Impact of microcapsules wettability on thermal conductivity of microencapsulated phase change material(MPCM) suspensions
The purpose of this paper is to investigate the effect of the wettability on MPCM suspensions thermal conductivity. The wettability of the capsules, characterized by contact angle between solid capsules and carrying fluid, was modified by mixing two selected surfactants into the suspensions, i.e.,ce...
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| Format: | Article |
| Language: | English |
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The Japan Society of Mechanical Engineers
2018-01-01
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| Series: | Journal of Thermal Science and Technology |
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| Online Access: | https://www.jstage.jst.go.jp/article/jtst/13/1/13_2018jtst0002/_pdf/-char/en |
| _version_ | 1819183189816508416 |
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| author | Zhongzhu QIU Chengfang QIN Weiting JIANG Puyan ZHENG Tao ZHANG Chengyao WANG Chunying LI |
| author_facet | Zhongzhu QIU Chengfang QIN Weiting JIANG Puyan ZHENG Tao ZHANG Chengyao WANG Chunying LI |
| author_sort | Zhongzhu QIU |
| collection | DOAJ |
| description | The purpose of this paper is to investigate the effect of the wettability on MPCM suspensions thermal conductivity. The wettability of the capsules, characterized by contact angle between solid capsules and carrying fluid, was modified by mixing two selected surfactants into the suspensions, i.e.,cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate(SDS) and changing such surfactants’ additive amount. Meanwhile, the Hot Disk 2500s thermal analyzer was applied to test the static thermal conductivity of the MPCM suspensions in which the mass fraction of capsules is 10wt.% and obtained the relation between the thermal conductivity and the contact angle. The results indicated, when the mass fraction of surfactants falls into the range of 0 -0.05wt.%, the effect of the CTAB is more significant than the SDS. However, when the mass fraction of surfactants continue to increase from 0.05wt.%, the significance of the SDS exceeded the CTAB. It was also found that the decrease in the contact angle led to the growth in thermal conductivity for both Maxwell model’s theoretical value and experimental results. When the contact angle fell into the range of 45°-95°, the Maxwell model’s theoretical results of the thermal conductivity could predict the thermal conductivity of MPCM suspensions with a good accuracy, but inversely when the contact angles were smaller than 45°, a significant gap was found between the two results. To remove such gap a correction factor “A” which is associated with contact angles was proposed. |
| first_indexed | 2024-12-22T22:58:04Z |
| format | Article |
| id | doaj.art-a177e0b05c304e07a97edd474e84a6ca |
| institution | Directory Open Access Journal |
| issn | 1880-5566 |
| language | English |
| last_indexed | 2024-12-22T22:58:04Z |
| publishDate | 2018-01-01 |
| publisher | The Japan Society of Mechanical Engineers |
| record_format | Article |
| series | Journal of Thermal Science and Technology |
| spelling | doaj.art-a177e0b05c304e07a97edd474e84a6ca2022-12-21T18:09:45ZengThe Japan Society of Mechanical EngineersJournal of Thermal Science and Technology1880-55662018-01-01131JTST0002JTST000210.1299/jtst.2018jtst0002jtstImpact of microcapsules wettability on thermal conductivity of microencapsulated phase change material(MPCM) suspensionsZhongzhu QIU0Chengfang QIN1Weiting JIANG2Puyan ZHENG3Tao ZHANG4Chengyao WANG5Chunying LI6College of Energy and Mechanical Engineering, Shanghai University of Electric PowerCollege of Energy and Mechanical Engineering, Shanghai University of Electric PowerCollege of Energy and Mechanical Engineering, Shanghai University of Electric PowerCollege of Energy and Mechanical Engineering, Shanghai University of Electric PowerCollege of Energy and Mechanical Engineering, Shanghai University of Electric PowerCollege of Energy and Mechanical Engineering, Shanghai University of Electric PowerCollege of Real Estate, Beijing Normal University, ZhuhaiThe purpose of this paper is to investigate the effect of the wettability on MPCM suspensions thermal conductivity. The wettability of the capsules, characterized by contact angle between solid capsules and carrying fluid, was modified by mixing two selected surfactants into the suspensions, i.e.,cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate(SDS) and changing such surfactants’ additive amount. Meanwhile, the Hot Disk 2500s thermal analyzer was applied to test the static thermal conductivity of the MPCM suspensions in which the mass fraction of capsules is 10wt.% and obtained the relation between the thermal conductivity and the contact angle. The results indicated, when the mass fraction of surfactants falls into the range of 0 -0.05wt.%, the effect of the CTAB is more significant than the SDS. However, when the mass fraction of surfactants continue to increase from 0.05wt.%, the significance of the SDS exceeded the CTAB. It was also found that the decrease in the contact angle led to the growth in thermal conductivity for both Maxwell model’s theoretical value and experimental results. When the contact angle fell into the range of 45°-95°, the Maxwell model’s theoretical results of the thermal conductivity could predict the thermal conductivity of MPCM suspensions with a good accuracy, but inversely when the contact angles were smaller than 45°, a significant gap was found between the two results. To remove such gap a correction factor “A” which is associated with contact angles was proposed.https://www.jstage.jst.go.jp/article/jtst/13/1/13_2018jtst0002/_pdf/-char/enmicroencapsulated phase change material suspensionscontact anglethermal conductivitymaxwell formulacorrection factor |
| spellingShingle | Zhongzhu QIU Chengfang QIN Weiting JIANG Puyan ZHENG Tao ZHANG Chengyao WANG Chunying LI Impact of microcapsules wettability on thermal conductivity of microencapsulated phase change material(MPCM) suspensions Journal of Thermal Science and Technology microencapsulated phase change material suspensions contact angle thermal conductivity maxwell formula correction factor |
| title | Impact of microcapsules wettability on thermal conductivity of microencapsulated phase change material(MPCM) suspensions |
| title_full | Impact of microcapsules wettability on thermal conductivity of microencapsulated phase change material(MPCM) suspensions |
| title_fullStr | Impact of microcapsules wettability on thermal conductivity of microencapsulated phase change material(MPCM) suspensions |
| title_full_unstemmed | Impact of microcapsules wettability on thermal conductivity of microencapsulated phase change material(MPCM) suspensions |
| title_short | Impact of microcapsules wettability on thermal conductivity of microencapsulated phase change material(MPCM) suspensions |
| title_sort | impact of microcapsules wettability on thermal conductivity of microencapsulated phase change material mpcm suspensions |
| topic | microencapsulated phase change material suspensions contact angle thermal conductivity maxwell formula correction factor |
| url | https://www.jstage.jst.go.jp/article/jtst/13/1/13_2018jtst0002/_pdf/-char/en |
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