The correlation between electrical conductivity and second-order Raman modes of laser-reduced graphene oxide

2019 ◽  
Vol 21 (19) ◽  
pp. 10125-10134 ◽  
Author(s):  
Bing Ma ◽  
Raul D. Rodriguez ◽  
Alexey Ruban ◽  
Sergey Pavlov ◽  
Evgeniya Sheremet
Keyword(s):  
Electrical Conductivity ◽  
Atomic Force Microscopy ◽  
Graphene Oxide ◽  
Electrical Properties ◽  
Reduced Graphene Oxide ◽  
Second Order ◽  
Force Microscopy ◽  
Atomic Force ◽  
Reduced Graphene ◽  
Raman Modes

Second-order Raman modes correlate with the electrical properties of reduced graphene oxide measured at the nanoscale by atomic force microscopy.

scholarly journals Mechanical Characterization of Reduced Graphene Oxide Using AFM

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Alem Teklu ◽  
Canyon Barry ◽  
Matthew Palumbo ◽  
Collin Weiwadel ◽  
Narayanan Kuthirummal ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Graphene Oxide ◽  
Young’S Modulus ◽  
Reduced Graphene Oxide ◽  
Young's Modulus ◽  
Force Microscopy ◽  
Atomic Force ◽  
Reduction Cycle ◽  
Reduced Graphene ◽  
Oxide Sample

Nanoindentation coupled with Atomic Force Microscopy was used to study stiffness, hardness, and the reduced Young’s modulus of reduced graphene oxide. Oxygen reduction on the graphene oxide sample was performed via LightScribe DVD burner reduction, a cost-effective approach with potential for large scale graphene production. The reduction of oxygen in the graphene oxide sample was estimated to about 10 percent using FTIR spectroscopic analysis. Images of the various samples were captured after each reduction cycle using Atomic Force Microscopy. Elastic and spectroscopic analyses were performed on the samples after each oxygen reduction cycle in the LightScribe, thus allowing for a comparison of stiffness, hardness, and the reduced Young’s modulus based on the number of reduction cycles. The highest values obtained were after the fifth and final reduction cycle, yielding a stiffness of 22.4 N/m, a hardness of 0.55 GPa, and a reduced Young’s modulus of 1.62 GPa as compared to a stiffness of 22.8 N/m, a hardness of 0.58 GPa, and a reduced Young’s modulus of 1.84 GPa for a commercially purchased graphene film made by CVD. This data was then compared to the expected values of pristine single layer graphene. Furthermore, two RC circuits were built, one using a parallel plate capacitors made of light scribed graphene on a kapton substrate (LSGC) and a second one using a CVD deposited graphene on aluminum (CVDGC). Their RC time constants and surface charge densities were compared.

scholarly journals A Novel Inspection for Deformation Phenomenon of Reduced-graphene Oxide via Quantitative Nano-mechanical Atomic Force Microscopy

2012 ◽  
Vol 36 ◽  
pp. 571-577 ◽  
Author(s):  
Jen-You Chu ◽  
Wei-Sheng Hsu ◽  
Wei-Ren Liu ◽  
Hung-Min Lin ◽  
Hsin-Ming Cheng ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Force Microscopy ◽  
Atomic Force ◽  
Reduced Graphene

Dielectrophoretic assembly and atomic force microscopy modification of reduced graphene oxide

2011 ◽  
Vol 110 (11) ◽  
pp. 114515 ◽  
Author(s):  
Yu Zhang ◽  
Lianqing Liu ◽  
Ning Xi ◽  
Yuechao Wang ◽  
Zaili Dong ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Force Microscopy ◽  
Atomic Force ◽  
Reduced Graphene

Preparation and properties of chemically reduced graphene oxide/copolymer-polyamide nanocomposites

e-Polymers ◽  
2017 ◽  
Vol 17 (1) ◽  
pp. 3-14 ◽  
Author(s):  
Xin Liu ◽  
Xiao Yu Shao ◽  
Guan Biao Fang ◽  
Hai Feng He ◽  
Zhen Gao Wan
Keyword(s):  
Electrical Conductivity ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Reduced Graphene ◽  
Chemically Reduced Graphene Oxide

AbstractTo enhance the physical properties of copolymer-polyamide (CO-PA), a sequence of nanocomposites based upon CO-PA and chemically reduced graphene oxide (CRGO) nanoplatelets were prepared by in-situ reduction using hydrazine hydrate. Graphene oxide (GO), prepared by the improved Hummers method, was used to fabricate CRGO nanaoplatelets. Atomic-force microscopy (AFM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) analysis showed that the thickness and the width of GO was about 0.9 nm and 1 μm, respectively. An abundance of oxygen-containing functional groups were introduced onto the GO sheets. XRD and SEM analysis showed that CRGO nanoplatelets were well dispersed in the CO-PA matrix with the appropriate CRGO content. TGA and DSC analysis demonstrated that CRGO nanoplatelets can significantly improve the thermal stability, glass-transition temperature, crystallization temperature of the composites. The mechanical properties of the nanocomposites were improved significantly with the appropriate increment of CRGO nanoplatelets content, though the elongation at break of the composites decreased with the increase of CRGO nanoplatelets content. The electrical conductivity test showed a significant increase in electrical conductivity from an insulator to almost a semiconductor with increasing CRGO nanoplatelets content. And at 1.0 wt% CRGO content, the electrical percolation threshold of the nanocomposites was found.

scholarly journals Measurements of the Electrical Conductivity of Monolayer Graphene Flakes Using Conductive Atomic Force Microscopy

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2575
Author(s):  
Soomook Lim ◽  
Hyunsoo Park ◽  
Go Yamamoto ◽  
Changgu Lee ◽  
Ji Won Suk
Keyword(s):  
Electrical Conductivity ◽  
Atomic Force Microscopy ◽  
Graphene Oxide ◽  
Monolayer Graphene ◽  
Synthesis Methods ◽  
Clear Understanding ◽  
Conductive Atomic Force Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Graphene Flakes

The intrinsic electrical conductivity of graphene is one of the key factors affecting the electrical conductance of its assemblies, such as papers, films, powders, and composites. Here, the local electrical conductivity of the individual graphene flakes was investigated using conductive atomic force microscopy (C-AFM). An isolated graphene flake connected to a pre-fabricated electrode was scanned using an electrically biased tip, which generated a current map over the flake area. The current change as a function of the distance between the tip and the electrode was analyzed analytically to estimate the contact resistance as well as the local conductivity of the flake. This method was applied to characterize graphene materials obtained using two representative large-scale synthesis methods. Monolayer graphene flakes synthesized by chemical vapor deposition on copper exhibited an electrical conductivity of 1.46 ± 0.82 × 106 S/m. Reduced graphene oxide (rGO) flakes obtained by thermal annealing of graphene oxide at 300 and 600 °C exhibited electrical conductivities of 2.3 ± 1.0 and 14.6 ± 5.5 S/m, respectively, showing the effect of thermal reduction on the electrical conductivity of rGO flakes. This study demonstrates an alternative method to characterizing the intrinsic electrical conductivity of graphene-based materials, which affords a clear understanding of the local properties of individual graphene flakes.

scholarly journals Effect of reduced graphene oxide (rGO) compaction degree and concentration on rGO-polymer composites printability and cell interactions

2021 ◽  
Author(s):  
Maria Camara Torres ◽  
Ravi Sinha ◽  
Siamak Eqtesadi ◽  
Rune Wendelbo ◽  
Marco Scatto ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Graphene Oxide ◽  
Electrical Properties ◽  
Bulk Density ◽  
Polymer Composites ◽  
Reduced Graphene Oxide ◽  
Volume Fraction ◽  
Scale Production ◽  
Melt Compounding ◽  
Reduced Graphene

Graphene derivatives combined with polymers have attracted enormous attention for bone tissue engineering applications. Among others, reduced graphene oxide (rGO) is one of the preferred graphene-based fillers for the preparation of composites via melt compounding, and their further processing into 3D scaffolds, due to its established large-scale production method, thermal stability, and electrical conductivity. In this study, rGO (low bulk density 10g/L) was compacted by densification using a solvent (either acetone or water) prior to melt compounding, to simplify its handling and dosing into a twin-screw extrusion system. The effects of rGO bulk density (medium and high), densification solvent, and rGO concentration (3, 10 and 15% in weight) on rGO dispersion within the composite, electrical conductivity, printability and cell-material interactions were studied. High bulk density rGO (90 g/L) occupied a low volume fraction within polymer composites, offering poor electrical properties but a reproducible printability up to 15 wt% rGO. On the other hand, the volume fraction within the composites of medium bulk density rGO (50 g/L) was higher for a given concentration, enhancing rGO particle interactions and leading to enhanced electrical conductivity, but compromising the printability window. For a given bulk density (50 g/L), rGO densified in water was more compacted and offered poorer dispersability within the polymer than rGO densified in acetone, and resulted in scaffolds with poor layer bonding or even lack of printability at high rGO percentages. A balance in printability and electrical properties was obtained for composites with medium bulk density rGO densified in acetone. Here, increasing rGO concentration led to more hydrophilic composites with a noticeable increase in protein adsorption. Moreover, scaffolds prepared with such composites presented antimicrobial properties even at low rGO contents (3 wt%). In addition, the viability and proliferation of human mesenchymal stromal cells (hMSCs) was maintained on scaffolds with up to 15% rGO and with enhanced osteogenic differentiation on 3% rGO scaffolds.

scholarly journals Electrical conductivity of silver nanoparticle doped carbon nanofibres measured by CS-AFM

RSC Advances ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 4553-4562 ◽  
Author(s):  
Wael Ali ◽  
Valbone Shabani ◽  
Matthias Linke ◽  
Sezin Sayin ◽  
Beate Gebert ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Atomic Force Microscopy ◽  
Electrical Properties ◽  
Silver Nanoparticle ◽  
Carbon Nanofibres ◽  
Force Microscopy ◽  
Atomic Force ◽  
Composite Carbon

In this work, a pioneering study on the electrical properties of composite carbon nanofibres (CNFs) using current-sensitive atomic force microscopy (CS-AFM) has been demonstrated.

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