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Nano Research 2019, 12(10): 2498-2508 https://doi.org/10.1007/s12274-019-2476-7
Research Article | Issue | Published: 08 August 2019

Assembly of carbon nanodots in graphene-based composite for flexible electro-thermal heater with ultrahigh efficiency

Show Author's Information Xin Meng1,  Tianxing Chen1,  Yao Li1,  Siyuan Liu1,  Hui Pan1,  Yuning Ma2( ),  Zhixin Chen3,  Yanping Zhang4,  Shenmin Zhu1( )
State Key Laboratory of Metal Matrix Composites,School of Material Science and Engineering, Shanghai Jiao Tong University,Shanghai,200240,China;
School of Environmental Science and Engineering,Shanghai Jiao Tong University,Shanghai,200240,China;
School of Mechanical, Materials&Mechatronics Engineering,University of Wollongong,Wollongong, NSW,2522,Australia;
Shanghai LEVSON Group Co.,Ltd.,Shanghai,200444,China;
Keywords:
graphene film, carbon nanodots, self-assembly, electro-thermal heater, three-dimensional (3D) conductive framework
Topics:
GrapheneLiquid crystals NanocrystalsNanodots NanorodsSelf assembly
Cite this article:
Meng X, Chen T, Li Y, et al. Assembly of carbon nanodots in graphene-based composite for flexible electro-thermal heater with ultrahigh efficiency. Nano Research, 2019, 12(10): 2498-2508. https://doi.org/10.1007/s12274-019-2476-7
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Abstract Full text Electronic supplementary material About this article

A high-efficiency electro-thermal heater requires simultaneously high electrical and thermal conductivities to generate and dissipate Joule heat efficiently. A low input voltage is essential to ensure the heater's safe applications. However, the low voltage generally leads to low saturated temperature and heating rate and hence a low thermal efficiency. How to reduce the input voltage while maintaining a high electro-thermal efficiency is still a challenge. Herein, a highly electrical and thermal conductive film was constructed using a graphene-based composite which has an internal three-dimensional (3D) conductive network. In the 3D framework, cellulose nanocrystalline (CNC) phase with chiral liquid crystal manner presents in the form of aligned helix between the graphene oxide (GO) layers. Carbon nanodots (CDs) are assembled inside the composite as conductive nanofillers. Subsequent annealing and compression results in the formation of the assembled GO-CNC-CDs film. The carbonized CNC nanorods (CNR) with the helical alignment act as in-plane and through-plane connections of neighboring reduced GO (rGO) nanosheets, forming a conductive network in the composite film. The CDs with ultrafast electrons transfer rates provide additional electrons and phonons transport paths for the composite. As a result, the obtained graphene-based composite film (rGO-CNR-CDs) exhibited a high thermal conductivity of 1, 978.6 W·m-1·K-1 and electrical conductivity of 2, 053.4 S·cm-1, respectively. The composite film showed an outstanding electro-thermal heating efficiency with the saturated temperature of 315 ℃ and maximum heating rate of 44.9 ℃·s-1 at a very low input voltage of 10 V. The freestanding graphene composite film with the delicate nanostructure design has a great potential to be integrated into electro-thermal devices.


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Electronic supplementary material
About this article

Assembly of carbon nanodots in graphene-based composite for flexible electro-thermal heater with ultrahigh efficiency

Show Author's information Xin Meng1, Tianxing Chen1, Yao Li1, Siyuan Liu1, Hui Pan1, Yuning Ma2( ), Zhixin Chen3, Yanping Zhang4, Shenmin Zhu1( )
State Key Laboratory of Metal Matrix Composites,School of Material Science and Engineering, Shanghai Jiao Tong University,Shanghai,200240,China;
School of Environmental Science and Engineering,Shanghai Jiao Tong University,Shanghai,200240,China;
School of Mechanical, Materials&Mechatronics Engineering,University of Wollongong,Wollongong, NSW,2522,Australia;
Shanghai LEVSON Group Co.,Ltd.,Shanghai,200444,China;

Abstract

A high-efficiency electro-thermal heater requires simultaneously high electrical and thermal conductivities to generate and dissipate Joule heat efficiently. A low input voltage is essential to ensure the heater's safe applications. However, the low voltage generally leads to low saturated temperature and heating rate and hence a low thermal efficiency. How to reduce the input voltage while maintaining a high electro-thermal efficiency is still a challenge. Herein, a highly electrical and thermal conductive film was constructed using a graphene-based composite which has an internal three-dimensional (3D) conductive network. In the 3D framework, cellulose nanocrystalline (CNC) phase with chiral liquid crystal manner presents in the form of aligned helix between the graphene oxide (GO) layers. Carbon nanodots (CDs) are assembled inside the composite as conductive nanofillers. Subsequent annealing and compression results in the formation of the assembled GO-CNC-CDs film. The carbonized CNC nanorods (CNR) with the helical alignment act as in-plane and through-plane connections of neighboring reduced GO (rGO) nanosheets, forming a conductive network in the composite film. The CDs with ultrafast electrons transfer rates provide additional electrons and phonons transport paths for the composite. As a result, the obtained graphene-based composite film (rGO-CNR-CDs) exhibited a high thermal conductivity of 1, 978.6 W·m-1·K-1 and electrical conductivity of 2, 053.4 S·cm-1, respectively. The composite film showed an outstanding electro-thermal heating efficiency with the saturated temperature of 315 ℃ and maximum heating rate of 44.9 ℃·s-1 at a very low input voltage of 10 V. The freestanding graphene composite film with the delicate nanostructure design has a great potential to be integrated into electro-thermal devices.

Keywords: graphene film, carbon nanodots, self-assembly, electro-thermal heater, three-dimensional (3D) conductive framework

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Publication history
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Acknowledgements

Publication history

Received: 29 March 2019
Revised: 05 June 2019
Accepted: 12 July 2019
Published: 08 August 2019
Issue date: October 2019

Copyright

© Tsinghua University Press and Springer-Verlag GmbH Germany, part of Springer Nature 2019

Acknowledgements

Acknowledgements

This work was supported by the National Key R&D Program of China (Nos. 2016YFA0202900 and 2016YFC1402400), National Natural Science Foundation of China (No. 51672173), Shanghai Science and Technology committee (No. 17JC1400700 and 18520744700), Science and Technology Planning Project of Guangdong Province (No. 2016A010103018). The authors gratefully acknowledge the Shanghai Synchrotron Radiation Facility (SSRF) and Shanghai LEVSON Group Co., Ltd. for the measurements.

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