Charge transport mechanism of thermally reduced graphene oxide and their fabrication for high performance shield against electromagnetic pollution

2016 ◽  
Vol 180 ◽  
pp. 413-421 ◽  
Author(s):  
Ramesh Kumar ◽  
S.K. Dhawan ◽  
H.K. Singh ◽  
Amarjeet Kaur
2013 ◽  
Vol 678 ◽  
pp. 56-60 ◽  
Author(s):  
Cherukutty Ramakrishnan Minitha ◽  
Ramasamy Thangavelu Rajendrakumar

Reduced graphene oxide is an excellent candidate for various electronic devices such as high performance gas sensors. In this work Graphene oxide was prepared by oxidizing graphite to form graphite oxide. From XRD analysis the peak around 11.5o confirmed that the oxygen was intercalated into graphite. By using hydrazine hydrate, the epoxy group in graphite oxide was reduced then the solution of reduced graphite oxide (rGO) is exfoliated. Raman spectrum of rGO contains both G band (1580 cm-1), D band (1350 cm-1). The remarkable structural changes reveals that reduction of graphene oxide from the values of ID/IG ratio that increase from 0.727 (GO) to 1.414 (rGO). The exfoliated reduced graphite oxide solution is spin coated on to the SiO2/Si substrates.


2021 ◽  
Vol 45 (7) ◽  
pp. 3581-3588
Author(s):  
Zhaokun Wang ◽  
Licong Jiang ◽  
Hongwei Pan ◽  
Yongyin Cui ◽  
Chengzhong Zong

A novel and environmentally-friendly resveratrol (RA) was used as an effective reagent for the preparation of reduced graphene oxide (rGO).


Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1112
Author(s):  
Raghvendra Singh Yadav ◽  
Anju ◽  
Thaiskang Jamatia ◽  
Ivo Kuřitka ◽  
Jarmila Vilčáková ◽  
...  

Superparamagnetic ZnFe2O4 spinel ferrite nanoparticles were prepared by the sonochemical synthesis method at different ultra-sonication times of 25 min (ZS25), 50 min (ZS50), and 100 min (ZS100). The structural properties of ZnFe2O4 spinel ferrite nanoparticles were controlled via sonochemical synthesis time. The average crystallite size increases from 3.0 nm to 4.0 nm with a rise of sonication time from 25 min to 100 min. The change of physical properties of ZnFe2O4 nanoparticles with the increase of sonication time was observed. The prepared ZnFe2O4 nanoparticles show superparamagnetic behavior. The prepared ZnFe2O4 nanoparticles (ZS25, ZS50, and ZS100) and reduced graphene oxide (RGO) were embedded in a polyurethane resin (PUR) matrix as a shield against electromagnetic pollution. The ultra-sonication method has been used for the preparation of nanocomposites. The total shielding effectiveness (SET) value for the prepared nanocomposites was studied at a thickness of 1 mm in the range of 8.2–12.4 GHz. The high attenuation constant (α) value of the prepared ZS100-RGO-PUR nanocomposite as compared with other samples recommended high absorption of electromagnetic waves. The existence of electric-magnetic nanofillers in the resin matrix delivered the inclusive acts of magnetic loss, dielectric loss, appropriate attenuation constant, and effective impedance matching. The synergistic effect of ZnFe2O4 and RGO in the PUR matrix led to high interfacial polarization and, consequently, significant absorption of the electromagnetic waves. The outcomes and methods also assure an inventive and competent approach to develop lightweight and flexible polyurethane resin matrix-based nanocomposites, consisting of superparamagnetic zinc ferrite nanoparticles and reduced graphene oxide as a shield against electromagnetic pollution.


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