Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Enhanced Reduction of Graphene Oxide on Recyclable Cu Foils to Fabricate Graphene Films with Superior Thermal Conductivity.

ABSTRACT: Large-area freestanding graphene films are facilely fabricated by reducing graphene oxide films on recyclable Cu foils in H2-containing atmosphere at high temperature. Cu might act as efficient catalysts for considerably improved reduction of graphene oxide according to the SEM, EDS, XRD, XPS, Raman and TGA results. Comparing to the graphene films with ~30 ?m thickness reduced without Cu substrate at 900?°C, the thermal conductivity and electrical conductivity of graphene films reduced on Cu foils are enhanced about 140% to 902 Wm(-1)K(-1) and 3.6 × 10(4) S/m, respectively. Moreover, the graphene films demonstrate superior thermal conductivity of ~1219 Wm(-1)K(-1) as decreasing the thickness of films to ~10 ?m. The graphene films also exhibit excellent mechanical properties and flexibility.

SUBMITTER: Huang SY

PROVIDER: S-EPMC4585894 | biostudies-other | 2015

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Publications

Enhanced Reduction of Graphene Oxide on Recyclable Cu Foils to Fabricate Graphene Films with Superior Thermal Conductivity.

Huang Sheng-Yun SY Zhao Bo B Zhang Kai K Yuen Matthew M F MM Xu Jian-Bin JB Fu Xian-Zhu XZ Sun Rong R Wong Ching-Ping CP

Scientific reports 20150925

Large-area freestanding graphene films are facilely fabricated by reducing graphene oxide films on recyclable Cu foils in H2-containing atmosphere at high temperature. Cu might act as efficient catalysts for considerably improved reduction of graphene oxide according to the SEM, EDS, XRD, XPS, Raman and TGA results. Comparing to the graphene films with ~30 μm thickness reduced without Cu substrate at 900 °C, the thermal conductivity and electrical conductivity of graphene films reduced on Cu foi ...[more]

PMID: 26404674

Similar Datasets

Controlling pore structure and conductivity in graphene nanosheet films through partial thermal exfoliation.

Project description:Thermal exfoliation is an efficient and scalable method for the production of graphene nanosheets or nanoplatelets, which are typically re-assembled or blended to form new macroscopic "graphene-based materials". Thermal exfoliation can be applied to these macroscopic graphene-based materials after casting to create internal porosity, but this process variant has not been widely studied, and can easily lead to destruction of the physical form of the original cast body. Here we explore how the partial thermal exfoliation of graphene oxide (GO) multilayer nanosheet films can be used to control pore structure and electrical conductivity of planar, textured, and confined GO films. The GO films are shown to exfoliate explosively when the instrument-set heating rates are 100 K/min and above leading to complete destruction of the film geometry. Textured films with engineered micro-wrinkling and crumpling show similar thermal behavior to planar films. Here, we also demonstrate a novel method to produce fairly large size intact rGO films of high electrical conductivity and microporosity based on confinement. Sandwiching GO precursor films between inert plates during partial exfoliation at 250°C produces high conductivity and porosity material in the form of a flexible film that preserves the macroscopic structure of the original cast body.

| S-EPMC7901814 | biostudies-literature

High-quality PVD graphene growth by fullerene decomposition on Cu foils.

Project description:We present a new protocol to grow large-area, high-quality single-layer graphene on Cu foils at relatively low temperatures. We use C60 molecules evaporated in ultra high vacuum conditions as carbon source. This clean environment results in a strong reduction of oxygen-containing groups as depicted by X-ray photoelectron spectroscopy (XPS). Unzipping of C60 is thermally promoted by annealing the substrate at 800ºC during evaporation. The graphene layer extends over areas larger than the Cu crystallite size, although it is changing its orientation with respect to the surface in the wrinkles and grain boundaries, producing a modulated ring in the low energy electron diffraction (LEED) pattern. This protocol is a self-limiting process leading exclusively to one single graphene layer. Raman spectroscopy confirms the high quality of the grown graphene. This layer exhibits an unperturbed Dirac-cone with a clear n-doping of 0.77 eV, which is caused by the interaction between graphene and substrate. Density functional theory (DFT) calculations show that this interaction can be induced by a coupling between graphene and substrate at specific points of the structure leading to a local sp3 configuration, which also contribute to the D-band in the Raman spectra.

| S-EPMC5428744 | biostudies-literature

Strain-controlled thermal conductivity in ferroic twinned films.

Project description:Large reversible changes of thermal conductivity are induced by mechanical stress, and the corresponding device is a key element for phononics applications. We show that the thermal conductivity κ of ferroic twinned thin films can be reversibly controlled by strain. Nonequilibrium molecular dynamics simulations reveal that thermal conductivity decreases linearly with the number of twin boundaries perpendicular to the direction of heat flow. Our demonstration of large and reversible changes in thermal conductivity driven by strain may inspire the design of controllable thermal switches for thermal logic gates and all-solid-state cooling devices.

| S-EPMC4165272 | biostudies-literature

Growth of Graphene/h-BN Heterostructures on Recyclable Pt Foils by One-Batch Chemical Vapor Deposition.

Project description:High-quality large-area graphene/h-BN vertical heterostructures are promising building blocks for many viable applications such as energy harvesting/conversion, electronics and optoelectronics. Here, we successfully grew high-quality large-area graphene/h-BN vertical heterostructures on Pt foils by one-batch low-pressure chemical vapor deposition (LPCVD). We obtained the high quality of about 200-µm-wide graphene/h-BN film having uniform layer thickness. Moreover, the obtained graphene/h-BN heterostructures exhibited field effect mobility of up to 7,200 cm2V-1s-1 at room temperature. These results suggest that such graphene/h-BN heterostructures on recyclable Pt foils grown by LPCVD are promising for high-performance graphene-based electronics.

| S-EPMC5719054 | biostudies-literature

Significant Reduction of Interfacial Thermal Resistance and Phonon Scattering in Graphene/Polyimide Thermally Conductive Composite Films for Thermal Management.

Project description:The developing flexible electronic equipment are greatly affected by the rapid accumulation of heat, which is urgent to be solved by thermally conductive polymer composite films. However, the interfacial thermal resistance (ITR) and the phonon scattering at the interfaces are the main bottlenecks limiting the rapid and efficient improvement of thermal conductivity coefficients (λ) of the polymer composite films. Moreover, few researches were focused on characterizing ITR and phonon scattering in thermally conductive polymer composite films. In this paper, graphene oxide (GO) was aminated (NH2-GO) and reduced (NH2-rGO), then NH2-rGO/polyimide (NH2-rGO/PI) thermally conductive composite films were fabricated. Raman spectroscopy was utilized to innovatively characterize phonon scattering and ITR at the interfaces in NH2-rGO/PI thermally conductive composite films, revealing the interfacial thermal conduction mechanism, proving that the amination optimized the interfaces between NH2-rGO and PI, reduced phonon scattering and ITR, and ultimately improved the interfacial thermal conduction. The in-plane λ (λ ||) and through-plane λ (λ ⊥) of 15 wt% NH2-rGO/PI thermally conductive composite films at room temperature were, respectively, 7.13 W/mK and 0.74 W/mK, 8.2 times λ || (0.87 W/mK) and 3.5 times λ ⊥ (0.21 W/mK) of pure PI film, also significantly higher than λ || (5.50 W/mK) and λ ⊥ (0.62 W/mK) of 15 wt% rGO/PI thermally conductive composite films. Calculation based on the effective medium theory model proved that ITR was reduced via the amination of rGO. Infrared thermal imaging and finite element simulation showed that NH2-rGO/PI thermally conductive composite films obtained excellent heat dissipation and efficient thermal management capabilities on the light-emitting diodes bulbs, 5G high-power chips, and other electronic equipment, which are easy to generate heat severely.

| S-EPMC7931127 | biostudies-literature

Dopamine-Mediated Graphene Bridging Hexagonal Boron Nitride for Large-Scale Composite Films with Enhanced Thermal Conductivity and Electrical Insulation.

Project description:Heat accumulation generated from confined space poses a threat to the service reliability and lifetime of electronic devices. To quickly remove the excess heat from the hot spot, it is highly desirable to enhance the heat dissipation in a specific direction. Herein, we report a facile route to fabricate the large-scale composite film with enhanced thermal conductivity and electrical insulation. The well-stacked composite films were constructed by the assembly of polydopamine (PDA)-modified graphene nanosheets (GNSPDA) and hexagonal boron nitride (BNPDA), as well as bacterial cellulose (BC). The introduction of the PDA layer greatly improves the interface compatibility between hybrid fillers and BC matrix, and the presence of GNSPDA-bridging significantly increases the probability of effective contact with BNPDA fillers, which is beneficial to form a denser and complete "BN-GNS-BN" heat conduction pathway and tight filler-matrix network, as supported by the Foygel model fitting and numerical simulation. The resulting BC/BNPDA/GNSPDA film shows the thermal conductivity and tensile strength of 34.9 W·m-1·K-1 and 30.9 MPa, which separately increases to 161% and 155% relative to the BC/BNPDA film. It was found that the low electrically conductive and high thermal conductive properties can be well balanced by tuning the mass ratio of GNSPDA at 5 wt%, and the electrical conductivity caused by GNSPDA can be effectively blocked by the BNPDA filler network, giving the low electrical conductivity of 1.8 × 10-10 S·cm-1. Meanwhile, the BC/BNPDA/GNSPDA composite films effectively transfer the heat and diminish the hot-spot temperature in cooling LED chip module application. Thus, the present study may pave the way to promoting the industrialization of scalable thermal management devices.

| S-EPMC10097086 | biostudies-literature

Controlling the thermal conductivity of multilayer graphene by strain.

Project description:Straintronics is a new concept to enhance electronic device performances by strain for next-generation information sensors and energy-saving technologies. The lattice deformation in graphene can modulate the thermal conductivity because phonons are the main heat carriers. However, the device fabrication process affects graphene's heat transport properties due to its high stretchability. This study experimentally investigates the change in the thermal conductivity when biaxial tensile strain is applied to graphene. To eliminate non-strain factors, two mechanisms are considered: pressure-induced and electrostatic attraction-induced strain. Raman spectroscopy and atomic force microscopy precisely estimate the strain. The thermal conductivity of graphene decreases by approximately 70% with a strain of only 0.1%. Such thermal conductivity controllability paves the way for applying graphene as high-efficiency thermal switches and diodes in future thermal management devices.

| S-EPMC8486806 | biostudies-literature

Hierarchically Multifunctional Polyimide Composite Films with Strongly Enhanced Thermal Conductivity.

Project description:The development of lightweight and integration for electronics requires flexible films with high thermal conductivity and electromagnetic interference (EMI) shielding to overcome heat accumulation and electromagnetic radiation pollution. Herein, the hierarchical design and assembly strategy was adopted to fabricate hierarchically multifunctional polyimide composite films, with graphene oxide/expanded graphite (GO/EG) as the top thermally conductive and EMI shielding layer, Fe3O4/polyimide (Fe3O4/PI) as the middle EMI shielding enhancement layer and electrospun PI fibers as the substrate layer for mechanical improvement. PI composite films with 61.0 wt% of GO/EG and 23.8 wt% of Fe3O4/PI exhibits high in-plane thermal conductivity coefficient (95.40 W (m K)-1), excellent EMI shielding effectiveness (34.0 dB), good tensile strength (93.6 MPa) and fast electric-heating response (5 s). The test in the central processing unit verifies PI composite films present broad application prospects in electronics fields.

| S-EPMC8664909 | biostudies-literature

Growth of millimeter-size single crystal graphene on Cu foils by circumfluence chemical vapor deposition.

Project description:A simply and reproducible way is proposed to significantly suppress the nucleation density of graphene on the copper foil during the chemical vapor deposition process. By inserting a copper foil into a tube with one close end, the nucleation density on the copper foils can be reduced by more than five orders of magnitude and an ultra-low nucleation density of ~10?nucleus/cm(2) has been achieved. The structural analyses demonstrate that single crystal monolayer graphene with a lateral size of 1.9?mm can be grown on the copper foils under the optimized growth condition. The electrical transport studies show that the mobility of such single crystal graphene is around 2400?cm(2)/Vs.

| S-EPMC3971397 | biostudies-literature

Superior thermal conductivity in suspended bilayer hexagonal boron nitride.

Project description:We reported the basal-plane thermal conductivity in exfoliated bilayer hexagonal boron nitride h-BN that was measured using suspended prepatterned microstructures. The h-BN sample suitable for thermal measurements was fabricated by dry-transfer method, whose sample quality, due to less polymer residues on surfaces, is believed to be superior to that of PMMA-mediated samples. The measured room temperature thermal conductivity is around 484 Wm(-1)K(-1)(+141 Wm(-1)K(-1)/ -24 Wm(-1)K(-1)) which exceeds that in bulk h-BN, providing experimental observation of the thickness-dependent thermal conductivity in suspended few-layer h-BN.

| S-EPMC4855177 | biostudies-other

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data