TY - JOUR
T1 - Influence of surface wettability and nanostructure on the generation of interfacial nanobubbles
AU - Teshima, Hideaki
AU - Nishiyama, Takashi
AU - Takata, Yasuyuki
AU - Takahashi, Koji
N1 - Funding Information:
This work was partially supported by JSPS KAKENHI Grant Numbers JP16H02315, JP16H04280, JP16K06126, JP16K14174, and JP17H03186. PF-QNM measurements were performed at the Center of Advanced Instrumental Analysis, Kyushu University.
Publisher Copyright:
© 2018 International Heat Transfer Conference. All rights reserved.
PY - 2018
Y1 - 2018
N2 - Interfacial nanobubbles were first speculated in 1994 and experimentally confirmed in 2000 by atomic force microscopy (AFM) measurements. It was recently proposed that the onset of boiling with the very low superheat on hydrophobic surface could be explained by assuming the existence of interfacial nanobubbles. To reduce the superheat and enhance the reliability of boiling heat transfer, the control of the generation of interfacial nanobubbles is indispensable. In this study, we measured the interfacial nanobubbles by AFM and examined the influence of surface wettability and nanostructure on their generation. First, we measured the spherical-cap shaped nanobubbles generated on the HOPG surface. It was observed that the nanobubbles only generate on the hydrophobic terraced area and do not cross the nanosized hydrophilic steps. Next, we prepared the hydrophilic-hydrophobic hybrid surfaces and generated the nanobubbles on those. As a result, the range of nanobubble generation clearly changed by the difference of wettability between adjacent surfaces. These results show that the generation of interfacial nanobubbles can be controlled by the surface processing of the substrate and can be expected to be applied to boiling heat transfer.
AB - Interfacial nanobubbles were first speculated in 1994 and experimentally confirmed in 2000 by atomic force microscopy (AFM) measurements. It was recently proposed that the onset of boiling with the very low superheat on hydrophobic surface could be explained by assuming the existence of interfacial nanobubbles. To reduce the superheat and enhance the reliability of boiling heat transfer, the control of the generation of interfacial nanobubbles is indispensable. In this study, we measured the interfacial nanobubbles by AFM and examined the influence of surface wettability and nanostructure on their generation. First, we measured the spherical-cap shaped nanobubbles generated on the HOPG surface. It was observed that the nanobubbles only generate on the hydrophobic terraced area and do not cross the nanosized hydrophilic steps. Next, we prepared the hydrophilic-hydrophobic hybrid surfaces and generated the nanobubbles on those. As a result, the range of nanobubble generation clearly changed by the difference of wettability between adjacent surfaces. These results show that the generation of interfacial nanobubbles can be controlled by the surface processing of the substrate and can be expected to be applied to boiling heat transfer.
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U2 - 10.1615/ihtc16.nmt.022210
DO - 10.1615/ihtc16.nmt.022210
M3 - Conference article
AN - SCOPUS:85068337214
SN - 2377-424X
VL - 2018-August
SP - 6909
EP - 6914
JO - International Heat Transfer Conference
JF - International Heat Transfer Conference
T2 - 16th International Heat Transfer Conference, IHTC 2018
Y2 - 10 August 2018 through 15 August 2018
ER -