scholarly journals Atomistic calculations of thermal conductivity in films made from graphene sheets for electron emitter applications

AIP Advances ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 105310
Author(s):  
S. N. Sami ◽  
R. Islam ◽  
R. P. Joshi
2015 ◽  
Vol 3 (9) ◽  
pp. 4884-4891 ◽  
Author(s):  
Wen Dai ◽  
Jinhong Yu ◽  
Yi Wang ◽  
Yingze Song ◽  
Fakhr E. Alam ◽  
...  

3DSG incorporated into a polyimide matrix greatly enhanced its thermal conductivity (up to 2.63 W m−1 K−1), approximately a 10-fold enhancement in comparison with that of neat polyimide.


2019 ◽  
Vol 814 ◽  
pp. 90-95 ◽  
Author(s):  
Guang Lei Lv ◽  
Yuan Yuan Li ◽  
Chen Fei ◽  
Zhi Hao Shan ◽  
Jing Gan ◽  
...  

Graphene nanosheets/polyurethane (GNS/PU) was prepared in situ by polymerization technique for the manufacture of PU safety shoes soles. The graphene nanosheets/polyurethane composites were characterized for their mechanical properties, thermal conductivity and abrasion resistance, and comparison is made with those of the neat polyurethane. The microstructural properties of GNS/PU were characterized by SEM. The results show that with the increase of the amount of graphene within the range of weight-percentages analyzed, the tensile strength of the composites gradually increases. The tensile strength of the GNS/PU composites increased to 64.14 MPa with 2 wt% GNS, compared with 55.1 MPa for neat PU. When the graphene sheets reached 2 wt%, the abrasion volume reached 71 mm3. Compared with the pure PU, the wear performance of GNS/PU composites was significantly improved.


RSC Advances ◽  
2015 ◽  
Vol 5 (53) ◽  
pp. 42492-42499 ◽  
Author(s):  
Jingying Cui ◽  
Shanming Li ◽  
Qing Hao ◽  
Huaizhou Zhao ◽  
Hongbo Zhao ◽  
...  

The incorporated graphene sheets acted as a growth template and result in dense texture with laminates, an increased Seebeck efficient, a decreased thermal conductivity, and therefore a 25%-enhanced-ZT in pressure direction.


2011 ◽  
Vol 22 (10) ◽  
pp. 105705 ◽  
Author(s):  
Ning Wei ◽  
Lanqing Xu ◽  
Hui-Qiong Wang ◽  
Jin-Cheng Zheng

Nanoscale ◽  
2014 ◽  
Vol 6 (6) ◽  
pp. 3344-3352 ◽  
Author(s):  
Bohayra Mortazavi ◽  
Markus Pötschke ◽  
Gianaurelio Cuniberti

We developed a multiscale approach to explore the effective thermal conductivity of polycrystalline graphene sheets.


2013 ◽  
Vol 55 (4) ◽  
pp. 889-894 ◽  
Author(s):  
A. A. Selezenev ◽  
A. Yu. Aleinikov ◽  
N. S. Ganchuk ◽  
S. N. Ganchuk ◽  
R. E. Jones ◽  
...  

Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1622 ◽  
Author(s):  
Jinhui Huang ◽  
Buning Zhang ◽  
Ming He ◽  
Xue Huang ◽  
Guoqiang Yin ◽  
...  

In this study, anisotropic graphene/graphene oxide (GO) aerogels (AGAs) were obtained by freeze-drying after direct participation of pristine graphene in the self-assembly of anisotropic gel by the heat flow method. After vacuum microwave treatment, the physical, chemical and structural characteristics of the AGAs were investigated. The results show that AGAs, in which the internal graphene sheets are parallel to the heat flow direction, are successfully prepared. After microwave treatment, the amount of oxygen and nitrogen reduces significantly and the sp2 domain increases. However, at the same time, many fragments and holes are generated in the graphene sheets. The effects of AGAs on the phase transition of paraffin is studied, and the results show that the melting enthalpy, solidification enthalpy and initial melting temperature of AGA/paraffin composites decreases as the GO content in the AGAs increases, whereas the melting range, solidifying range and subcooling degree increases. The highest axial thermal conductivity of the AGA/paraffin composite is 1.45 W/(mK), and the thermal conductivity enhancement efficiency is 884% (AGA content was 0.53 vol %). Compared with previously investigated, similar AGA/paraffin composites, the aerogels fabricated in this study have the obvious advantages of a simple fabrication process, a low cost and a high thermal conductivity enhancement efficiency. These aerogels possess the potential for application in phase-change energy storage (PES), thermal energy management and other fields.


Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3271
Author(s):  
Liang Zhang ◽  
Zhongke Shi ◽  
Buning Zhang ◽  
Jinhui Huang

Phased energy storage technologies are highly advantageous and feasible for storing and utilizing clean renewable energy resources, for instance, solar energy and waste heat, and it is an effective method to improve energy efficiency and save energy. However, phase change energy storage has some problems, for example, low thermal conductivity and phase change leakage, which lead to limited application. In this paper, anisotropic graphene aerogels were prepared by ice crystal template method with high thermal conductivity of graphene, and silver was attached to the pore wall graphene sheets and the graphene sheet boundaries of the aerogels. The results show that anisotropic graphene aerogels were successfully prepared, and SEM and EDS indicate that up to 9.14 at % silver was successfully attached to the graphene sheets and boundaries. The anisotropic thermal conductivity of the PArGO phase change composites after adsorption of the paraffin is significant, with a maximum axial thermal conductivity of PArGO of 1.20 W/(mK) and radial thermal conductivity of 0.54 W/(mK), compared to the pure paraffin (0.26 W/(mK)) increased by 362% and 108%, respectively. The enthalpy of the composite has been reduced to 149.6 J/g due to the silver particles attached, but the thermal properties have been greatly improved. In experiments simulating real temperature changes, PArGO achieves phase transitions very fast, with a 74% improvement on thermal efficiency of storage and discharge over the pure paraffin.


Sign in / Sign up

Export Citation Format

Share Document