Influence of Bulk Graphite Density on Electrical Conductivity

Rattanaweeranon, S.; Limsuwan, Pichet; Thongpool, Voranuch; Piriyawong, Veeradate; Asanithi, Piyapong

doi:10.1016/j.proeng.2012.02.061

Cited by 29 publications

(15 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In contrast, a lower density of the bulk materials owns plenty of the gaps (the space between the adjacent particles), which strongly reduces mobility of electrons, thus, resulting in a lower electrical conductivity of the bulk materials. Resistivity of pristine graphite is dependent on the compression of the sample as well ( Figure 4 a); it varies in the range 0.03–3.4 Ω cm, approaching the theoretical values [ 21 ]. The resistivity of GO (shown in a logarithmic scale in ( Figure 4 b) is much higher than that of graphite due to the presence of abundant oxygen groups in the backbone of graphene sheet, which interrupt the sp 2 π-electron network and consequently, GO becomes an insulator.…”

Section: Resultsmentioning

confidence: 87%

“…A Keithley 2601 Source Meter (GlobalTech Sourcing, North Hampton, NH, USA) was used for the conductivity measurement. The resistivity ( ρ ) was determined using the following equation [ 21 ]:

where, R is a resistance (Ω), A is a cross section area (m 2 ), l is length of the sample (m). The resistance of the samples was calculated from a slope of linear I-V characteristic curve ( Figure S1 ).…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Synthesis of Reduced Graphene Oxide with Adjustable Microstructure Using Regioselective Reduction in the Melt of Boric Acid: Relationship Between Structural Properties and Electrochemical Performance

et al. 2018

View full text Add to dashboard Cite

The melt of H3BO3 was used to reach a controllable reduced graphene oxide (rGO) synthesis protocol using a graphene oxide (GO) precursor. Thermogravimetric analysis and differential scanning calorimetry (TG/DSC) investigation and scanning electron microscopy (SEM) images have shown that different from GO powder, reduction of GO in the melt of H3BO3 leads to the formation of less disordered structure of basal graphene planes. Threefold coordinated boron atom acts as a scavenger of oxygen atoms during the process of GO reduction. Fourier-transform infrared (FTIR) spectra of synthesized products have shown that the complex of glycerol and H3BO3 acts as a regioselective catalyst in epoxide ring-opening reaction and suppress the formation of ketone C=O functional groups at vacancy sites. Thermal treatment at 800 °C leads to the increased concentration of point defects in the backbone structure of rGO. Synthesized materials were tested electrochemically. The electrochemical performance of these materials essentially differs depending on the preparation protocol. The highest charge/discharge rate and double-layer capacitance were found for a sample synthesized in the melt of H3BO3 in the presence of glycerol and treated at 800 °C. The effect of optimal porosity and high electrical conductivity on the electrochemical performance of prepared materials also were studied.

show abstract

Section: Resultsmentioning

confidence: 87%

“…A Keithley 2601 Source Meter (GlobalTech Sourcing, North Hampton, NH, USA) was used for the conductivity measurement. The resistivity ( ρ ) was determined using the following equation [ 21 ]:

Section: Methodsmentioning

confidence: 99%

Synthesis of Reduced Graphene Oxide with Adjustable Microstructure Using Regioselective Reduction in the Melt of Boric Acid: Relationship Between Structural Properties and Electrochemical Performance

et al. 2018

View full text Add to dashboard Cite

show abstract

“…According to the production cost, host matrix features or functionalization possibilities, the use of other carbon materials cannot be discarded. Thus, in addition to MWCNT [41][42][43] and CNF [33,40], the bulk electrical conductivity under compaction of a wide variety of carbon materials has been measured: synthetic and natural graphite [41][42][43][48][49][50][51][52], petroleum and isotropic coke [49,51], activated carbon [49,51], carbon black [41,42,49,51,[53][54][55], ordered mesoporous materials [56] and graphene, graphene oxide (GO) and reduced graphene oxide (rGO) [41][42][43]57].…”

Section: Introductionmentioning

confidence: 99%

Effect of oxygen and structural properties on the electrical conductivity of powders of nanostructured carbon materials

2018

View full text Add to dashboard Cite

This work reports a study of the electrical conductivity under compression of nanostructured carbon powders with different physicochemical properties (texture, chemical-surface and morphology): a commercial carbon black (Vulcan XC-72R) and synthesized ordered mesoporous carbon (OMC), carbon nanocoils (CNC) and carbon nanofibers (CNF). The electrical conductivity was determined from the sample resistance under compaction (from 0.5 to 140 MPa) using the four-probe technique. A comparison of intrinsic and grain electrical conductivities (calculated according to the percolation theory and the general effective media approximation) was performed. Additionally, samples were subjected to chemical oxidation or graphitization treatments to evaluate the effect of oxygen content and structural properties on the electrical conductivity. In spite of the physicochemical differences of carbon materials, an exponential decrease of the electrical conductivity with the oxygen amount was stated. Finally, thermal treatment of OMC at 1500 °C led to a surprising increase in its conductivity due to the graphitization of the amorphous carbon structure of the original material and the oxygen removal.

show abstract

“…The main research hypothesis in this research was that there lies a tradeoff between the achievable density and the ease with which complex shapes can be fabricated so a hybrid method can balance these requirements. The combination of techniques can lead to lower porosity and improved mechanical and physical properties of complicated-shaped manufactured parts 27 , 28 . Determination of process critical steps and the parameters critical for achieving the density improvement were found which are being reported in this work.…”

Section: Introductionmentioning

confidence: 99%

Novel hybrid method to additively manufacture denser graphite structures using Binder Jetting

Popov

Fleisher

Muller‐Kamskii

et al. 2021

Sci Rep

View full text Add to dashboard Cite

This study introduces two hybrid processes integrating an additive manufacturing technique with post-processing treatments namely (i) Binder Jetting Printing (BJP) + Cold Isostatic Pressing (CIP) + cycle and (ii) BJP + cycle where cycle refers to a sequence of Impregnation—Drying—Pyrolysis. These two new processes yielded additively manufactured parts with higher density and reduced defects/porosities. As a testbed, we used these new processes to fabricate graphite structures. The samples produced by both methods were compared with each other and benchmarked to the samples produced by (a) BJP alone and (b) Traditional uniaxial pressing like compaction moulding. Various characterisation methods were used to investigate the microstructure and mechanical properties which showed that the porosity of hybrid manufactured samples reduces from 55% to a record 7%. This technological pathway is expected to create a new avalanche of industrial applications that are hitherto unexplored in the arena of hybrid additive manufacturing with BJP method.

show abstract

Influence of Bulk Graphite Density on Electrical Conductivity

Cited by 29 publications

References 2 publications

Synthesis of Reduced Graphene Oxide with Adjustable Microstructure Using Regioselective Reduction in the Melt of Boric Acid: Relationship Between Structural Properties and Electrochemical Performance

Synthesis of Reduced Graphene Oxide with Adjustable Microstructure Using Regioselective Reduction in the Melt of Boric Acid: Relationship Between Structural Properties and Electrochemical Performance

Effect of oxygen and structural properties on the electrical conductivity of powders of nanostructured carbon materials

Novel hybrid method to additively manufacture denser graphite structures using Binder Jetting

Contact Info

Product

Resources

About