title: Highly Stable and Conductive Microcapsules for Enhancement of Joule Heating Performance.
abstract: Nanocarbons show great promise for establishing the next generation of Joule heating systems, but suffer from the limited maximum temperature due to precociously convective heat dissipation from electrothermal system to surrounding environment. Here we introduce a strategy to eliminate such convective heat transfer by inserting highly stable and conductive microcapsules into the electrothermal structures. The microcapsule is composed of encapsulated long-chain alkanes and graphene oxide/carbon nanotube hybrids as core and shell material, respectively. Multiform carbon nanotubes in the microspheres stabilize the capsule shell to resist volume-change-induced rupture during repeated heating/cooling process, and meanwhile enhance the thermal conductance of encapsulated alkanes which facilitates an expeditious heat exchange. The resulting microcapsules can be homogeneously incorporated in the nanocarbon-based electrothermal structures. At a dopant of 5%, the working temperature can be enhanced by 30% even at a low voltage and moderate temperature, which indicates a great value in daily household applications. Therefore, the stable and conductive microcapsule may serve as a versatile and valuable dopant for varieties of heat generation systems.
authors.affiliation: Stephenson Institute for Renewable Energy and Department of Chemistry, University of Liverpool , Liverpool L69 7ZD, United Kingdom.
authors.forename: Zhaoliang
authors.initials: Z
authors.lastname: Zheng
authors.affiliation: Department of Electrical Engineering and Electronics, University of Liverpool , Liverpool L69 3GJ, United Kingdom.
authors.forename: Jidong
authors.initials: J
authors.lastname: Jin
authors.affiliation: International Center for Applied Mechanics, State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi'an Jiaotong University , Xi'an 710049, China.
authors.forename: Guang-Kui
authors.initials: GK
authors.lastname: Xu
authors.affiliation: Stephenson Institute for Renewable Energy and Department of Chemistry, University of Liverpool , Liverpool L69 7ZD, United Kingdom.
authors.forename: Jianli
authors.initials: J
authors.lastname: Zou
authors.affiliation: Stephenson Institute for Renewable Energy and Department of Chemistry, University of Liverpool , Liverpool L69 7ZD, United Kingdom.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Wais
authors.affiliation: EM Unit, Department of Cellular & Molecular Physiology, University of Liverpool , Liverpool L69 3BX, United Kingdom.
authors.forename: Alison
authors.initials: A
authors.lastname: Beckett
authors.affiliation: Nanoinvestigation Centre at Liverpool, University of Liverpool , Liverpool L69 3GL, United Kingdom.
authors.forename: Tobias
authors.initials: T
authors.lastname: Heil
authors.affiliation: Centre for Materials Discovery, University of Liverpool , Liverpool L69 7ZD, United Kingdom.
authors.forename: Sean
authors.initials: S
authors.lastname: Higgins
authors.affiliation: Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences , Fuzhou 350002, China.
authors.forename: Lunhui
authors.initials: L
authors.lastname: Guan
authors.affiliation: International Center for Applied Mechanics, State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi'an Jiaotong University , Xi'an 710049, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Stephenson Institute for Renewable Energy and Department of Chemistry, University of Liverpool , Liverpool L69 7ZD, United Kingdom.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Shchukin
keywords: carbon nanotube; electrothermal; emulsification; encapsulation; graphene oxide; microcapsule; nanocarbon hybrids; ultrasound