scholarly journals Polyurethane Nanocomposites Containing Reduced Graphene Oxide, FTIR, Raman, and XRD Studies

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Michał Strankowski ◽  
Damian Włodarczyk ◽  
Łukasz Piszczyk ◽  
Justyna Strankowska
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Science And Technology ◽  
Structural Defects ◽  
Functionalized Graphene ◽  
Polyurethane Elastomers ◽  
Reduced Graphene ◽  
The Matrix ◽  
Xrd Studies ◽  
Polyurethane Nanocomposites

Recently, graphene and other graphene-based materials have become an essential part of composite science and technology. Their unique properties are not only restricted to graphene but also shared with derivative compounds like graphene oxide, reduced graphene oxide, functionalized graphene, and so forth. One of the most structurally important materials, graphene oxide (GO), is prepared by the oxidation of graphite. Though removal of the oxide groups can create vacancies and structural defects, reduced graphene oxide (rGO) is used in composites as effective filler similar to GO. Authors developed a new polyurethane nanocomposite using a derivative of grapheme, thermally reduced graphene oxide (rGO), to modify the matrix of polyurethane elastomers, by rGO.

Simultaneous Electrochemical Detection of Multiple Heavy-Metal Ions Based on Furfural/Reduced Graphene Oxide Composites

2021 ◽  
Author(s):  
Xiaoyun Xu ◽  
Xiaoyi Lv ◽  
Fei Tan ◽  
Yanping Li ◽  
Chao Geng ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Graphene Oxide ◽  
Metal Ions ◽  
Reduced Graphene Oxide ◽  
Heavy Metal Ions ◽  
Simultaneous Detection ◽  
Reduced Graphene ◽  
The Matrix ◽  
One Step ◽  
Oxide Composites

Abstract An efficient and sensitive electrochemical sensor for simultaneous detection of heavy metal ions was developed based on furfural/reduced graphene oxide composites (FF/RGO). The preparation of FF/RGO were performed through a one-step high-pressure assisted hydrothermal treatment, which is recommended as a green, convenient, and efficient way for the reduction of graphene oxide and the production of FF/RGO composites. RGO not only serves as the skeleton for furfural loading but also improves the conductivity of the composites in the matrix. FF/RGO with large specific surface area and abundant oxygen-containing functional groups was used to provide more binding sites for the effificient adsorption of heavy-metal ions due to the interaction between hydrophilic groups (-COOH, -OH, and -CHO) and metal cations. The developed sensor showed identifiable electrochemical response toward the heavy metal ions separately and simultaneously, exhibiting superior stability, outstanding sensitivity, selectivity and excellent analytical performance. Impressively, the sensor developed in this experiment has been successfully applied to the simultaneous determination of various heavy metal ions in actual samples, which has definitely exhibited a promising prospect in practical application.

Poly(3,4-ethylenedioxythiophene)-Ionic Liquid Functionalized Graphene/Reduced Graphene Oxide Nanostructures: Improved Conduction and Electrochromism

2011 ◽  
Vol 3 (4) ◽  
pp. 1115-1126 ◽  
Author(s):  
Aditya P. Saxena ◽  
Melepurath Deepa ◽  
Amish G. Joshi ◽  
Shweta Bhandari ◽  
Avanish Kumar Srivastava
Keyword(s):  
Ionic Liquid ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Functionalized Graphene ◽  
Oxide Nanostructures ◽  
Reduced Graphene

Modified Reduced Graphene Oxide with Enhanced Solubility and Conductivity and its Application

2014 ◽  
Vol 989-994 ◽  
pp. 859-862
Author(s):  
Xiao Peng Zeng
Keyword(s):  
Graphene Oxide ◽  
Hydrazine Hydrate ◽  
Reduced Graphene Oxide ◽  
Phenyl Isocyanate ◽  
Functionalized Graphene ◽  
Step Method ◽  
Reduced Graphene ◽  
Enhanced Solubility ◽  
Modified Graphene ◽  
Additional Reduction

Graphene oxide was modified with phenyl isocyanate first, and then reduced by a two step method-reduction with hydrazine hydrate first and an additional reduction in H2/Ar. The reduction with hydrazine hydrate in the first step can effectively remove the epoxy groups on the graphene, and the disposure of reduced graphene oxide (RGO) with H2 will change the residual amides and carbamate esters into conjugated C=N-ph structure. The introduced phenyl isocyanate not only acts as a functionalized group to prevent the aggregation of graphene but also will increase the electron concentration because of additional benzene. The resulted functionalized graphene can well dispersed in DMF, and the electrical conductivity of the functionalized graphene can reach 3.42×104S/m,which is far high than the method only reduce with the chemical reductant or H2/Ar. The prepared functionalized graphene is beneficial for the fabrication of graphene-based polymer nanocomposites. The conductivity of resulted modified graphene/PMMA composite with 5wt% filler content is 3.2S/m.

scholarly journals Reinforcing Mechanism of Reduced Graphene Oxide on Flexural Strength of Geopolymers: A Synergetic Analysis of Hydration and Chemical Composition

Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1723 ◽  
Author(s):  
Wu-Jian Long ◽  
Tao-Hua Ye ◽  
Qi-Ling Luo ◽  
Yaocheng Wang ◽  
Liu Mei
Keyword(s):  
Graphene Oxide ◽  
Chemical Composition ◽  
Flexural Strength ◽  
Reduced Graphene Oxide ◽  
Isothermal Calorimetry ◽  
Structural Defects ◽  
X Ray Diffraction ◽  
Simultaneous Formation ◽  
Reduced Graphene ◽  
Calcium Aluminosilicate

With the development of nanotechnology, reduced graphene oxide (rGO) has been used to improve the flexural strength of geopolymers. However, the reinforcing mechanism of rGO nanosheets on the flexural strength of geopolymers remains unclear. Here, this reinforcing mechanism was investigated from the perspectives of hydration and chemical composition. The effect of the reduction degree on rGO-reinforced geopolymers was also studied using isothermal calorimetry (IC), X-ray diffraction (XRD), and nuclear magnetic resonance (NMR) tests. Results show that the hydration degree and flexural strength of geopolymers effectively increase due to rGO addition. After alkali reduction at a temperature of 60 °C, rGO nanosheets have maximum reinforcement on the flexural strength of geopolymers with an increment of 51.2%. It is attributed to the promotion of slag hydration, as well as the simultaneous formation of calcium silicate hydrate with low Ca/Si ratio (C-S-H(I)) and calcium aluminosilicate hydrate (C-A-S-H) phases due to the inhibiting effect of rGO nanosheets on Al substitution on the end-of-chain silicates of C-S-H and C-A-S-H gels. In addition, different reduction degrees have almost no effect on the chemical composition of rGO-reinforced geopolymers, while excessive reduction impairs the improving effect of rGO nanosheets on the hydration process and flexural strength of geopolymers due to significant structural defects.

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