scholarly journals Thermal Conductivity Measurement of Graphene Composite

2013 ◽  
Vol 1456 ◽  
Author(s):  
Jiuning Hu ◽  
Wonjun Park ◽  
Xiulin Ruan ◽  
Yong P. Chen
Keyword(s):  
Thermal Conductivity ◽  
Graphene Oxide ◽  
Room Temperature ◽  
Detrimental Effect ◽  
Conductivity Measurement ◽  
Filler Concentration ◽  
3Ω Method ◽  
Graphene Composite ◽  
Reduced Graphene ◽  
Novel Method

ABSTRACTGraphene composites (GCs) have attracted much attention recently. It is interesting to explore thermal properties of GCs in which graphene filler concentrations are tunable. Here, we use 3ω method to measure the thermal conductivity of GCs synthesized from reduced graphene oxide (RGO) dispersed in polystyrene. To avoid the detrimental effect of lithography processes to GCs, we have developed a novel method employing polyvinyl alcohol and poly(methyl methacrylate) (PMMA) as a holder film to transfer micrometer-sized metal heaters/sensors onto GC surface. Room temperature measurements of the thermal conductivity of GCs are performed. The thermal conductivity is enhanced by ∼ 35 % when adding 5 vol.% of RGO filler concentration. Our measurements will be helpful to probe and understand the thermal transport properties of graphene based composites.

Polyaniline-Reduced Graphene Oxide Nanosheets for Room Temperature NH3 Detection

2021 ◽  
Author(s):  
Junyu Chang ◽  
Xiaobo Zhang ◽  
Zhenming Wang ◽  
Chunsheng Li ◽  
Qi Hu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Room Temperature ◽  
Graphene Oxide Nanosheets ◽  
Reduced Graphene

Complete Characterization of Thermoelectric Materials by a Combined van der Pauw Approach and the Effect of Radiation Losses

2011 ◽  
Vol 1314 ◽  
Author(s):  
Johannes de Boor ◽  
Volker Schmidt
Keyword(s):  
Thermal Conductivity ◽  
Measurement Errors ◽  
Conductivity Measurement ◽  
Short Review ◽  
Complete Characterization ◽  
Radiative Heat Loss ◽  
Radiation Losses ◽  
Novel Method ◽  
Simple Estimation ◽  
Van Der Pauw

AbstractWe have recently presented a novel method for a complete thermoelectric characterization [J. de Boor, V. Schmidt. Adv. Mater. 22:4303, (2010)]. This method is based on the well-known electrical van der Pauw method and allows measurement of the electrical and thermal conductivity, the Seebeck coefficient and the thermoelectric figure of merit. After a short review of this method we will discuss the systematic measurement errors of the method. It turns out that radiative heat loss can affect the thermal conductivity measurement significantly. We will give a simple estimation for the relative error due to radiation losses and discuss error minimizing strategies.

scholarly journals Functionalized Reduced Graphene Oxide Thin Films for Ultrahigh CO2 Gas Sensing Performance at Room Temperature

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 623
Author(s):  
Monika Gupta ◽  
Huzein Fahmi Hawari ◽  
Pradeep Kumar ◽  
Zainal Arif Burhanudin ◽  
Nelson Tansu
Keyword(s):  
Thin Films ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Gas Sensor ◽  
Functional Groups ◽  
Recovery Time ◽  
Room Temperature ◽  
Co2 Gas ◽  
Reduced Graphene ◽  
Response And Recovery

The demand for carbon dioxide (CO2) gas detection is increasing nowadays. However, its fast detection at room temperature (RT) is a major challenge. Graphene is found to be the most promising sensing material for RT detection, owing to its high surface area and electrical conductivity. In this work, we report a highly edge functionalized chemically synthesized reduced graphene oxide (rGO) thin films to achieve fast sensing response for CO2 gas at room temperature. The high amount of edge functional groups is prominent for the sorption of CO2 molecules. Initially, rGO is synthesized by reduction of GO using ascorbic acid (AA) as a reducing agent. Three different concentrations of rGO are prepared using three AA concentrations (25, 50, and 100 mg) to optimize the material properties such as functional groups and conductivity. Thin films of three different AA reduced rGO suspensions (AArGO25, AArGO50, AArGO100) are developed and later analyzed using standard FTIR, XRD, Raman, XPS, TEM, SEM, and four-point probe measurement techniques. We find that the highest edge functionality is achieved by the AArGO25 sample with a conductivity of ~1389 S/cm. The functionalized AArGO25 gas sensor shows recordable high sensing properties (response and recovery time) with good repeatability for CO2 at room temperature at 500 ppm and 50 ppm. Short response and recovery time of ~26 s and ~10 s, respectively, are achieved for 500 ppm CO2 gas with the sensitivity of ~50 Hz/µg. We believe that a highly functionalized AArGO CO2 gas sensor could be applicable for enhanced oil recovery, industrial and domestic safety applications.

Sulfur–hydrazine hydrate-based chemical synthesis of sulfur@graphene composite for lithium–sulfur batteries

2018 ◽  
Vol 5 (4) ◽  
pp. 785-792 ◽  
Author(s):  
Jianmei Han ◽  
Baojuan Xi ◽  
Zhenyu Feng ◽  
Xiaojian Ma ◽  
Junhao Zhang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Chemical Synthesis ◽  
Hydrazine Hydrate ◽  
Rate Capability ◽  
Graphene Composite ◽  
Reduced Graphene ◽  
Lithium Sulfur Batteries ◽  
Good Rate Capability ◽  
Lithium Sulfur ◽  
Excellent Stability

A sulfur–hydrazine hydrate chemistry-based method is reported here to integrate the sulfur and N-doped reduced graphene oxide to obtain S@N-rGO composite with 76% sulfur. The as-obtained S@N-rGO composite displays a good rate capability and excellent stability.

Room temperature ethanol sensing by chemically reduced graphene oxide film

FlatChem ◽  
2021 ◽  
pp. 100317
Author(s):  
Punam Tiwary ◽  
S.G. Chatterjee ◽  
S.S. Singha ◽  
Rajat Mahapatra ◽  
Amit K. Chakraborty
Keyword(s):  
Graphene Oxide ◽  
Oxide Film ◽  
Reduced Graphene Oxide ◽  
Room Temperature ◽  
Reduced Graphene ◽  
Chemically Reduced Graphene Oxide ◽  
Ethanol Sensing

Reduced Graphene Oxide for Room Temperature Ammonia (NH3) Gas Sensor

2018 ◽  
Vol 18 (11) ◽  
pp. 7927-7932 ◽  
Author(s):  
Weiwei Li ◽  
Xian Li ◽  
Li Cai ◽  
Yilin Sun ◽  
Mengxing Sun ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Gas Sensor ◽  
Room Temperature ◽  
Reduced Graphene
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