Reduced graphene oxide / epoxy nanocomposites with enhanced dielectric, mechanical, thermomechanical and thermal properties

2021 ◽  
pp. 009524432110541
Author(s):  
Rahnamol Akkalamattam Maitheenkunju ◽  
Jayalatha Gopalakrishnan

Epoxy/conducting filler nanocomposites with high dielectric performance have emanated as a promising material in electronic and electrical industry. In this work, a facile and low-cost method, that is, thermal reduction at 400°C was adopted for the preparation of reduced graphene oxide (rGO) from graphene oxide (GO). The rGO was characterized by X-ray diffraction analysis, Fourier transform infrared spectroscopy, Raman spectroscopy, Field emission scanning electron microscopy and Transmission electron microscopy. Epoxy nanocomposite presented a dielectric permittivity of 35 at 1.8 vol.% loading of rGO (Ep/G-1.8) at 103 Hz, which was 5 times higher than neat epoxy and with a low dielectric loss. With the addition of 0.3 vol.% of rGO (Ep/G-0.3), the mechanical properties such as tensile strength, Young’s modulus and impact strength were enhanced by 34%, 56% and 54%, respectively. Dynamic mechanical analysis (DMA) revealed that in comparison to epoxy, there was a tremendous enhancement of storage modulus (55%) and the glass transition temperature (Tg) exhibited a remarkable shift of 39°C towards higher temperature for Ep/G-0.3. Cross-link density and coefficient of effectiveness (C-factor) estimated from the storage modulus improved significantlyfor Ep/G-0.3. Theoretical modelling was done on the viscoelastic properties of the composites. SEM studies indicated the uniform dispersion of rGO throughout in the epoxy matrix. Thermogravimetric analysis revealed that inclusion of rGO improved the thermal stability of epoxy nanocomposites.

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 594 ◽  
Author(s):  
Mara Serrapede ◽  
Marco Fontana ◽  
Arnaud Gigot ◽  
Marco Armandi ◽  
Glenda Biasotto ◽  
...  

A simple, low cost, and “green” method of hydrothermal synthesis, based on the addition of l-ascorbic acid (l-AA) as a reducing agent, is presented in order to obtain reduced graphene oxide (rGO) and hybrid rGO-MoO2 aerogels for the fabrication of supercapacitors. The resulting high degree of chemical reduction of graphene oxide (GO), confirmed by X-Ray Photoelectron Spectroscopy (XPS) analysis, is shown to produce a better electrical double layer (EDL) capacitance, as shown by cyclic voltammetric (CV) measurements. Moreover, a good reduction yield of the carbonaceous 3D-scaffold seems to be achievable even when the precursor of molybdenum oxide is added to the pristine slurry in order to get the hybrid rGO-MoO2 compound. The pseudocapacitance contribution from the resulting embedded MoO2 microstructures, was then studied by means of CV and electrochemical impedance spectroscopy (EIS). The oxidation state of the molybdenum in the MoO2 particles embedded in the rGO aerogel was deeply studied by means of XPS analysis and valuable information on the electrochemical behavior, according to the involved redox reactions, was obtained. Finally, the increased stability of the aerogels prepared with l-AA, after charge-discharge cycling, was demonstrated and confirmed by means of Field Emission Scanning Electron Microscopy (FESEM) characterization.


2018 ◽  
Vol 42 (3) ◽  
pp. 2081-2088 ◽  
Author(s):  
Man Zhang ◽  
Wei Hong ◽  
Ruinan Xue ◽  
Lingzhi Li ◽  
Guanbo Huang ◽  
...  

At present, low-cost and efficient electrocatalysts for accelerating the oxygen reduction reaction in fuel cells are highly desired.


2018 ◽  
Vol 33 (1) ◽  
pp. 85-96
Author(s):  
Thangamani Rajkumar ◽  
Nagamuthu Muthupandiyan ◽  
Chinnaswamy Thangavel Vijayakumar

Reduced graphene oxide (RGEO) and N-[4-(chlorocarbonyl)phenyl]maleimide-functionalized reduced graphene oxide (MFRGEO) were used as nanofillers for polymethyl methacrylate (PMMA) matrix nanocomposites to enhance thermal stability. Methyl methacrylate containing nanofiller of four different weight percent (0.2, 0.4, 0.6, and 0.8) was polymerized using ultrasonic radiation-assisted bulk polymerization. The Fourier-transform infrared spectra showed the absence of chemical interaction between the filler and the matrix phase. Morphology of nanocomposites studied using scanning electron microscope confirmed the assistance aided by ultrasonication in the uniform dispersion of nanofiller in the PMMA matrix. Thermogravimetric (TG) study revealed the presence of MFRGEO enhanced the thermal stability of PMMA by shifting the entire degradation to higher temperature. The thermal stability of PMMA nanocomposite was improved by as much as 40°C at just 0.8 wt% loading of MFRGEO. Differential TG study also supported the role of maleimide functionalization on RGEO in the enhancement of thermal stability of PMMA by means of retarding the degradation rate of unsaturated chain ends in the PMMA matrix. Unlike MFRGEO, RGEO failed to enhance the thermal stability of PMMA.


RSC Advances ◽  
2017 ◽  
Vol 7 (56) ◽  
pp. 35004-35011 ◽  
Author(s):  
Suling Yang ◽  
Gang Li ◽  
Chen Qu ◽  
Guifang Wang ◽  
Dan Wang

A new kind of ZnO nanoparticle/N-doped reduced graphene oxide nanocomposite (ZnONPs/N-rGO) was synthesized through a low temperature, low-cost and one step hydrothermal process.


2019 ◽  
Vol 297 ◽  
pp. 31-39 ◽  
Author(s):  
Pooria Moozarm Nia ◽  
Ebrahim Abouzari-Lotf ◽  
Pei Meng Woi ◽  
Yatimah Alias ◽  
Teo Ming Ting ◽  
...  

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