Capillary Rise of Nanostructured Microwicks
Capillarity refers to the driving force to propel liquid through small gaps in the absence of external forces, and hence enhanced capillary force has been pursued for various applications. In this study, flower like ZnO nanostructures are successfully deposited to enhance capillarity of microwick st...
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doaj-e13f023daca841ed81739c15cbe5b32d2020-11-25T00:43:25ZengMDPI AGMicromachines2072-666X2018-03-019415310.3390/mi9040153mi9040153Capillary Rise of Nanostructured MicrowicksChang-Ho Choi0Shankar Krishnan1Ward TeGrotenhuis2Chih-Hung Chang3School of Chemical, Biological, and Environmental Engineering, Oregon State University, Corvallis, OR 97331, USABattelle/Pacific Northwest National Laboratory, MicroProducts Breakthrough Institute, 1000 NE Circle Boulevard, Suite 11101, Corvallis, OR 97330, USABattelle/Pacific Northwest National Laboratory, MicroProducts Breakthrough Institute, 1000 NE Circle Boulevard, Suite 11101, Corvallis, OR 97330, USASchool of Chemical, Biological, and Environmental Engineering, Oregon State University, Corvallis, OR 97331, USACapillarity refers to the driving force to propel liquid through small gaps in the absence of external forces, and hence enhanced capillary force has been pursued for various applications. In this study, flower like ZnO nanostructures are successfully deposited to enhance capillarity of microwick structures that are specially designed to augment boiling heat transfer performance. Microreactor-assisted nanomaterial deposition, MANDTM, is employed with a flow cell to deposit the ZnO nanostructures on a large sized microwick (4.3 cm × 10.7 cm) with dual-channel configuration. A capillary rise experiment based on the mass gain method is first performed using water and ethanol (EtOH) as the working liquids to demonstrate the enhanced capillary force induced by the ZnO nanostructure on the microwick structure. It is found that the coating of ZnO nanostructure effectively propels the working fluids through the nano- or micro pores created from the ZnO nanostructure and consequently improves the capillary force. In order to investigate the wicking mechanism of the ZnO coated microwick structure, the capillary rise result based on height measurement was compared with analytical models. It is found that the gravity effect and viscous force play an important role in wicking rise of the coated wick structure. This study aims at demonstrating the capability of the integrated MAND process with a flow cell for producing a large scaled nanostructured surface, which eventually has a great potential for enhanced boiling heat transfer.http://www.mdpi.com/2072-666X/9/4/153ZnO nanostructurecapillary wickingZnO nanoparticle assembly |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Chang-Ho Choi Shankar Krishnan Ward TeGrotenhuis Chih-Hung Chang |
spellingShingle |
Chang-Ho Choi Shankar Krishnan Ward TeGrotenhuis Chih-Hung Chang Capillary Rise of Nanostructured Microwicks Micromachines ZnO nanostructure capillary wicking ZnO nanoparticle assembly |
author_facet |
Chang-Ho Choi Shankar Krishnan Ward TeGrotenhuis Chih-Hung Chang |
author_sort |
Chang-Ho Choi |
title |
Capillary Rise of Nanostructured Microwicks |
title_short |
Capillary Rise of Nanostructured Microwicks |
title_full |
Capillary Rise of Nanostructured Microwicks |
title_fullStr |
Capillary Rise of Nanostructured Microwicks |
title_full_unstemmed |
Capillary Rise of Nanostructured Microwicks |
title_sort |
capillary rise of nanostructured microwicks |
publisher |
MDPI AG |
series |
Micromachines |
issn |
2072-666X |
publishDate |
2018-03-01 |
description |
Capillarity refers to the driving force to propel liquid through small gaps in the absence of external forces, and hence enhanced capillary force has been pursued for various applications. In this study, flower like ZnO nanostructures are successfully deposited to enhance capillarity of microwick structures that are specially designed to augment boiling heat transfer performance. Microreactor-assisted nanomaterial deposition, MANDTM, is employed with a flow cell to deposit the ZnO nanostructures on a large sized microwick (4.3 cm × 10.7 cm) with dual-channel configuration. A capillary rise experiment based on the mass gain method is first performed using water and ethanol (EtOH) as the working liquids to demonstrate the enhanced capillary force induced by the ZnO nanostructure on the microwick structure. It is found that the coating of ZnO nanostructure effectively propels the working fluids through the nano- or micro pores created from the ZnO nanostructure and consequently improves the capillary force. In order to investigate the wicking mechanism of the ZnO coated microwick structure, the capillary rise result based on height measurement was compared with analytical models. It is found that the gravity effect and viscous force play an important role in wicking rise of the coated wick structure. This study aims at demonstrating the capability of the integrated MAND process with a flow cell for producing a large scaled nanostructured surface, which eventually has a great potential for enhanced boiling heat transfer. |
topic |
ZnO nanostructure capillary wicking ZnO nanoparticle assembly |
url |
http://www.mdpi.com/2072-666X/9/4/153 |
work_keys_str_mv |
AT changhochoi capillaryriseofnanostructuredmicrowicks AT shankarkrishnan capillaryriseofnanostructuredmicrowicks AT wardtegrotenhuis capillaryriseofnanostructuredmicrowicks AT chihhungchang capillaryriseofnanostructuredmicrowicks |
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