scholarly journals Testing Graphene Films Produced Through Electrochemical Exfoliation Using Sulfate Electrolytes

2021 ◽  
Vol 10 (4) ◽  
Author(s):  
Samuel Blankenship ◽  
Stefanie Davis ◽  
Mangilal Agarwal
Keyword(s):  
Electrolyte Solution ◽  
Efficient Method ◽  
Electrical Resistance ◽  
Composite Films ◽  
Electrochemical Exfoliation ◽  
Graphene Films ◽  
Sulphate Electrolyte ◽  
Resultant Data ◽  
Graphene Flakes ◽  
Post Hoc

Graphene is one of the most commonly researched materials in nanoscience and finding a cheap and efficient method to manufacture it is highly desirable because of its incredible properties. Electrochemical exfoliation involves splitting graphite into graphene by soaking the foil in an electrolyte solution and then providing an electric current. This paper evaluates the extent to which the sulphate electrolyte used in the electrochemical exfoliation process affects the electrical resistance of films created using flakes generated from the reaction. Using the method and conducting an ANOVA test with Tukey HSD Post-Hoc test on the resultant data provides significant and varied results when concerning the electrolyte variety. This implies that changing the quality and speed of the electrolyte reaction has a definitive effect on the resistance of composite films created out of graphene flakes produced from the reaction.

scholarly journals Electrical behavior of graphene under temperature effect and survey of I–T curve

2019 ◽  
Vol 13 (4) ◽  
pp. 351-356
Author(s):  
M. Haditale ◽  
R. S. Dariani ◽  
E. Ghasemian Lemraski
Keyword(s):  
Temperature Effect ◽  
Effect Of Temperature ◽  
Electrical Behavior ◽  
Electrochemical Exfoliation ◽  
Ohmic Behavior ◽  
Graphene Flakes ◽  
Spray Volume

Abstract Graphene flakes were made from electrochemical exfoliation. To study graphene planes, different volumes of graphene solutions (1, 2, 4, and 7 ml) were sprayed on glass lamellae to get different graphene planes. I–V curve of all samples shows ohmic behavior with resistance in the order of kΩ which increases the slope of the I–V curve with increasing graphene planes (spray volume). The effect of temperature on all samples shows a clear jump in I–T curves. It is found that up to 150 °C current is almost constant, but after that current increases highly in the range of 1.8–10 times and resistance reduces sharply. Also, samples with lower graphene planes affected highly with temperature effect.

Modified graphene/polyimide composite films with strongly enhanced thermal conductivity

Nanoscale ◽  
2019 ◽  
Vol 11 (17) ◽  
pp. 8219-8225 ◽  
Author(s):  
Xian Wu ◽  
Haoliang Li ◽  
Kui Cheng ◽  
Hanxun Qiu ◽  
Junhe Yang
Keyword(s):  
Thermal Conductivity ◽  
Thermal Management ◽  
Composite Films ◽  
Highly Efficient ◽  
Graphene Films ◽  
Modified Graphene ◽  
Enhanced Thermal Conductivity

An effective “modified-welding” approach to prepare graphene films with excellent thermal conductivity and flexibility for highly efficient thermal management.

scholarly journals Mechanical and Electroconductive Properties of Mono- and Bilayer Graphene–Carbon Nanotube Films

Coatings ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 74 ◽  
Author(s):  
Michael Slepchenkov ◽  
Olga Glukhova
Keyword(s):  
Carbon Nanotube ◽  
Composite Film ◽  
Electrical Resistance ◽  
Composite Films ◽  
Bilayer Film ◽  
Vertical Force ◽  
Covalent Bonds ◽  
Local Stresses ◽  
Axial Stretching ◽  
Tube Distance

This article presents the results of a computer study of electrical conductivity and deformation behavior of new graphene–carbon nanotube (CNT) composite films under bending and stretching. Mono- and bilayer hybrid structures with CNTs (10,0) and (12,0) and an inter-tube distance of 10 and 12 hexagons were considered. It is revealed that elastic deformation is characteristic for mono- and bilayer composite films both in bending and stretching. It is found that, in the case of bending in a direction perpendicular to CNTs, the composite film takes the form of an arc, and, in the case of bending in a direction along CNTs, the composite film exhibits behavior that is characteristic of a beam subjected to bending deformation as a result of exposure to vertical force at its free end. It is shown that mono- and bilayer composite films are more resistant to axial stretching in the direction perpendicular to CNTs. The bilayer composite films with an inter-tube distance of 12 hexagons demonstrate the greatest resistance to stretching in a direction perpendicular to CNTs. It is established that the CNT diameter and the inter-tube distance significantly affect the strength limits of composite films under axial stretching in a direction along CNTs. The composite films with CNT (10,0) and an inter-tube distance of 12 hexagons exhibit the highest resistance to stretching in a direction along CNTs. The calculated distribution of local stresses of the atomic network of deformed mono- and bilayer composite films showed that the maximum stresses fall on atoms forming covalent bonds between graphene and CNT, regardless of the CNT diameter and inter-tube distance. The destruction of covalent bonds occurs at the stress of ~1.8 GPa. It is revealed that the electrical resistance of mono- and bilayer composite films decreases with increasing bending. At the same time, the electrical resistance of a bilayer film is 1.5–2 times less than that of a monolayer film. The lowest electrical resistance is observed for composite films with a CNT (12,0) of metallic conductivity.

Facile electrochemical assisted synthesis of ZnO/graphene nanosheets with enhanced photocatalytic activity

RSC Advances ◽  
2015 ◽  
Vol 5 (118) ◽  
pp. 97788-97797 ◽  
Author(s):  
Sandesh Y. Sawant ◽  
Moo Hwan Cho
Keyword(s):  
Zinc Oxide ◽  
Photocatalytic Activity ◽  
Electrolyte Solution ◽  
Graphene Nanosheets ◽  
Zinc Nitrate ◽  
Electrochemical Exfoliation

In the present study, an electrochemical exfoliation technique was used to synthesize a series of zinc oxide/graphene (ZnO/Gr) nanocomposites using different concentrations of zinc nitrate in an electrolyte solution.

Capacitance of graphene films: effect of the number of layers of the constituent graphene flakes

2019 ◽  
Vol 23 (8) ◽  
pp. 2281-2290 ◽  
Author(s):  
Afkham Mir ◽  
G. N. Abhilesh ◽  
Rupesh M. Tamgadge ◽  
Anupam Shukla
Keyword(s):  
Graphene Films ◽  
Number Of Layers ◽  
Graphene Flakes

Fabrication of Carbon Nanotube/Low Density Polyethylene Composites for Strain Sensing

2011 ◽  
Vol 495 ◽  
pp. 33-36
Author(s):  
Radwa R. Abdel Chafy ◽  
Mustafa H. Arafa ◽  
Amal M. K. Esawi
Keyword(s):  
Electrical Resistance ◽  
Composite Films ◽  
Load Condition ◽  
Strain Range ◽  
Low Density Polyethylene ◽  
Gauge Factor ◽  
Low Density ◽  
Strain Sensing ◽  
Percolation Behavior ◽  
Measured Resistance

Carbon Nanotubes (CNTs) have shown remarkable electrical, piezoresistive properties as well as other physical properties. The aim of this study is to investigate the potential of CNT-polymer composites in strain sensing using low density polyethylene (LDPE) polymer. Different CNT loadings were used (0, 1, 2, 3.5, 5, 6.5 and 8 weight %). CNT/LDPE composite films of 1mm thickness were fabricated using compression molding. The electrical resistance at no load condition was measured and the percolation behavior was obtained. The percolation threshold was found to be in the range of (2-5) wt%, where a decrease in resistivity by 5 orders of magnitude was observed. The sensitivity (gauge factor – GF) of the films was evaluated by correlating the strain applied with the simultaneously measured resistance. For a strain range of up to 320 µε, a gauge factor of 200 was achieved at a CNT loading of 5 wt%.

scholarly journals UV-VISIBLE OPTICAL ABSORBANCE OF GRAPHENE OXIDE IN COPPER IONIC LIQUID SYNTHESIZED VIA ELECTROCHEMICAL METHOD ASSISTED BY A COPPER COIL

2018 ◽  
Vol 3 (2) ◽  
pp. 85-92
Author(s):  
Wipsar Sunu Brams Dwandaru ◽  
Oktiana Lusi Priyani ◽  
Bagas Prakoso ◽  
Rhyko Irawan Wisnuwijaya ◽  
Iman Santoso
Keyword(s):  
Ionic Liquid ◽  
Graphene Oxide ◽  
Electrolyte Solution ◽  
Blue Shift ◽  
Electrolyte Solutions ◽  
Electrical Circuit ◽  
Electrochemical Exfoliation ◽  
Optical Absorbance ◽  
Uv Visible ◽  
Copper Coil

An optical absorbance study using Ultraviolet-Visible (UV-Vis) spectrophotometer device has been conducted on graphene oxide (GO) in copper (Cu) ionic liquid using electrochemical exfoliation combined with a direct current (DC) electrical circuit of copper coil given inside the electrolyte solution. The electrolyte solutions used are sulfuric acid (H2SO4) and chloride acid (HCl). The UV-Vis spectrum of the samples shows absorbance peaks at around 214 nm to 218 nm and shouldering peaks around 245 nm to 249 nm. The first peak corresponds to the existence of copper (Cu) ionic liquid in the solution, whereas the shouldering peak is related to the occurrence of GO material. A comparison between UV-Vis spectral of graphite in dimethylformamide (DMF) and GO in Cu ionic liquid in DMF resulted in the existence of a blue shift which signifies the production of Cu ionic liquid from the Cu coils inside the electrolyte solution. Increasing the concentration of the solution increases the absorbance peaks. Furthermore, raising the number of loops yields in the increase of the absorbance value at the first peaks that show Cu ionic liquid, but tends to decrease the absorbance value of the shouldering peaks of the GO material.

CARBON NANOCOMPOSITE COATED TEXTILE-BASED SENSOR: SENSING MECHANISM AND DURABILITY

2021 ◽  
Author(s):  
AMIT CHAUDHARI ◽  
SAGAR DOSHI ◽  
MADISON WEISS ◽  
DAE HAN SUNG ◽  
ERIK THOSTESON
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Electrical Resistance ◽  
Wearable Sensors ◽  
Composite Films ◽  
Large Change ◽  
Dip Coating ◽  
Porous Coating ◽  
Sensing Mechanism ◽  
Smart Garments

Carbon nanotube (CNT) composite films are deposited onto stretchable knit fabrics using electrophoretic deposition (EPD) and dip-coating techniques, which are industrially scalable processes for producing future wearable sensors. The deposited CNTs create an electrically conductive nanocomposite film on the surface of the fibers. These nanocomposite coated fabrics exhibit piezoresistive properties; under mechanical deformation/stretching, a large change in the electrical resistance is observed. Polyethyleneimine (PEI) functionalized carbon nanotubes deposited using EPD create a uniform, extremely thin porous coating on the fiber. Initial results show ultrahigh sensitivity of the carbon nanotube coated fabric when tested on elbow/knee to detect range of motion. The sensitivity of these sensors is exceptionally high when compared to a typical carbon nanotube-based polymer nanocomposite. The nanocomposite coating does not affect fabric's breathability or flexibility, making the sensor comfortable to wear. Because of these unique properties, tremendous potential exists for their use in functional/smart garments. Changes in electrical resistance for these fabrics are influenced by a combination of electron tunneling between the carbon nanotubes and the microstructure of the fabric. To investigate and characterize the unique sensing mechanism, the nanotube coated knit fabric's electromechanical response is studied at different length scales, from individual yarns to fabric levels. For applications in wearable sensors, the durability of the nanotube coating on the fabric is critical for repeatable and reliable sensing response. Durability testing of the sensing fabric for washing loads was conducted to study the nanotube coating's robustness. CNT coating's adhesion quality is evaluated based on the weight loss in the specimen and loss in electrical conductivity in each wash cycle. This research addresses the potential of these sensors for functional/smart garments by examining the underlying mechanism of the sensor response and the durability of the carbon nanotube coating.

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