratios Mitridis
- Laboratory
of Thermodynamics in Emerging Technologies, Department of Mechanical
and Process Engineering, ETH Zurich, Sonneggstrasse 3, CH-8092 Zurich, Switzerland
| | - Thomas M. Schutzius
- Laboratory
of Thermodynamics in Emerging Technologies, Department of Mechanical
and Process Engineering, ETH Zurich, Sonneggstrasse 3, CH-8092 Zurich, Switzerland
| | - Dimos Poulikakos
- Laboratory
of Thermodynamics in Emerging Technologies, Department of Mechanical
and Process Engineering, ETH Zurich, Sonneggstrasse 3, CH-8092 Zurich, Switzerland
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7
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Lohmann SC, Tripathy A, Milionis A, Keller A, Poulikakos D. Effect of Flexibility and Size of Nanofabricated Topographies on the Mechanobactericidal Efficacy of Polymeric Surfaces. ACS Appl Bio Mater 2022; 5:1564-1575. [PMID: 35176858 DOI: 10.1021/acsabm.1c01318] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Driven by the growing threat of antimicrobial resistance, the design of intrinsically bactericidal surfaces has been gaining significant attention. Proposed surface topography designs are often inspired by naturally occurring nanopatterns on insect wings that mechanically damage bacteria via membrane deformation. The stability of and the absence of chemicals in such surfaces support their facile and sustainable employment in avoiding surface-born pathogen transmission. Recently, the deflection of controllably nanofabricated pillar arrays has been shown to strongly affect bactericidal activity, with the limits of mechanical effectiveness of such structures remaining largely unexplored. Here, we examine the limits of softer, commonly used polymeric materials and investigate the interplay between pillar nanostructure sizing and flexibility for effective antibacterial functionality. A facile, scalable, UV nanoimprint lithography method was used to fabricate nanopillar array topographies of variable sizes and flexibilities. It was found that bacterial death on nanopillars in the range of diameters ≤100 nm and Young's moduli ≥1.3 GPa is increased by 3.5- to 5.6-fold, while thicker or softer pillars did not reduce bacterial viability. To further support our findings, we performed a finite element analysis of pillar deformation. It revealed that differences in the amount of stress exerted on bacterial membranes, generated from the stored elastic energy in flexible pillars, contribute to the observed bactericidal performance.
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Affiliation(s)
- Sophie C Lohmann
- Laboratory of Thermodynamics in Emerging Technologies, ETH Zurich, Zurich 8092, Switzerland
| | - Abinash Tripathy
- Laboratory of Thermodynamics in Emerging Technologies, ETH Zurich, Zurich 8092, Switzerland
| | - Athanasios Milionis
- Laboratory of Thermodynamics in Emerging Technologies, ETH Zurich, Zurich 8092, Switzerland
| | - Anja Keller
- Institute of Food, Nutrition and Health, ETH Zurich, Zurich 8092, Switzerland
| | - Dimos Poulikakos
- Laboratory of Thermodynamics in Emerging Technologies, ETH Zurich, Zurich 8092, Switzerland
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8
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Tripathy A, Lam CWE, Davila D, Donati M, Milionis A, Sharma CS, Poulikakos D. Ultrathin Lubricant-Infused Vertical Graphene Nanoscaffolds for High-Performance Dropwise Condensation. ACS Nano 2021; 15:14305-14315. [PMID: 34399576 DOI: 10.1021/acsnano.1c02932] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Lubricant-infused surfaces (LIS) are highly efficient in repelling water and constitute a very promising family of materials for condensation processes occurring in a broad range of energy applications. However, the performance of LIS in such processes is limited by the inherent thermal resistance imposed by the thickness of the lubricant and supporting surface structure, as well as by the gradual depletion of the lubricant over time. Here, we present an ultrathin (∼70 nm) and conductive LIS architecture, obtained by infusing lubricant into a vertically grown graphene nanoscaffold on copper. The ultrathin nature of the scaffold, combined with the high in-plane thermal conductivity of graphene, drastically minimize earlier limitations, effectively doubling the heat transfer performance compared to a state-of-the-art CuO LIS surface. We show that the effect of the thermal resistance to the heat transfer performance of a LIS surface, although often overlooked, can be so detrimental that a simple nanostructured CuO surface can outperform a CuO LIS surface, despite filmwise condensation on the former. The present vertical graphene LIS is also found to be resistant to lubricant depletion, maintaining stable dropwise condensation for at least 24 h with no significant change of advancing contact angle and contact angle hysteresis. The lubricant consumed by the vertical graphene LIS is 52.6% less than that of the existing state-of-the-art CuO LIS, also making the fabrication process more economical.
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Affiliation(s)
- Abinash Tripathy
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland
| | - Cheuk Wing Edmond Lam
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland
| | - Diana Davila
- IBM Research, Saeumerstrasse 4, 8803 Rueschlikon, Switzerland
| | - Matteo Donati
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland
| | - Athanasios Milionis
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland
| | - Chander Shekhar Sharma
- Thermofluidics Research Lab, Department of Mechanical Engineering, Indian Institute of Technology Ropar, Rupnagar, Punjab 140001, India
| | - Dimos Poulikakos
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich, Sonneggstrasse 3, 8092 Zurich, Switzerland
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9
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Haechler I, Park H, Schnoering G, Gulich T, Rohner M, Tripathy A, Milionis A, Schutzius TM, Poulikakos D. Exploiting radiative cooling for uninterrupted 24-hour water harvesting from the atmosphere. Sci Adv 2021; 7:7/26/eabf3978. [PMID: 34162540 PMCID: PMC8221617 DOI: 10.1126/sciadv.abf3978] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 05/10/2021] [Indexed: 05/12/2023]
Abstract
Atmospheric water vapor is ubiquitous and represents a promising alternative to address global clean water scarcity. Sustainably harvesting this resource requires energy neutrality, continuous production, and facility of use. However, fully passive and uninterrupted 24-hour atmospheric water harvesting remains a challenge. Here, we demonstrate a rationally designed system that synergistically combines radiative shielding and cooling-dissipating the latent heat of condensation radiatively to outer space-with a fully passive superhydrophobic condensate harvester, working with a coalescence-induced water removal mechanism. A rationally designed shield, accounting for the atmospheric radiative heat, facilitates daytime atmospheric water harvesting under solar irradiation at realistic levels of relative humidity. The remarkable cooling power enhancement enables dew mass fluxes up to 50 g m-2 hour-1, close to the ultimate capabilities of such systems. Our results demonstrate that the yield of related technologies can be at least doubled, while cooling and collection remain passive, thereby substantially advancing the state of the art.
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Affiliation(s)
- Iwan Haechler
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich, Sonneggstrasse 3, CH-8092 Zurich, Switzerland
| | - Hyunchul Park
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich, Sonneggstrasse 3, CH-8092 Zurich, Switzerland
| | - Gabriel Schnoering
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich, Sonneggstrasse 3, CH-8092 Zurich, Switzerland
| | - Tobias Gulich
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich, Sonneggstrasse 3, CH-8092 Zurich, Switzerland
| | - Mathieu Rohner
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich, Sonneggstrasse 3, CH-8092 Zurich, Switzerland
| | - Abinash Tripathy
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich, Sonneggstrasse 3, CH-8092 Zurich, Switzerland
| | - Athanasios Milionis
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich, Sonneggstrasse 3, CH-8092 Zurich, Switzerland
| | - Thomas M Schutzius
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich, Sonneggstrasse 3, CH-8092 Zurich, Switzerland.
| | - Dimos Poulikakos
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich, Sonneggstrasse 3, CH-8092 Zurich, Switzerland.
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Stamatopoulos C, Milionis A, Ackerl N, Donati M, Leudet de la Vallée P, Rudolf von Rohr P, Poulikakos D. Droplet Self-Propulsion on Superhydrophobic Microtracks. ACS Nano 2020; 14:12895-12904. [PMID: 32806052 DOI: 10.1021/acsnano.0c03849] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Liquid transport (continuous or segmented) in microfluidic platforms typically requires pumping devices or external fields working collaboratively with special fluid properties to enable fluid motion. Natural liquid adhesion on surfaces deters motion and promotes the possibility of liquid or surface contamination. Despite progress, significant advancements are needed before devices for passive liquid propulsion, without the input of external energy and unwanted contamination, become a reality in applications. Here we present an unexplored and facile approach based on the Laplace pressure imbalance, manifesting itself through targeted track texturing, driving passively droplet motion, while maintaining the limited contact of the Cassie-Baxter state on superhydrophobic surfaces. The track topography resembles out-of-plane, backgammon-board, slowly converging microridges decorated with nanotexturing. This design naturally deforms asymmetrically the menisci formed at the bottom of a droplet contacting such tracks and causes a Laplace pressure imbalance that drives droplet motion. We investigate this effect over a range of opening track angles and develop a model to explain and quantify the underlying mechanism of droplet self-propulsion. We further implement the developed topography for applications relevant to microfluidic platform functionalities. We demonstrate control of the rebound angle of vertically impacting droplets, achieve horizontal self-transport to distances up to 65 times the droplet diameter, show significant uphill motion against gravity, and illustrate a self-driven droplet-merging process.
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11
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Milionis A, Tripathy A, Donati M, Sharma CS, Pan F, Maniura-Weber K, Ren Q, Poulikakos D. Water-Based Scalable Methods for Self-Cleaning Antibacterial ZnO-Nanostructured Surfaces. Ind Eng Chem Res 2020; 59:14323-14333. [PMID: 32831473 PMCID: PMC7434054 DOI: 10.1021/acs.iecr.0c01998] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 07/05/2020] [Accepted: 07/07/2020] [Indexed: 11/28/2022]
Abstract
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Bacterial
colonization poses significant health risks, such as
infestation of surfaces in biomedical applications and clean water
unavailability. If maintaining the surrounding water clean is a target,
developing surfaces with strong bactericidal action, which is facilitated
by bacterial access to the surface and mixing, can be a solution.
On the other hand, if sustenance of a surface free of bacteria is
the goal, developing surfaces with ultralow bacterial adhesion often
suffices. Here we report a facile, scalable, and environmentally benign
strategy that delivers customized surfaces for these challenges. For
bactericidal action, nanostructures of inherently antibacterial ZnO,
through simple immersion of zinc in hot water, are fabricated. The
resulting nanostructured surface exhibits extreme bactericidal effectiveness
(9250 cells cm–2 h–1) that eliminates
bacteria in direct contact and also remotely through the action of
reactive oxygen species. Remarkably, the remote bactericidal action
is achieved without the need for any illumination, otherwise required
in conventional approaches. As a result, ZnO nanostructures yield
outstanding water disinfection of >99.98%, in the dark, by inactivating
the bacteria within 3 h. Moreover, Zn2+ released to the
aqueous medium from the nanostructured ZnO surface have a concentration
of 0.73 ± 0.15 ppm, markedly below the legal limit for safe drinking
water (5–6 ppm). The same nanostructures, when hydrophobized
(through a water-based or fluorine-free spray process), exhibit strong
bacterial repulsion, thus substantially reducing bacterial adhesion.
Such environmentally benign and scalable methods showcase pathways
toward inhibiting surface bacterial colonization.
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Affiliation(s)
- Athanasios Milionis
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zürich, 8092 Zürich, Switzerland
| | - Abinash Tripathy
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zürich, 8092 Zürich, Switzerland
| | - Matteo Donati
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zürich, 8092 Zürich, Switzerland
| | - Chander Shekhar Sharma
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zürich, 8092 Zürich, Switzerland
| | - Fei Pan
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, 9014 St. Gallen, Switzerland
| | - Katharina Maniura-Weber
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, 9014 St. Gallen, Switzerland
| | - Qun Ren
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, 9014 St. Gallen, Switzerland
| | - Dimos Poulikakos
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zürich, 8092 Zürich, Switzerland
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Sombolos K, Pangalos M, Phassas A, Karamoschos K, Milionis A. Metastatic Ovarian-Cell Carcinoma of the Subcutaneous Tunnel during Intraperitoneal Chemotherapy. Perit Dial Int 2020. [DOI: 10.1177/089686088600600109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- K. Sombolos
- Dept of Internal Medicine of “G. Papanikolaou” General Hospital, Exochi, Thessaloniki Greece
| | - M. Pangalos
- Dept of Internal Medicine of “G. Papanikolaou” General Hospital, Exochi, Thessaloniki Greece
| | - A. Phassas
- Dept of Internal Medicine of “G. Papanikolaou” General Hospital, Exochi, Thessaloniki Greece
| | - K. Karamoschos
- Dept of Internal Medicine of “G. Papanikolaou” General Hospital, Exochi, Thessaloniki Greece
| | - A. Milionis
- Dept of Internal Medicine of “G. Papanikolaou” General Hospital, Exochi, Thessaloniki Greece
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13
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Li Z, Milionis A, Zheng Y, Yee M, Codispoti L, Tan F, Poulikakos D, Yap CH. Superhydrophobic hemostatic nanofiber composites for fast clotting and minimal adhesion. Nat Commun 2019; 10:5562. [PMID: 31804481 PMCID: PMC6895059 DOI: 10.1038/s41467-019-13512-8] [Citation(s) in RCA: 130] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 11/11/2019] [Indexed: 11/17/2022] Open
Abstract
Hemostatic materials are of great importance in medicine. However, their successful implementation is still challenging as it depends on two, often counteracting, attributes; achieving blood coagulation rapidly, before significant blood loss, and enabling subsequent facile wound-dressing removal, without clot tears and secondary bleeding. Here we illustrate an approach for achieving hemostasis, rationally targeting both attributes, via a superhydrophobic surface with immobilized carbon nanofibers (CNFs). We find that CNFs promote quick fibrin growth and cause rapid clotting, and due to their superhydrophobic nature they severely limit blood wetting to prevent blood loss and drastically reduce bacteria attachment. Furthermore, minimal contact between the clot and the superhydrophobic CNF surface yields an unforced clot detachment after clot shrinkage. All these important attributes are verified in vitro and in vivo with rat experiments. Our work thereby demonstrates that this strategy for designing hemostatic patch materials has great potential.
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Affiliation(s)
- Zhe Li
- Guangdong Provincial Key Laboratory of Sensor Technology and Biomedical Instrument, School of Biomedical Engineering, Sun Yat-Sen University, Guangzhou, 510006, China
- Department of Biomedical Engineering, National University of Singapore, Singapore, 117583, Singapore
| | - Athanasios Milionis
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich, 8092, Zurich, Switzerland
| | - Yu Zheng
- Department of Biomedical Engineering, National University of Singapore, Singapore, 117583, Singapore
| | - Marcus Yee
- Department of Biomedical Engineering, National University of Singapore, Singapore, 117583, Singapore
| | - Lukas Codispoti
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich, 8092, Zurich, Switzerland
| | - Freddie Tan
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, 117585, Singapore
| | - Dimos Poulikakos
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich, 8092, Zurich, Switzerland.
| | - Choon Hwai Yap
- Department of Biomedical Engineering, National University of Singapore, Singapore, 117583, Singapore.
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14
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Sharma CS, Lam CWE, Milionis A, Eghlidi H, Poulikakos D. Self-Sustained Cascading Coalescence in Surface Condensation. ACS Appl Mater Interfaces 2019; 11:27435-27442. [PMID: 31271531 PMCID: PMC6703749 DOI: 10.1021/acsami.9b07673] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 07/04/2019] [Indexed: 06/09/2023]
Abstract
Sustained dropwise condensation of water requires rapid shedding of condensed droplets from the surface. Here, we elucidate a microfluidic mechanism that spontaneously sweeps condensed microscale droplets without the need for the traditional droplet removal pathways such as use of superhydrophobicity for droplet rolling and jumping and utilization of wettability gradients for directional droplet transport among others. The mechanism involves self-generated, directional, cascading coalescence sequences of condensed microscale droplets along standard hydrophobic microgrooves. Each sequence appears like a spontaneous zipping process, can sweep droplets along the microgroove at speeds of up to ∼1 m/s, and can extend for lengths more than 100 times the microgroove width. We investigate this phenomenon through high-speed in situ microscale condensation observations and demonstrate that it is enabled by rapid oscillations of a condensate meniscus formed locally in a filled microgroove and pinned on its edges. Such oscillations are in turn spontaneously initiated by coalescence of an individual droplet growing on the ridge with the microgroove meniscus. We quantify the coalescence cascades by characterizing the size distribution of the swept droplets and propose a simple analytical model to explain the results. We also demonstrate that, as condensation proceeds on the hydrophobic microgrooved surface, the coalescence cascades recur spontaneously through repetitive dewetting of the microgrooves. Lastly, we identify surface design rules for consistent realization of the cascades. The hydrophobic microgrooved textures required for the activation of this mechanism can be realized through conventional, scalable surface fabrication methods on a broad range of materials (we demonstrate with aluminum and silicon), thus promising direct application in a host of phase-change processes.
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Walker C, Lerch S, Reininger M, Eghlidi H, Milionis A, Schutzius TM, Poulikakos D. Desublimation Frosting on Nanoengineered Surfaces. ACS Nano 2018; 12:8288-8296. [PMID: 30001108 DOI: 10.1021/acsnano.8b03554] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Ice nucleation from vapor presents a variety of challenges across a wide range of industries and applications including refrigeration, transportation, and energy generation. However, a rational comprehensive approach to fabricating intrinsically icephobic surfaces for frost formation-both from water condensation (followed by freezing) and in particular from desublimation (direct growth of ice crystals from vapor)-remains elusive. Here, guided by nucleation physics, we investigate the effect of material composition and surface texturing (atomically smooth to nanorough) on the nucleation and growth mechanism of frost for a range of conditions within the sublimation domain (0 °C to -55 °C; partial water vapor pressures 6 to 0.02 mbar). Surprisingly, we observe that on silicon at very cold temperatures-below the homogeneous ice solidification nucleation limit (<-46 °C)-desublimation does not become the favorable pathway to frosting. Furthermore, we show that surface nanoroughness makes frost formation on silicon more probable. We experimentally demonstrate at temperatures between -48 °C and -55 °C that nanotexture with radii of curvature within 1 order of magnitude of the critical radius of nucleation favors frost growth, facilitated by capillary condensation, consistent with Kelvin's equation. Our findings show that such nanoscale surface morphology imposed by design to impart desired functionalities-such as superhydrophobicity-or from defects can be highly detrimental for frost icephobicity at low temperatures and water vapor partial pressures (<0.05 mbar). Our work contributes to the fundamental understanding of phase transitions well within the equilibrium sublimation domain and has implications for applications such as travel, power generation, and refrigeration.
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Affiliation(s)
- Christopher Walker
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering , ETH Zurich , Sonneggstrasse 3 , CH-8092 Zurich , Switzerland
| | - Sebastian Lerch
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering , ETH Zurich , Sonneggstrasse 3 , CH-8092 Zurich , Switzerland
| | - Matthias Reininger
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering , ETH Zurich , Sonneggstrasse 3 , CH-8092 Zurich , Switzerland
| | - Hadi Eghlidi
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering , ETH Zurich , Sonneggstrasse 3 , CH-8092 Zurich , Switzerland
| | - Athanasios Milionis
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering , ETH Zurich , Sonneggstrasse 3 , CH-8092 Zurich , Switzerland
| | - Thomas M Schutzius
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering , ETH Zurich , Sonneggstrasse 3 , CH-8092 Zurich , Switzerland
| | - Dimos Poulikakos
- Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering , ETH Zurich , Sonneggstrasse 3 , CH-8092 Zurich , Switzerland
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16
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Milionis A, Krishnan KG, Loth E, Lawrence M. Dynamic wetting of human blood and plasma on various surfaces. Colloids Surf B Biointerfaces 2018; 166:218-223. [DOI: 10.1016/j.colsurfb.2018.03.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 02/24/2018] [Accepted: 03/19/2018] [Indexed: 12/23/2022]
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17
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Milionis A, Antonini C, Jung S, Nelson A, Schutzius TM, Poulikakos D. Contactless Transport and Mixing of Liquids on Self-Sustained Sublimating Coatings. Langmuir 2017; 33:1799-1809. [PMID: 28151671 DOI: 10.1021/acs.langmuir.6b04377] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Controlled handling of liquids and colloidal suspensions as they interact with surfaces, targeting a broad palette of related functionalities, is of great importance in science, technology, and nature. When small liquid volumes (drops on the order of microliters or nanoliters) need to be processed in microfluidic devices, contamination on the solid/liquid interface and loss of liquid due to adhesion on the transport channels are two very common problems that can significantly alter the process outcome, for example, the chemical reaction efficiency or the purity and the final concentration of a suspension. It is, therefore, no surprise that both levitation and minimal contact transport methods-including nonwetting surfaces-have been developed to minimize the interactions between liquids and surfaces. Here, we demonstrate contactless surface levitation and transport of liquid drops, realized by harnessing and sustaining the natural sublimation of a solid-carbon-dioxide-coated substrate to generate a continuous supporting vapor layer. The capability and limitations of this technique in handling liquids of extreme surface tension and kinematic viscosity values are investigated both experimentally and theoretically. The sublimating coating is capable of repelling many viscous and low-surface-tension liquids, colloidal suspensions, and non-Newtonian fluids as well, displaying outstanding omniphobic properties. Finally, we demonstrate how sublimation can be used for liquid transport, mixing, and drop coalescence, with a sublimating layer coated on an underlying substrate with prefabricated channels, conferring omniphobicity using a simple physical approach (i.e., phase change) rather than a chemical one. The independence of the surface levitation principle from material properties, such as electromagnetic, thermal or optical, surface energy, adhesion, or mechanical properties, renders this method attractive for a wide range of potential applications.
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Affiliation(s)
- Athanasios Milionis
- Laboratory of Thermodynamics in Emerging Technologies, Institute of Energy Technology, Department of Mechanical and Process Engineering, ETH Zürich , 8092 Zürich, Switzerland
| | - Carlo Antonini
- Laboratory of Thermodynamics in Emerging Technologies, Institute of Energy Technology, Department of Mechanical and Process Engineering, ETH Zürich , 8092 Zürich, Switzerland
- Empa, Swiss Federal Laboratories for Materials Science and Technology , Functional Cellulose Materials, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
| | - Stefan Jung
- Laboratory of Thermodynamics in Emerging Technologies, Institute of Energy Technology, Department of Mechanical and Process Engineering, ETH Zürich , 8092 Zürich, Switzerland
| | - Anders Nelson
- Laboratory of Thermodynamics in Emerging Technologies, Institute of Energy Technology, Department of Mechanical and Process Engineering, ETH Zürich , 8092 Zürich, Switzerland
| | - Thomas M Schutzius
- Laboratory of Thermodynamics in Emerging Technologies, Institute of Energy Technology, Department of Mechanical and Process Engineering, ETH Zürich , 8092 Zürich, Switzerland
| | - Dimos Poulikakos
- Laboratory of Thermodynamics in Emerging Technologies, Institute of Energy Technology, Department of Mechanical and Process Engineering, ETH Zürich , 8092 Zürich, Switzerland
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18
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Milionis A, Loth E, Bayer IS. Recent advances in the mechanical durability of superhydrophobic materials. Adv Colloid Interface Sci 2016; 229:57-79. [PMID: 26792021 DOI: 10.1016/j.cis.2015.12.007] [Citation(s) in RCA: 140] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2015] [Revised: 12/12/2015] [Accepted: 12/13/2015] [Indexed: 11/17/2022]
Abstract
Large majority of superhydrophobic surfaces have very limited mechanical wear robustness and long-term durability. This problem has restricted their utilization in commercial or industrial applications and resulted in extensive research efforts on improving resistance against various types of wear damage. In this review, advances and developments since 2011 in this field will be covered. As such, we summarize progress on fabrication, design and understanding of mechanically durable superhydrophobic surfaces. This includes an overview of recently published diagnostic techniques for probing and demonstrating tribo-mechanical durability against wear and abrasion as well as other effects such as solid/liquid spray or jet impact and underwater resistance. The review is organized in terms of various types of mechanical wear ranging from substrate adhesion, tangential surface abrasion, and dynamic impact to ultrasonic processing underwater. In each of these categories, we highlight the most successful approaches to produce robust surfaces that can maintain their non-wetting state after the wear or abrasive action. Finally, various recommendations for improvement of mechanical wear durability and its quantitative evaluation are discussed along with potential future directions towards more systematic testing methods which will also be acceptable for industry.
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Affiliation(s)
- Athanasios Milionis
- Mechanical and Aerospace Engineering, University of Virginia, 122 Engineer's Way, Charlottesville, VA 22904, United States.
| | - Eric Loth
- Mechanical and Aerospace Engineering, University of Virginia, 122 Engineer's Way, Charlottesville, VA 22904, United States.
| | - Ilker S Bayer
- Mechanical and Aerospace Engineering, University of Virginia, 122 Engineer's Way, Charlottesville, VA 22904, United States; Smart Materials/Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, Genoa 16163, Italy.
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19
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Yeong YH, Milionis A, Loth E, Sokhey J, Lambourne A. Atmospheric Ice Adhesion on Water-Repellent Coatings: Wetting and Surface Topology Effects. Langmuir 2015; 31:13107-13116. [PMID: 26566168 DOI: 10.1021/acs.langmuir.5b02725] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Recent studies have shown the potential of water-repellent surfaces such as superhydrophobic surfaces in delaying ice accretion and reducing ice adhesion. However, conflicting trends in superhydrophobic ice adhesion strength were reported by previous studies. Hence, this investigation was performed to study the ice adhesion strength of hydrophobic and superhydrophobic coatings under realistic atmospheric icing conditions, i.e., supercooled spray of 20 μm mean volume diameter (MVD) droplets in a freezing (-20 °C), thermally homogeneous environment. The ice was released in a tensile direction by underside air pressure in a Mode-1 ice fracture condition. Results showed a strong effect of water repellency (increased contact and receding angles) on ice adhesion strength for hydrophobic surfaces. However, the extreme water repellency of nanocomposite superhydrophobic surfaces did not provide further adhesion strength reductions. Rather, ice adhesion strength for superhydrophobic surfaces depended primarily on the surface topology spatial parameter of autocorrelation length (Sal), whereby surface features in close proximities associated with a higher capillary pressure were better able to resist droplet penetration. Effects from other surface height parameters (e.g., arithmetic mean roughness, kurtosis, and skewness) were secondary.
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Affiliation(s)
- Yong Han Yeong
- Department of Mechanical and Aerospace Engineering, University of Virginia , Charlottesville, Virginia 22904, United States
- Rolls-Royce North America, Indianapolis, Indiana 46241, United States
- Rolls-Royce, Plc. Derby DE24 8EJ, U.K
| | - Athanasios Milionis
- Department of Mechanical and Aerospace Engineering, University of Virginia , Charlottesville, Virginia 22904, United States
- Rolls-Royce North America, Indianapolis, Indiana 46241, United States
- Rolls-Royce, Plc. Derby DE24 8EJ, U.K
| | - Eric Loth
- Department of Mechanical and Aerospace Engineering, University of Virginia , Charlottesville, Virginia 22904, United States
- Rolls-Royce North America, Indianapolis, Indiana 46241, United States
- Rolls-Royce, Plc. Derby DE24 8EJ, U.K
| | - Jack Sokhey
- Department of Mechanical and Aerospace Engineering, University of Virginia , Charlottesville, Virginia 22904, United States
- Rolls-Royce North America, Indianapolis, Indiana 46241, United States
- Rolls-Royce, Plc. Derby DE24 8EJ, U.K
| | - Alexis Lambourne
- Department of Mechanical and Aerospace Engineering, University of Virginia , Charlottesville, Virginia 22904, United States
- Rolls-Royce North America, Indianapolis, Indiana 46241, United States
- Rolls-Royce, Plc. Derby DE24 8EJ, U.K
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Milionis A, Ruffilli R, Bayer IS. Superhydrophobic nanocomposites from biodegradable thermoplastic starch composites (Mater-Bi®), hydrophobic nano-silica and lycopodium spores. RSC Adv 2014. [DOI: 10.1039/c4ra04117h] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
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21
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Milionis A, Fragouli D, Martiradonna L, Anyfantis GC, Cozzoli PD, Bayer IS, Athanassiou A. Spatially controlled surface energy traps on superhydrophobic surfaces. ACS Appl Mater Interfaces 2014; 6:1036-1043. [PMID: 24386959 DOI: 10.1021/am404565a] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Water wetting and adhesion control on polymeric patterns are achieved by tuning the configuration of their surface's structural characteristics from single to dual and triple length-scale. In particular, surfaces with combined micro-, submicrometer-,and nanoroughness are developed, using photolithographically structured SU-8 micro-pillars as substrates for the consecutive spray deposition of polytetrafluoroethylene (PTFE) submicrometer particles and hydrophobically capped iron oxide colloidal nanoparticles. The PTFE particles alone or in combination with the nanoparticles render the SU-8 micropillars superhydrophobic. The water adhesion behaviour of the sprayed pillars is more complex since they can be tuned gradually from totally adhesive to completely non adhesive. The influence of the hierarchical geometrical features of the functionalized surfaces on this behaviour is discussed within the frame of the theory. Specially designed surfaces using the described technique are presented for selective drop deposition and evaporation. This simple method for liquid adhesion control on superhydrophobic surfaces can find various applications in the field of microfluidics, sensors, biotechnology, antifouling materials, etc.
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Affiliation(s)
- Athanasios Milionis
- Nanophysics, Istituto Italiano di Tecnologia (IIT) , Via Morego 30, 16163 Genova, Italy
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22
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Milionis A, Giannuzzi R, Bayer IS, Papadopoulou EL, Ruffilli R, Manca M, Athanassiou A. Self-cleaning organic/inorganic photo-sensors. ACS Appl Mater Interfaces 2013; 5:7139-7145. [PMID: 23815624 DOI: 10.1021/am401476k] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We present the fabrication of a multifunctional, hybrid organic-inorganic micropatterned device, which is capable to act as a stable photosensor and, at the same time, displaying inherent superhydrophobic self-cleaning wetting characteristics. In this framework several arrays of epoxy photoresist square micropillars have been fabricated on n-doped crystalline silicon substrates and subsequently coated with a poly(3-hexylthiophene-2,5-diyl) (P3HT) layer, giving rise to an array of organic/inorganic p-n junctions. Their photoconductivity has been measured under a solar light simulator at different illumination intensities. The current-voltage (I-V) curves show high rectifying characteristics, which are found to be directly correlated with the illumination intensity. The photoresponse occurs in extremely short times (within few tens of milliseconds range). The influence of the interpillar distance on the I-V characteristics of the sensors is also discussed. Moreover, the static and dynamic wetting properties of these organic/inorganic photosensors can be easily tuned by changing the pattern geometry. Measured static water contact angles range from 125° to 164°, as the distance between the pillars is increased from 14 to 120 μm while the contact angle hysteresis decreases from 36° down to 2°.
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Affiliation(s)
- Athanasios Milionis
- Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy.
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Milionis A, Martiradonna L, Anyfantis GC, Davide Cozzoli P, Bayer IS, Fragouli D, Athanassiou A. Control of the water adhesion on hydrophobic micropillars by spray coating technique. Colloid Polym Sci 2012. [DOI: 10.1007/s00396-012-2752-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Kalyva M, Bertoni G, Milionis A, Cingolani R, Athanassiou A. Tuning of the characteristics of Au nanoparticles produced by solid target laser ablation into water by changing the irradiation parameters. Microsc Res Tech 2010; 73:937-43. [PMID: 20872736 DOI: 10.1002/jemt.20868] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We report the production of Au nanoparticles with different average sizes and size distributions, by laser ablation of a solid Au target into pure deionized water. Tuning laser parameters such as pulse duration, energy, and wavelength is possible to tune the size and the size distributions of the produced nanoparticles into the liquid. We demonstrate the possibility of production of highly monodispersed colloidal solutions, in which the average nanoparticle size ranges from 3 to 10 nm, using laser pulses of ns duration. Laser ablation using fs laser pulses can also produce very small nanoparticles, although a small population of bigger nanoparticles is always present. Low and high-resolution transmission electron microscopy (TEM), in combination with UV-Vis spectroscopy have been employed for the characterization of our samples.
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Affiliation(s)
- Maria Kalyva
- Center of Biomolecular Nanotechnologies, Italian Institute of Technology, via Barsanti 1, Arnesano, Lecce, Italy.
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Spaia S, Pangalos M, Askepidis N, Pazarloglou M, Mavropoulou E, Theodoridis S, Dimitrakopoulos K, Milionis A, Vayonas G. Effect of short-term rHuEPO treatment on insulin resistance in haemodialysis patients. Nephron Clin Pract 2000; 84:320-5. [PMID: 10754408 DOI: 10.1159/000045606] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIM Decreased sensitivity to the hypoglycaemic action of insulin is an almost universal phenomenon in uraemic patients, and it is attributed either to uraemic toxins or to anaemia or even to secondary hyperparathyroidism. Considering the conflicting data of few existing studies, we examined the influence of erythropoietin (EPO) treatment on insulin resistance and tested the probable correlation of this influence with sympathetic nervous system (SNS) activity. METHODS We studied 8 non-obese, non-diabetic, stable dialysis patients using the euglycaemic insulin clamp technique before administration of EPO (phase A), 10 days after (phase B), and after the correction of the haematocrit level, at least 8 weeks later (phase C). We estimated the indices (glucose infusion rate, mg/kg/min), M/G (glucose clearance), and M/I (tissue sensitivity to insulin), and we measured haematocrit, haemoglobin, triglyceride, ferritin, EPO, and fasting insulin levels in each phase. During each phase, we tested the SNS activity using the response of blood pressure to persistent handgrip and the response of blood pressure to the standing position. RESULTS Our patients appeared to have an increased insulin resistance in phase A (M(A) = 6.24 +/- 1.01) which was significantly improved 10 days after the beginning of EPO treatment and before the rise of haematocrit (M(B) = 7.71 +/- 1.54, p < 0.05). There was no further improvement in phase C. Indices M/G and M/I behaved similarly. The serum triglyceride levels decreased in response to the increased insulin sensitivity. The patients studied did not demonstrate fasting hyperinsulinaemia, while the SNS activity was abnormal and remained unchanged throughout the study period in spite of some individual improvement. CONCLUSIONS Our study proves the beneficial effect of EPO treatment on insulin resistance in dialysis patients which could be attributed to the EPO itself and not to the correction of anaemia and is accompanied by improvement in triglyceride levels. Amelioration of insulin resistance did not influence the SNS activity, making the association between EPO treatment and SNS-derived changes in blood pressure quite improbable.
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Affiliation(s)
- S Spaia
- Renal Department, Second Hospital of IKA, Thessaloniki, Greece
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Papadimitriou M, Vyzantiadis A, Milionis A, Memmos D, Metaxas P. The effect of spironolactone in hypertensive patients on regular haemodialysis and after renal allotransplantation. Life Support Syst 1983; 1:197-205. [PMID: 6433115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
To determine the role of the renin-angiotensin-aldosterone system in the maintenance of hypertension in patients with end stage renal disease, twenty four hypertensive patients were studied on regular haemodialysis treatment (RDT) and after successful kidney transplantation. The first group consisted of nine patients on RDT with their own kidneys in situ, and the second group consisted of nine kidney transplants. All 18 patients were given spironolactone 300 mg daily for three weeks following a control period of the same duration. In addition, three anephric patients on RDT were studied with the above protocol and three other patients on RDT were given the same dose for only six days. Blood pressure (BP), body weight, plasma K-Na, aldosterone and renin activity in all patients, and Na and aldosterone in urine in the second group were measured. In the first group of patients on RDT plasma potassium and renin activity increased significantly but BP remained unchanged. In the second group of transplanted patients plasma potassium, renin activity, and aldosterone were increased and BP diminished significantly. In the group of three anephric patients plasma potassium increased but plasma renin activity remained very low. Finally, in the patients on dialysis who received spironolactone for only six days there was a parallel increase of serum potassium and plasma renin activity. These findings suggest that in patients on RDT spironolactone stimulates renin secretion and potassium retention possibly by an effect on the remaining nephrons and/or the intestinal wall. On the contrary, in the transplanted patients the effect of spironolactone on the renal tubule is capable of producing sodium depletion and fall in BP.
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Papadimitriou M, Milionis A, Sakellariou G, Metaxas P. Effect of furosemide on acut ischaemic renal failure in the dog. Nephron Clin Pract 1978; 20:157-62. [PMID: 628497 DOI: 10.1159/000181214] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The effect of furosemide on the development of the acute ischaemic renal failure in the dog was studied. 11 canine kidneys were used as controls (group I) and 12 as a group where furosemide (6-8 mg/kg of body weight) was given (group II) immediately after releasing the clamps. Urine volume and sodium clearance were found significantly higher in the second group of kidneys during a period of 60 min after restoration of the blood flow to the kidney. Urea clearances remained low with no noted difference between the 2 groups. By the end of the first hour osmolar and potassium clearances were found to be significantly higher in the second group. The above findings suggest that furosemide given after an induction of acute ischaemic renal failure in the dog provides, up to the 1st hour after recirculation, some benefit in water and solute excretion but no benefit in urea clearance.
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