JOURNAL OF MATERIALS SCIENCE
·
2015
·Vol. 51
·期 2
·1043-1051
·
IF 2.371
Li Chang,Xu Yi-Tao,Zhao Bo,Jiang Li,Chen Shi-Guo,Xu Jian-Bin,Fu Xian-Zhu,Sun Rong,Wong Ching-Ping
Graphene nanosheets are facilely prepared by electrochemical exfoliation of graphite in sodium tungstate aqueous solution. Through a filtration-transfer procedure and followed by heat treatment, the graphene nanosheets are deposited on the polyethylene terephthalate substrate to form electrothermal films. The graphene electrothermal films exhibit low square resistance of 159 Ω/sq, high in-plane thermal conductivity of 658 W/m/K, and excellent heat propagation with uniform temperature distribution. The steady-state temperature of the films increases from 32 to 139 °C as the applied voltage increases from 5 to 30 V. The electrothermal response of the graphene films is as fast as <20 s. The graphene film heaters also display good flexibility. Even after bending 100 times, the graphene film heaters still exhibit almost the same electrothermal performance.
研究领域:
材料科学
·
热能工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2020
·
IF 7.489
Te Hu,Huijian Ye,Zhenggang Luo,Junjie Ma,Boyuan Zhang,Xuanhe Zhang,Jinwei Song,Qingping Wang,Lixin Xu
The use of stabilizer with designer structures can effectively promote graphite exfoliation in common solvents to render functionalized graphene desirable for their various applications. Herein, a hyperbranched polyethylene copolymer , HBPE@Py@Acryl, simultaneously bearing multiple pyrene terminal groups and pendant acryloyl moieties has been successfully synthesized from ethylene with a Pd-diimine catalyst based on unique chain walking mechanism. The unique structural design of the HBPE@Py@Acryl makes it capable of effectively promote graphite exfoliation in a series of common, low-boiling-point organic solvents , e.g. CHCl 3 , to render stable graphene dispersions with concentrations effectively adjustable by changing feed concentrations of graphite and polymer or sonication time. Meanwhile, it can be irreversibly adsorbed on the exfoliated graphene surface based on the π-π interactions between them to concurrently render acryloyl-functionalized graphene free of structural defects, with majority (92.7%) of them having a thickness of 2–3 layers. This allows us to obtain graphene electrothermal films simply by filtration and UV irradiation, which exhibit outstanding stability in use. The action mechanism of the HBPE@Py@Acryl as stabilizer for promoting graphite exfoliation and the role of UV irradiation on improving the stability in use of resulting graphene films have been elucidated.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Materials Today Communications
·
2025
·
IF 4.5
Chunmei Yang,Siman Zhou,Bo Guan,Xiaoyu Feng,Xu Tang,Jipeng Ge,Chengwen Sun,Mengjiao Shi,Wen Qu
The application of new functional materials such as graphene in the field of wearable devices has become a new trend in the future development of intelligent electronic products. In response to the insufficient flexibility of graphene based electrothermal films, this article uses Tempo-oxidized cellulose nanofibrils (CNF) rich in carboxylic acid groups to improve them. In order to prepare this graphene-CNF composite electrothermal film, ultrasonic technology was used to mix graphene with CNF, and then the film was extracted from the mixed suspension by vacuum filtration method. On this basis, further comparison and analysis of the electrothermal and mechanical properties of the film with different graphene contents are conducted. The research results indicate that the addition of CNF to the film establishes a strong interfacial bond, effectively improving the flexibility of the film. In addition, the composite electrothermal film containing 50 wt% graphene can be heated to 37 °C with only 3 V and can maintain long-term stability. The graphene-CNF composite electrothermal film prepared in this study does not require a substrate, meeting the dual requirements of flexibility and maintaining comfortable body temperature, which demonstrates a broad application prospect.
研究领域:
材料科学
·
智能电子
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Surfaces and Interfaces
·
2022
·
IF 6.137
Xiang-Le Liu,Min Li,Wen-Hao Geng,Weiwei Cao,Yun-Hua Tian,Tong-Yu Li,Peng-Shuai Bin,Peng-Fei Qian,Hong-Zhang Geng
Carbon nanomaterials are ideal materials for electrothermal applications because of their superior thermal conductivity, electrical conductivity, and mechanical properties. Electrothermal composites with excellent performance should have the characteristics of rapid temperature response, uniform heating temperature distribution, and good thermal stability after prolonged heating. However, for previously prepared electrothermal composites still have some shortcomings such as long temperature response time, uneven temperature distribution and poor thermal stability after long time heating. In this study, the composite electrothermal films with excellent performances were obtained by a layer-by-layer deposition approach, which were synthesized by pouring epigallocatechin gallate-functionalized multi-walled carbon nanotubes (E-MWCNTs) into a polytetrafluoroethylene mold and subsequently curing the polyvinyl alcohol (PVA) solution on the CNT layer. The electro-heating behavior of composite electrothermal film with different content and size was investigated by applying various voltages. They exhibit excellent electrothermal property, that is, a rapid temperature response, which can reach the steady-state temperature ( T MAX ) within 90 s. In addition, the maximum temperature can reach about 140 °C at 12 V. It was observed that the temperature of the composite electrothermal film has no significant change during the cycle tests of various voltages and 5 h aging time. According to the results of the experiment, the electrothermal properties of the composite electrothermal films are affected by the content of multi-walled carbon nanotubes (MWCNTs) and the applied voltage, which means that we can achieve accurate control of its properties by adjusting the content of MWCNTs and the applied voltage. Moreover, we have great expectations that these composite electrothermal films will have broad prospects for thermal management in wearable applications and electro-devices.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
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