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

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.

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Analysis of oxidation degree of graphite oxide and chemical structure of corresponding reduced graphite oxide by selecting different-sized original graphite

RSC Advances ◽

10.1039/c8ra01486h ◽

2018 ◽

Vol 8 (31) ◽

pp. 17209-17217 ◽

Cited By ~ 24

Author(s):

Lu Shen ◽

Lihua Zhang ◽

Kui Wang ◽

Lijing Miao ◽

Qiaofeng Lan ◽

...

Keyword(s):

Graphite Oxide ◽

Chemical Structure ◽

Chemical Properties ◽

Thermal Reduction ◽

Physical And Chemical Properties ◽

Oxidation Degree ◽

Reduced Graphite Oxide ◽

Physical And Chemical ◽

And Chemical Properties

The thermal reduction of GO is the most commonly used strategy for preparation of rGO, and the oxidation degree of GO would influence the chemical structure of prepared rGO, thereby affecting its physical and chemical properties.

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Thermal conductivity of epoxy composites filled by thermally reduced graphite oxide with different reduction degree

Journal of Composite Materials ◽

10.1177/0021998317696137 ◽

2017 ◽

Vol 51 (12) ◽

pp. 1743-1752 ◽

Cited By ~ 14

Author(s):

Yingying Sun ◽

Lin Chen ◽

Jun Lin ◽

Peng Cui ◽

Meicheng Li ◽

...

Keyword(s):

Thermal Conductivity ◽

Graphite Oxide ◽

Annealing Temperature ◽

Thermal Reduction ◽

Epoxy Composites ◽

Reduction Degree ◽

Conductivity Enhancement ◽

Interfacial Bonding Strength ◽

Reduced Graphite Oxide ◽

Out Of Plane

A series of selectively reduced graphite oxide was prepared by thermal reduction of graphite oxide at different annealing temperatures and used as fillers to enhance thermal conductivity of epoxy composites. The reduction degree of selectively reduced graphite oxide increases with annealing temperature changing from 600℃ to 1000℃. The out-of-plane thermal conductivity ( Κo) of selectively reduced graphite oxide/epoxy composites is remarkably higher than that of graphite oxide/epoxy. For the selectively reduced graphite oxide obtained at 1000℃, Κo reaches 0.674 W/m·K when filler content is 5.4 wt%, which is 450% of pure epoxy. The enhanced Κo can be attributed to the better dispersion of selectively reduced graphite oxide in epoxy and their edges overlap to form effective thermal conductive paths in epoxy matrix. However, the achieved thermal conductivity enhancement is still comparatively lower than that of selectively reduced graphite oxide with higher reduction degree, since the interfacial bonding strength between selectively reduced graphite oxide and epoxy decreases when reduction degree of selectively reduced graphite oxide flakes becomes higher.

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

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.302.170 ◽

2013 ◽

Vol 302 ◽

pp. 170-175 ◽

Cited By ~ 1

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.

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Study the Thermal Stability of Nitrogen Doped Reduced Graphite Oxide Supported Copper Catalyst

Journal of Cluster Science ◽

10.1007/s10876-018-1382-6 ◽

2018 ◽

Vol 29 (4) ◽

pp. 709-718 ◽

Cited By ~ 2

Author(s):

Alyaa K. Mageed ◽

A. B. Dayang Radiah ◽

A. Salmiaton ◽

Shamsul Izhar ◽

Musab Abdul Razak

Keyword(s):

Thermal Stability ◽

Graphite Oxide ◽

Copper Catalyst ◽

Nitrogen Doped ◽

Reduced Graphite Oxide ◽

Supported Copper Catalyst ◽

Thermal Stability Of

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Sulfur encapsulated in thermally reduced graphite oxide as a cathode for Li–S batteries

RSC Advances ◽

10.1039/c7ra12694h ◽

2018 ◽

Vol 8 (10) ◽

pp. 5298-5305 ◽

Cited By ~ 4

Author(s):

Xinbo Xu ◽

Jiafeng Ruan ◽

Yuepeng Pang ◽

Tao Yuan ◽

Shiyou Zheng

Keyword(s):

Electrochemical Properties ◽

Graphite Oxide ◽

Composite Cathode ◽

Thermal Reduction ◽

Oxide Materials ◽

Oxidation Degree ◽

Reduced Graphite Oxide ◽

The Matrix ◽

Superior Electrochemical Properties

Reduced graphite oxide materials with different oxidation degree were investigated as the matrix to load sulfur by an in situ thermal-reduction and intercalation strategy. The C/S composite cathode exhibits a superior electrochemical properties.

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Investigation of Hydrothermally Stressed Silicone Rubber/Silica Micro and Nanocomposite for the Coating High Voltage Insulation Applications

Materials ◽

10.3390/ma14133567 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3567

Author(s):

Faiza Faiza ◽

Abraiz Khattak ◽

Safi Ullah Butt ◽

Kashif Imran ◽

Abasin Ulasyar ◽

...

Keyword(s):

Silicone Rubber ◽

Structural Changes ◽

Polymer Chains ◽

Hydrothermal Conditions ◽

Silica Filler ◽

Before And After ◽

Aging Conditions ◽

The Stability ◽

Micro Silica ◽

Applied Stresses

Silicone rubber is a promising insulating material that has been performing well for different insulating and dielectric applications. However, in outdoor applications, environmental stresses cause structural and surface degradations that diminish its insulating properties. This effect of degradation can be reduced with the addition of a suitable filler to the polymer chains. For the investigation of structural changes and hydrophobicity four different systems were fabricated, including neat silicone rubber, a micro composite (with 15% micro-silica filler), and nanocomposites (with 2.5% and 5% nanosilica filler) by subjecting them to various hydrothermal conditions. In general, remarkable results were obtained by the addition of fillers. However, nanocomposites showed the best resistance against the applied stresses. In comparison to neat silicone rubber, the stability of the structure and hydrophobic behavior was better for micro-silica, which was further enhanced in the case of nanocomposites. The inclusion of 5% nanosilica showed the best results before and after applying aging conditions.

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Synthesis and Characterization of Reduced Graphene Oxide

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.678.56 ◽

2013 ◽

Vol 678 ◽

pp. 56-60 ◽

Cited By ~ 16

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.

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Effect of Graphite Oxide Dispersion Evaluated with Multifractal on Mechanical Properties and Thermal Stability of Poly(3hydroxybutyrate-co -4hydroxybutyrate)/Graphite Oxide Biocomposites

Advances in Polymer Technology ◽

10.1002/adv.21676 ◽

2016 ◽

Vol 37 (2) ◽

pp. 376-383 ◽

Cited By ~ 1

Author(s):

Jia Yang ◽

Yuli Wang ◽

Qiang Chen ◽

Gang Qin ◽

Shuzheng Liu

Keyword(s):

Mechanical Properties ◽

Thermal Stability ◽

Graphite Oxide ◽

Oxide Dispersion ◽

Thermal Stability Of

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Influence of Thermal Annealing on the Electrical Properties of Poly(3-hexylthiophene)-Based Thin Film Diodes

Zeitschrift für Naturforschung A ◽

10.1515/zna-2007-10-1109 ◽

2007 ◽

Vol 62 (10-11) ◽

pp. 609-619 ◽

Cited By ~ 8

Author(s):

Zivayi Chiguvare ◽

Jürgen Parisi ◽

Vladimir Dyakonov

Keyword(s):

Thin Film ◽

Thermal Annealing ◽

Indium Tin Oxide ◽

Bulk Heterojunction ◽

Polymer Chains ◽

Hole Injection ◽

Before And After ◽

Output Characteristics ◽

Al Thin Film ◽

Poly Styrene Sulfonate

The effects of thermal annealing on the bulk transport properties of poly(3-hexylthiophene) (P3HT) were studied by analyzing room temperature current-voltage characteristics of polymer thin films sandwiched between indium tin oxide/poly[ethylene dioxythiophene]:poly[styrene sulfonate] (ITO/PEDOT:PSS) and aluminum electrodes, before and after a thermal annealing step. It was observed that annealing takes place in two steps: (1) Dedoping of the polymer of impurities such as oxygen, remnant solvent, water, leading to a decrease in the conductivity of the film, and (2) thermally induced motion of the polymer chains leading to closer packing, thus, stronger inter-chain interaction and, consequently, increase in conductivity. It was also observed that the ITO/PEDOT:PSS/P3HT hole injection barrier increases on annealing the ITO/PEDOT:PSS/P3HT/Al thin film devices. The implications of impurity dedoping and closer packing on the output characteristics of bulk heterojunction polymer-fullerene thin film solar cells are discussed.

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