HRTEM Observation of Mechanically Exfoliated Graphene from Natural Graphite and HOPG

2019 ◽  
Vol 19 (5) ◽  
pp. 81-85 ◽  
Author(s):  
SeongYong Park ◽  
YoungJoon Suh ◽  
Herman Floresca ◽  
Moon Kim
2020 ◽  
Vol 140 (2) ◽  
pp. 117-127
Author(s):  
Yuki Amada ◽  
Takahiro Ueno ◽  
Koichiro Sawa ◽  
Noboru Morita ◽  
Kazuhiko Takahashi

2021 ◽  
Author(s):  
Joong Tark Han ◽  
Joon Young Cho ◽  
Jeong Hoon Kim

The thermal stability of solution-exfoliated graphene oxide (GO) in air is one of the most important physical properties influencing its potential applications. To date, majority of the GO prepared by...


2021 ◽  
Vol 287 ◽  
pp. 129263
Author(s):  
Siva Sankar Nemala ◽  
Sujitha Ravulapalli ◽  
Purnendu Kartikay ◽  
Ramu Banavath ◽  
Sudhanshu Mallick ◽  
...  

2021 ◽  
Vol 173 ◽  
pp. 105732
Author(s):  
Xue Rui ◽  
Yong Geng ◽  
Xin Sun ◽  
Han Hao ◽  
Shijiang Xiao

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 607
Author(s):  
Carolina Hermida-Merino ◽  
Fernando Pardo ◽  
Gabriel Zarca ◽  
João M. M. Araújo ◽  
Ane Urtiaga ◽  
...  

In this work, polymeric membranes functionalized with ionic liquids (ILs) and exfoliated graphene nanoplatelets (xGnP) were developed and characterized. These membranes based on graphene ionanofluids (IoNFs) are promising materials for gas separation. The stability of the selected IoNFs in the polymer membranes was determined by thermogravimetric analysis (TGA). The morphology of membranes was characterized using scanning electron microscope (SEM) and interferometric optical profilometry (WLOP). SEM results evidence that upon the small addition of xGnP into the IL-dominated environment, the interaction between IL and xGnP facilitates the migration of xGnP to the surface, while suppressing the interaction between IL and Pebax®1657. Fourier transform infrared spectroscopy (FTIR) was also used to determine the polymer–IoNF interactions and the distribution of the IL in the polymer matrix. Finally, the thermodynamic properties and phase transitions (polymer–IoNF) of these functionalized membranes were studied using differential scanning calorimetry (DSC). This analysis showed a gradual decrease in the melting point of the polyamide (PA6) blocks with a decrease in the corresponding melting enthalpy and a complete disappearance of the crystallinity of the polyether (PEO) phase with increasing IL content. This evidences the high compatibility and good mixing of the polymer and the IoNF.


Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1946 ◽  
Author(s):  
Hae-Jun Kwon ◽  
Sang-Wook Woo ◽  
Yong-Ju Lee ◽  
Je-Young Kim ◽  
Sung-Man Lee

The electrochemical performance of modified natural graphite (MNG) and artificial graphite (AG) was investigated as a function of electrode density ranging from 1.55 to 1.7 g∙cm−3. The best performance was obtained at 1.55 g∙cm−3 and 1.60 g∙cm−3 for the AG and MNG electrodes, respectively. Both AG, at a density of 1.55 g∙cm−3, and MNG, at a density of 1.60 g∙cm−3, showed quite similar performance with regard to cycling stability and coulombic efficiency during cycling at 30 and 45 °C, while the MNG electrodes at a density of 1.60 g∙cm−3 and 1.7 g∙cm−3 showed better rate performance than the AG electrodes at a density of 1.55 g∙cm−3. The superior rate capability of MNG electrodes can be explained by the following effects: first, their spherical morphology and higher electrode density led to enhanced electrical conductivity. Second, for the MNG sample, favorable electrode tortuosity was retained and thus Li+ transport in the electrode pore was not significantly affected, even at high electrode densities of 1.60 g∙cm−3 and 1.7 g∙cm−3. MNG electrodes also exhibited a similar electrochemical swelling behavior to the AG electrodes.


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