Unique synergistic effects of graphene oxide and carbon nanotube hybrids on the tribological properties of polyimide nanocomposites

2018 ◽  
Vol 117 ◽  
pp. 217-224 ◽  
Author(s):  
Chunying Min ◽  
Dengdeng Liu ◽  
Chen Shen ◽  
Qiaqia Zhang ◽  
Haojie Song ◽  
...  
2016 ◽  
Vol 24 (3) ◽  
pp. 291-305 ◽  
Author(s):  
Zihao Xu ◽  
Chun Wei ◽  
Yongyang Gong ◽  
Zirun Chen ◽  
Dejiang Yang ◽  
...  

Author(s):  
Arukali Sammaiah ◽  
Qingwen Dai ◽  
Wei Huang ◽  
Xiaolei Wang

As a thin material with a lamellar structure, graphene oxide (GO) may extend the already superior tribological properties of ferrofluids. For this purpose, magnetic Fe3O4 nanoparticles were fabricated on the GO surface with different compositions by the co-precipitation method. Then, the GO-Fe3O4 nanohybrids coated with a surfactant were dispersed in paraffin oil to achieve stable ferrofluids. The tribological results demonstrated that compared with paraffin oil, friction coefficient reduced by 19.4% and 25.8–35.5% when lubricated with ferrofluids containing 0.5 wt% of Fe3O4 nanoparticle and GO-Fe3O4 nanohybrids, respectively. The results also indicated that nanohybrids with the higher content of GO exhibited better lubrication behaviors. It can be concluded that the introduction of GO helps to further promote the lubricity of traditional Fe3O4-based ferrofluids. The excellent tribological behaviors of GO-Fe3O4-based ferrofluids were ascribed to the triboflim and the synergistic effects of GO and Fe3O4.


2021 ◽  
Vol 154 ◽  
pp. 106726
Author(s):  
Saisai Huang ◽  
Bingli Pan ◽  
Mengxin Xie ◽  
Jiayu Gao ◽  
Guangming Zhao ◽  
...  

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Bo Chen ◽  
Shenghu Liang ◽  
Song Lu ◽  
Kun Zou ◽  
Yitian Peng ◽  
...  

Chromium (Cr)-based coatings have been widely used to strengthen the friction reduction and wear resistance on various kinds of surface. Here, the stable aqueous dispersion of oxidized multi-walled carbon nanotube (MWCNT) and graphene oxide nanosheets (GOS) was obtained by ultrasonic oxidation treatment. Then, MWCNT-Cr and GOS-Cr composite coatings were prepared using the direct current electrochemical co-deposition process on 420 stainless steel in the electrolyte with the addition of MWCNT and GOS under different current density and temperature. The morphology, structure, hardness and tribological properties of MWCNT-Cr and GOS-Cr composite coating are comparatively studied using pure Cr coating as a baseline. The friction reduction performance of MWCNT-Cr and GOS-Cr composite coatings was improved at optimum current density and temperature. The anti-wear properties of MWCNT-Cr and GOS-Cr composite coatings were enhanced by uniform embedment of MWCNT and GOS in coatings increasing the hardness and lubricity. This study suggests that the introduction of oxidized MWCNT and GOS with good dispersion could enhance the wear resistance and friction reduction of pure Cr coating due to their excellent dispersion, mechanical, and lubricant properties.


Author(s):  
Rouwei Yan ◽  
Biao Xu ◽  
K. P. Annamalai ◽  
Tianlu Chen ◽  
Zhiming Nie ◽  
...  

Background : Renewable energies are in great demand because of the shortage of traditional fossil energy and the associated environmental problems. Ni and Se-based materials are recently studied for energy storage and conversion owing to their reasonable conductivities and enriched redox activities as well as abundance. However, their electrochemical performance is still unsatisfactory for practical applications. Objective: To enhance the capacitance storage of Ni-Se materials via modification of their physiochemical properties with Fe. Methods: A two-step method was carried out to prepare FeNi-Se loaded reduced graphene oxide (FeNi-Se/rGO). In the first step, metal salts and graphene oxide (GO) were mixed under basic condition and autoclaved to obtain hydroxide intermediates. As a second step, selenization process was carried out to acquire FeNi-Se/rGO composites. Results: X-ray diffraction measurements (XRD), nitrogen adsorption at 77K, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were carried out to study the structures, porosities and the morphologies of the composites. Electrochemical measurements revealed that FeNi-Se/rGO notably enhanced capacitance than the NiSe/G composite. This enhanced performance was mainly attributed to the positive synergistic effects of Fe and Ni in the composites, which not only had influence on the conductivity of the composite but also enhanced redox reactions at different current densities. Conclusion: NiFe-Se/rGO nanocomposites were synthesized in a facile way. The samples were characterized physicochemically and electrochemically. NiFeSe/rGO giving much higher capacitance storage than the NiSe/rGO explained that the nanocomposites could be an electrode material for energy storage device applications.


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