1
|
Ho JY, Rabbi KF, Khodakarami S, Sett S, Wong TN, Leong KC, King WP, Miljkovic N. Ultrascalable Surface Structuring Strategy of Metal Additively Manufactured Materials for Enhanced Condensation. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2104454. [PMID: 35780492 PMCID: PMC9404399 DOI: 10.1002/advs.202104454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 05/07/2022] [Indexed: 06/15/2023]
Abstract
Metal additive manufacturing (AM) enables unparalleled design freedom for the development of optimized devices in a plethora of applications. The requirement for the use of nonconventional aluminum alloys such as AlSi10Mg has made the rational micro/nanostructuring of metal AM challenging. Here, the techniques are developed and the fundamental mechanisms governing the micro/nanostructuring of AlSi10Mg, the most common metal AM material, are investigated. A surface structuring technique is rationally devised to form previously unexplored two-tier nanoscale architectures that enable remarkably low adhesion, excellent resilience to condensation flooding, and enhanced liquid-vapor phase transition. Using condensation as a demonstration framework, it is shown that the two-tier nanostructures achieve 6× higher heat transfer coefficient when compared to the best filmwise condensation. The study demonstrates that AM-enabled nanostructuring is optimal for confining droplets while reducing adhesion to facilitate droplet detachment. Extensive benchmarking with past reported data shows that the demonstrated heat transfer enhancement has not been achieved previously under high supersaturation conditions using conventional aluminum, further motivating the need for AM nanostructures. Finally, it has been demonstrated that the synergistic combination of wide AM design freedom and optimal AM nanostructuring method can provide an ultracompact condenser having excellent thermal performance and power density.
Collapse
Affiliation(s)
- Jin Yao Ho
- Department of Mechanical Science and EngineeringUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
- Singapore Centre for 3D PrintingSchool of Mechanical and Aerospace EngineeringNanyang Technological University50 Nanyang AvenueSingapore639798Singapore
| | - Kazi Fazle Rabbi
- Department of Mechanical Science and EngineeringUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
| | - Siavash Khodakarami
- Department of Mechanical Science and EngineeringUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
| | - Soumyadip Sett
- Department of Mechanical Science and EngineeringUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
| | - Teck Neng Wong
- Singapore Centre for 3D PrintingSchool of Mechanical and Aerospace EngineeringNanyang Technological University50 Nanyang AvenueSingapore639798Singapore
| | - Kai Choong Leong
- Singapore Centre for 3D PrintingSchool of Mechanical and Aerospace EngineeringNanyang Technological University50 Nanyang AvenueSingapore639798Singapore
| | - William P King
- Department of Mechanical Science and EngineeringUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
- Department of Electrical and Computer EngineeringUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
- Materials Research LaboratoryUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
| | - Nenad Miljkovic
- Department of Mechanical Science and EngineeringUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
- Department of Electrical and Computer EngineeringUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
- Materials Research LaboratoryUniversity of Illinois at Urbana‐ChampaignUrbanaIL61801USA
- International Institute for Carbon Neutral Energy Research (WPI‐I2CNER)Kyushu University744 Moto‐okaNishi‐kuFukuoka819‐0395Japan
| |
Collapse
|
2
|
Wang R, Jakhar K, Ahmed S, Antao DS. Elucidating the Mechanism of Condensation-Mediated Degradation of Organofunctional Silane Self-Assembled Monolayer Coatings. ACS APPLIED MATERIALS & INTERFACES 2021; 13:34923-34934. [PMID: 34264646 DOI: 10.1021/acsami.1c08496] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Dropwise condensation is favorable for numerous industrial and heat/mass transfer applications due to the enhanced heat transfer performance that results from efficient condensate removal. Organofunctional silane self-assembled monolayer (SAM) coatings are one of the most common ultrathin low surface energy materials used to promote dropwise condensation of water vapors because of their minimal thermal resistance and scalable synthesis process. These SAM coatings typically degrade (i.e., condensation transitions from the efficient dropwise mode to the inefficient filmwise mode) rapidly during water vapor condensation. More importantly, the condensation-mediated coating degradation/failure mechanism(s) remain unknown and/or unproven. In this work, we develop a mechanistic understanding of water vapor condensation-mediated organofunctional silane SAM coating degradation and validate our hypothesis through controlled coating synthesis procedures on silicon/silicon dioxide substrates. We further demonstrate that a pristine organofunctional silane SAM coating resulting from a water/moisture-free coating environment exhibits superior long-term robustness during water vapor condensation. Our molecular/nanoscale surface characterizations, pre- and post-condensation heat transfer testing, indicate that the presence of moisture in the coating environment leads to uncoated regions of the substrate that act as nucleation sites for coating degradation. By elucidating the reasons for formation of these degradation nuclei and demonstrating a method to suppress such defects, this study provides new insight into why low surface energy silane SAM coatings degrade during water vapor condensation. The proposed approach addresses a key bottleneck (i.e., coating failure) preventing the adoption of efficient dropwise condensation methods in industry, and it will facilitate enhanced phase-change heat transfer technologies in industrial applications.
Collapse
Affiliation(s)
- Ruisong Wang
- J. Mike Walker'66 Department of Mechanical Engineering, Texas A&M University, College Station, Texas 77843-3123, United States
| | - Karan Jakhar
- J. Mike Walker'66 Department of Mechanical Engineering, Texas A&M University, College Station, Texas 77843-3123, United States
| | - Shoaib Ahmed
- J. Mike Walker'66 Department of Mechanical Engineering, Texas A&M University, College Station, Texas 77843-3123, United States
| | - Dion S Antao
- J. Mike Walker'66 Department of Mechanical Engineering, Texas A&M University, College Station, Texas 77843-3123, United States
| |
Collapse
|
3
|
Wen R, Liu W, Ma X, Yang R. Coupling droplets/bubbles with a liquid film for enhancing phase-change heat transfer. iScience 2021; 24:102531. [PMID: 34113838 PMCID: PMC8170143 DOI: 10.1016/j.isci.2021.102531] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Evaporation, boiling, and condensation are fundamental liquid-vapor phase-change heat transfer processes and have been utilized in many conventional and emerging energy systems. Recent advances in the manipulation of interface wetting and heterogeneous nucleation using micro/nano-structured surfaces have enabled exciting two-phase flow dynamics and heat transfer enhancement. However, independently manipulating droplets, bubbles, or liquid films through surface modification has encountered bottlenecks. In this Perspective, we discuss an emerging strategy where droplets/bubbles are coupled with a liquid film to control fluid dynamics for minimizing the thermal resistance between the liquid-vapor interface and solid substrate, thus significantly enhancing the heat transfer performance beyond the state of the art.
Collapse
Affiliation(s)
- Rongfu Wen
- State Key Laboratory of Fine Chemicals, Liaoning Key Laboratory of Clean Utilization of Chemical Resources, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China
| | - Wei Liu
- School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xuehu Ma
- State Key Laboratory of Fine Chemicals, Liaoning Key Laboratory of Clean Utilization of Chemical Resources, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China
| | - Ronggui Yang
- School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| |
Collapse
|
4
|
Enhanced condensation heat transfer using porous silica inverse opal coatings on copper tubes. Sci Rep 2021; 11:10675. [PMID: 34021211 PMCID: PMC8140112 DOI: 10.1038/s41598-021-90015-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 04/16/2021] [Indexed: 11/22/2022] Open
Abstract
Phase-change condensation is commonplace in nature and industry. Since the 1930s, it is well understood that vapor condenses in filmwise mode on clean metallic surfaces whereas it condenses by forming discrete droplets on surfaces coated with a promoter material. In both filmwise and dropwise modes, the condensate is removed when gravity overcomes pinning forces. In this work, we show rapid condensate transport through cracks that formed due to material shrinkage when a copper tube is coated with silica inverse opal structures. Importantly, the high hydraulic conductivity of the cracks promote axial condensate transport that is beneficial for condensation heat transfer. In our experiments, the cracks improved the heat transfer coefficient from ≈ 12 kW/m2 K for laminar filmwise condensation on smooth clean copper tubes to ≈ 80 kW/m2 K for inverse opal coated copper tubes; nearly a sevenfold increase from filmwise condensation and identical enhancement with state-of-the-art dropwise condensation. Furthermore, our results show that impregnating the porous structure with oil further improves the heat transfer coefficient by an additional 30% to ≈ 103 kW/m2 K. Importantly, compared to the fast-degrading dropwise condensation, the inverse opal coated copper tubes maintained high heat transfer rates when the experiments were repeated > 20 times; each experiment lasting 3–4 h. In addition to the new coating approach, the insights gained from this work present a strategy to minimize oil depletion during condensation from lubricated surfaces.
Collapse
|
5
|
Lettieri M, Masieri M, Frigione M. Novel Nano-Filled Coatings for the Protection of Built Heritage Stone Surfaces. NANOMATERIALS 2021; 11:nano11020301. [PMID: 33503902 PMCID: PMC7912206 DOI: 10.3390/nano11020301] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 01/19/2021] [Accepted: 01/20/2021] [Indexed: 11/16/2022]
Abstract
An experimental nano-filled coating, based on a fluorine resin containing SiO2 nano-particles, was applied on calcareous stones, representative of materials used in buildings and monuments of the Mediterranean basin; for comparison purposes, two commercial products were applied on the same substrates. The efficacy of the protective treatments was assessed by analyzing different characteristics of the three experimental/commercial products, i.e., color changes and permeability to water vapor to evaluate the treatments’ harmlessness; capillary water absorption and water stone contact angle to evaluate the protection against water ingress; oleophobicity of the treated surfaces and the behavior under staining by acrylic blue-colored spray paint and felt-tip marker to verify the anti-graffiti action. Finally, the properties of the treated stone surfaces were analyzed also after the application of pancreatin, used to simulate bird excreta (guano). The protective coatings were found to promote graffiti removal, reducing also the detrimental effects due to simulated guano. The experimental nano-filled product, in addition, was able to provide outstanding performance but using smaller amounts of product in comparison to commercial systems.
Collapse
Affiliation(s)
- Mariateresa Lettieri
- CNR–SPIN, SuPerconducting and Other INnovative Materials and Devices Institute, via Giovanni Paolo II 132, 84084 Fisciano, Salerno, Italy
- Correspondence:
| | - Maurizio Masieri
- CNR–ISPC, Istituto di Scienze del Patrimonio Culturale, Prov.le Lecce-Monteroni, 73100 Lecce, Italy;
| | - Mariaenrica Frigione
- Department of Innovation Engineering, University of Salento, Prov.le Lecce-Monteroni, 73100 Lecce, Italy;
| |
Collapse
|
6
|
Wilke KL, Antao DS, Cruz S, Iwata R, Zhao Y, Leroy A, Preston DJ, Wang EN. Polymer Infused Porous Surfaces for Robust, Thermally Conductive, Self-Healing Coatings for Dropwise Condensation. ACS NANO 2020; 14:14878-14886. [PMID: 33185426 DOI: 10.1021/acsnano.0c03961] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Hydrophobic coatings with low thermal resistance promise a significant enhancement in condensation heat transfer performance by promoting dropwise condensation in applications including power generation, water treatment, and thermal management of high-performance electronics. However, after nearly a century of research, coatings with adequate robustness remain elusive due to the extreme environments within many condensers and strict design requirements needed to achieve enhancement. In this work, we enable long-lasting condensation heat transfer enhancement via dropwise condensation by infusing a hydrophobic polymer, Teflon AF, into a porous nanostructured surface. This polymer infused porous surface (PIPS) uses the large surface area of the nanostructures to enhance polymer adhesion, while the nanostructures form a percolated network of high thermal conductivity material throughout the polymer and drastically reduce the thermal resistance of the composite. We demonstrate over 700% enhancement in the condensation of steam compared to an uncoated surface. This performance enhancement was sustained for more than 200 days without significant degradation. Furthermore, we show that the surfaces are self-repairing upon raising the temperature past the melting point of the polymer, allowing recovery of hydrophobicity and offering a level of durability more appropriate for industrial applications.
Collapse
Affiliation(s)
- Kyle L Wilke
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Dion S Antao
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Samuel Cruz
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Ryuichi Iwata
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Yajing Zhao
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Arny Leroy
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Daniel J Preston
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Evelyn N Wang
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| |
Collapse
|
7
|
Wang R, Jakhar K, Antao DS. Unified Modeling Framework for Thin-Film Evaporation from Micropillar Arrays Capturing Local Interfacial Effects. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:12927-12935. [PMID: 31525296 DOI: 10.1021/acs.langmuir.9b02048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Thin-film evaporation from micropillar array porous media has gained attention in a number of fields including energy conversion and thermal management of electronics. Performance in these applications is enhanced by leveraging the geometries of the micropillar arrays to both optimize flow through these arrays via capillary pumping and increase the curved liquid-vapor interface (meniscus) area for active phase-change heat transfer. In this work, we present a unified semianalytical modeling framework to predict the dry-out heat flux accurately for thin-film evaporation from micropillar arrays with the precise prediction of (i) the pressure profile along the wick achieved by discretizing the porous media domain and (ii) the local permeability that depends on the local meniscus shape. We validate the permeability model with 3D numerical simulations and verify the accuracy of the thin-film evaporation modeling framework with available experimental data from the literature. We emphasize the importance of predicting an accurate liquid-vapor interface shape for the prediction accuracy of both the permeability and the associated governing equations for liquid propagation and phase-change heat transfer through porous materials. This modeling framework is an accurate non-CFD-based methodology for predicting the dry-out heat flux during thin-film evaporation from micropillar arrays and will serve as a general framework for modeling steady liquid-vapor phase-change processes (evaporation and condensation) in porous media.
Collapse
Affiliation(s)
- Ruisong Wang
- J. Mike Walker '66 Department of Mechanical Engineering , Texas A&M University , College Station , Texas 77843-3123 , United States
| | - Karan Jakhar
- J. Mike Walker '66 Department of Mechanical Engineering , Texas A&M University , College Station , Texas 77843-3123 , United States
| | - Dion S Antao
- J. Mike Walker '66 Department of Mechanical Engineering , Texas A&M University , College Station , Texas 77843-3123 , United States
| |
Collapse
|