Optical Properties of Films of Graphite Oxide, Reduced Graphite Oxide and its Intercalated Compounds with Ammonium Dodecahydro-closo-Dodecaborate

2013 ◽  
Vol 302 ◽  
pp. 170-175 ◽  
Author(s):  
Alexander A. Karpenko ◽  
Vitaly I. Saldin
Keyword(s):  
Optical Properties ◽  
Optical Density ◽  
Graphite Oxide ◽  
Light Radiation ◽  
Intercalated Compounds ◽  
Reduced Graphite Oxide ◽  
Before And After ◽  
Carbon Release ◽  
Oxidized Graphite ◽  
Transmission And Absorption

The influence of light radiation with different wavelengths (546, 380, 365 nm) on the coatings of oxidized graphite and its intercalated compound with ammonium dodecahydrododecaborate (NH4)2B12H12 was studied. The transmission and absorption spectra of the coatings were measured before and after irradiation. It was shown that the optical density of the coatings increased because of carbon release (blackening), which was especially strong during UV irradiation. Under the same conditions (wavelength, power, time), the change in the optical density was much larger for the intercalated compound than for oxidized graphite. This can be explained by the presence of the anion B12H12 2- in the former. It is not appropriate to refer to graphite oxide or reduced graphite oxide simply as graphene since their properties are substantially different.

scholarly journals Static and Dynamic Behavior of Polymer/Graphite Oxide Nanocomposites before and after Thermal Reduction

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1008
Author(s):  
Kiriaki Chrissopoulou ◽  
Krystalenia Androulaki ◽  
Massimiliano Labardi ◽  
Spiros H. Anastasiadis
Keyword(s):  
Graphite Oxide ◽  
Thermal Reduction ◽  
Polymer Chains ◽  
Solid Surfaces ◽  
Relaxation Processes ◽  
Thermal Transitions ◽  
Reduced Graphite Oxide ◽  
Before And After ◽  
Similarities And Differences ◽  
Thermal Stability Of

Nanocomposites of hyperbranched polymers with graphitic materials are investigated with respect to their structure and thermal properties as well as the dynamics of the polymer probing the effect of the different intercalated or exfoliated structure. Three generations of hyperbranched polyester polyols are mixed with graphite oxide (GO) and the favorable interactions between the polymers and the solid surfaces lead to intercalated structure. The thermal transitions of the confined chains are suppressed, whereas their dynamics show similarities and differences with the dynamics of the neat polymers. The three relaxation processes observed for the neat polymers are observed in the nanohybrids as well, but with different temperature dependencies. Thermal reduction of the graphite oxide in the presence of the polymer to produce reduced graphite oxide (rGO) reveals an increase in the reduction temperature, which is accompanied by decreased thermal stability of the polymer. The de-oxygenation of the graphite oxide leads to the destruction of the intercalated structure and to the dispersion of the rGO layers within the polymeric matrix because of the modification of the interactions between the polymer chains and the surfaces. A significant increase in the conductivity of the resulting nanocomposites, in comparison to both the polymers and the intercalated nanohybrids, indicates the formation of a percolated rGO network.

Optical properties of graphite oxide and reduced graphite oxide

2014 ◽  
Vol 47 (26) ◽  
pp. 265306 ◽  
Author(s):  
Eilho Jung ◽  
Seokbae Lee ◽  
Seulki Roh ◽  
Eunhee Hwang ◽  
Junghyun Lee ◽  
...  
Keyword(s):  
Optical Properties ◽  
Graphite Oxide ◽  
Reduced Graphite Oxide

Synthesis and Characterization of Reduced Graphene Oxide

2013 ◽  
Vol 678 ◽  
pp. 56-60 ◽  
Author(s):  
Cherukutty Ramakrishnan Minitha ◽  
Ramasamy Thangavelu Rajendrakumar
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Graphite Oxide ◽  
High Performance ◽  
Structural Changes ◽  
Epoxy Group ◽  
Xrd Analysis ◽  
Si Substrates ◽  
Reduced Graphene ◽  
Reduced Graphite Oxide

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.

Optical Properties of Nano-Structure Tungsten-Doped Vanadium Oxide

2012 ◽  
Author(s):  
W. B. Cai ◽  
F. Wang ◽  
Y. P. Miao ◽  
J. Wei ◽  
K. L. Zhang
Keyword(s):  
Optical Properties ◽  
Transition Temperature ◽  
Oxide Film ◽  
Vanadium Oxide ◽  
High Vacuum ◽  
Infrared Transmission ◽  
Dc Magnetron Sputtering ◽  
Nano Structure ◽  
Before And After ◽  
Deposited Film

Tungsten-doped vanadium oxide has been proved to decrease the transition temperature, which enables vanadium oxide film to be more promising. Besides, the nano-structure can improve the properties of the film when compared with the as-deposited film. In this letter, a nano-structure tungsten-doped vanadium oxide film is proposed. Tungsten-doped vanadium oxide film was deposited on the Si (400) substrate by DC magnetron sputtering. The doping level was controlled by adjusting the sputtering time. Then the as-deposited film was annealed to form a nano-structure film at the temperature of 500 °C for 1 h in high vacuum. The morphology and crystalline structure of such films were characterized by AFM and XRD, respectively. Optical properties of the films were tested by FTIR, mainly comparing the infrared transmission before and after annealing.

Calorimetric study of the low-temperature postradiation polymerization of tetrafluoroethylene in the presence of reduced graphite oxide

2014 ◽  
Vol 48 (1) ◽  
pp. 11-16
Author(s):  
G. A. Kichigina ◽  
P. P. Kushch ◽  
D. P. Kiryukhin ◽  
Yu. M. Shul’ga ◽  
S. A. Baskakov
Keyword(s):  
Low Temperature ◽  
Graphite Oxide ◽  
Calorimetric Study ◽  
Reduced Graphite Oxide

Sol–gel synthesis and optical properties of titanium dioxide thin film

2018 ◽  
Vol 32 (09) ◽  
pp. 1850076 ◽  
Author(s):  
Irfan Ullah ◽  
Shaukat Ali Khattak ◽  
Tanveer Ahmad ◽  
Saman ◽  
Nayab Ali Ludhi
Keyword(s):  
Thin Film ◽  
Titanium Dioxide ◽  
Optical Properties ◽  
Band Gap ◽  
Surface Defects ◽  
Sol Gel ◽  
Luminescent Properties ◽  
Localized States ◽  
Indirect Transition ◽  
Transmission And Absorption

The titanium dioxide (TiO2) is synthesized by sol–gel method using titanium-tetra-iso-propoxide (TTIP) as a starting material, and deposited on the pre-cleaned glass substrate using spin coating technique at optimized parameters. Energy dispersive X-ray (EDX) spectroscopy confirms successful TiO2 growth. The optical properties concerning the transmission and absorption spectra show 85% transparency and 3.28 eV wide optical band gap for indirect transition, calculated from absorbance. The exponential behavior of absorption edge is observed and attributed to the localized states electronic transitions, curtailed in the indirect band gap of the thin film. The film reveals decreasing refractive index with increasing wavelength. The photoluminescence (PL) study ascertains that luminescent properties are due to the surface defects.

Effect of graphite oxide structure on the formation of stable self-assembled conductive reduced graphite oxide hydrogel

2014 ◽  
Vol 2 (19) ◽  
pp. 3846 ◽  
Author(s):  
Yang Liu ◽  
Guo-Qiang Qi ◽  
Cheng-Lu Liang ◽  
Rui-Ying Bao ◽  
Wei Yang ◽  
...  
Keyword(s):  
Graphite Oxide ◽  
Oxide Structure ◽  
Reduced Graphite Oxide ◽  
Self Assembled
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