Method Article

Synthesis of Graphene Nanofluids with Controllable Flake Size Distributions

DOI:

10.3791/59740

⸱

July 17th, 2019

 , 
1Department of Mechanical and Automotive Engineering, South China University of Technology

In This Article

Summary

$$\rightleftharpoonup{xx}$$ $$\longleftharp{xx}$$, $$\longrightharp{xx}$$,

A method for synthesizing graphene nanofluids with controllable flake size distributions is presented.

Abstract

$$\rightleftharpoonup{xx}$$ $$\longleftharp{xx}$$, $$\longrightharp{xx}$$,

A method for synthesizing graphene nanofluids with controllable flake size distributions is presented. Graphene nanoflakes can be obtained by the exfoliation of graphite in the liquid phase, and the exfoliation time is used to control the lower limits of the graphene nanoflake size distributions. Centrifugation is successfully used to control the upper limits of the nanoparticle size distributions. The objective of this work is to combine exfoliation and centrifugation to control the graphene nanoflake size distributions in the resulting suspensions.

Introduction

$$\rightleftharpoonup{xx}$$ $$\longleftharp{xx}$$, $$\longrightharp{xx}$$,

Traditional methods used to synthesize graphene nanofluids often use sonication to disperse graphene powder1 in fluids, and sonication has been proven to change the size distribution of graphene nanoparticles2. Since the thermal conductivity of graphene depends on the flake length3,4, the synthesis of graphene nanofluids with controllable flake size distributions is vital to heat-transfer applications. Controlled centrifugation has been successfully applied to liquid exfoliated graphene dispersions to separate suspensions into fractions with different mean flake ....

Access restricted. Please log in or start a trial to view this content.

Protocol

$$\rightleftharpoonup{xx}$$ $$\longleftharp{xx}$$, $$\longrightharp{xx}$$,

1. Exfoliation of graphite in a liquid phase

  1. Preparation of reagents
    1. In a dry clean flat-bottom flask, add 20 g of polyvinyl alcohol (PVA), and then add 1,000 mL of distilled water.
      NOTE: If the suspension was not processed to satisfaction, the step could be repeated to obtain an additional suspension.
    2. Gently swirl the flask until the PVA fully dissolves.
      CAUTION: PVA is harmful to humans; thus, protective gloves and surgical masks should be used.
    3. Add 50 g of graphite powder to the flat-bottom flask, and gently swirl the flask until the graphite powder fully disperses in the suspension.
    4. Transfer 500 ....

Access restricted. Please log in or start a trial to view this content.

Results

$$\rightleftharpoonup{xx}$$ $$\longleftharp{xx}$$, $$\longrightharp{xx}$$,

The existence of graphene nanosheets can be validated by various characteristic techniques. Figure 1 shows the results of the UV-Vis measurement for the various flake size distributions produced by the abovementioned protocol. The spectra absorbance peak obtained at a wavelength of 270 nm is evidence of the graphene flakes. Different absorbances correspond to different concentrations. The lowest absorbance observed corresponds to the highest centrifugation speed. The spectra strongly confirm.......

Access restricted. Please log in or start a trial to view this content.

Discussion

$$\rightleftharpoonup{xx}$$ $$\longleftharp{xx}$$, $$\longrightharp{xx}$$,

We have proposed a methodology for synthesizing graphene nanofluids with controllable flake size distributions. The method combines two procedures: exfoliation and centrifugation. Exfoliation controls the lower size limit of the nanoparticles, and centrifugation controls the upper size limit of the nanoparticles.

Although we employed liquid-phase exfoliation of graphite to produce graphene nanoparticles, the following modifications to the protocol should be considered. Additional exfoliation p.......

Access restricted. Please log in or start a trial to view this content.

Disclosures

$$\rightleftharpoonup{xx}$$ $$\longleftharp{xx}$$, $$\longrightharp{xx}$$,

The authors have nothing to disclose.

Acknowledgements

$$\rightleftharpoonup{xx}$$ $$\longleftharp{xx}$$, $$\longrightharp{xx}$$,

This work was supported by the National Nature Science Foundation of China (Grant No. 21776095), the Guangzhou Science and Technology Key Program (Grant No. 201804020048), and Guangdong Key Laboratory of Clean Energy Technology (Grant No. 2008A060301002). We thank LetPub (www.letpub.com) for its linguistic assistance during the preparation of this manuscript.

....

Access restricted. Please log in or start a trial to view this content.

Materials

List of materials used in this article
NameCompanyCatalog NumberComments
BeakerChina Jiangsu Mingtai Education Equipments Co., Ltd.500 mL
BeakerChina Jiangsu Mingtai Education Equipments Co., Ltd.5000 mL
Deionized waterGuangzhou Yafei Water Treatment Equipment Co., Ltd.analytical grade
Electronic balanceShanghai Puchun Co., Ltd.JEa10001
Filter membraneChina Tianjin Jinteng Experiment Equipments Co., Ltd.0.2 micron
Graphite powderTianjin Dengke chemical reagent Co., Ltd.analytical grade
Hand glovesChina Jiangsu Mingtai Education Equipments Co., Ltd.
Laboratory shear mixerShanghai Specimen and Model Factoryjrj-300
Long neck flat bottom flaskChina Jiangsu Mingtai Education Equipments Co., Ltd.1000 ml
Nanoparticle analyzerHORIBA, Ltd.SZ-100Z
PVAShanghai Yingjia Industrial Development Co., Ltd.1788analytical grade
Raman spectrophotometerHORIBA, Ltd.Horiba LabRam 2
Scanning electron microscopeZeiss Co., Ltd.LEO1530VPSEM
Surgical maskChina Jiangsu Mingtai Education Equipments Co., Ltd.for one-time use
Thermal Gravimetric AnalyzerGerman NETZSCH Co., Ltd.NETZSCH TG 209 F1 LibraTGA analysis
Transmission electron microscopeJapan Electron Optics Laboratory Co., Ltd.JEM-1400plusTEM
UV-Vis spectrophotometerAgilent Technologies, Inc.+BB2:B18Varian Cary 60

Try the professional online HTML editor

References

$$\rightleftharpoonup{xx}$$ $$\longleftharp{xx}$$, $$\longrightharp{xx}$$,
  1. Sadeghinezhad, E., et al. A comprehensive review on graphene nanofluids: Recent research, development and applications. Energy Conversion and Management. 111, 466-487 (2016).
  2. Wang, W., et al.

Access restricted. Please log in or start a trial to view this content.

Reprints and Permissions

Request permission to reuse the text or figures of this JoVE article

Request Permission

Tags

Graphene NanofluidsGraphene ExfoliationCentrifugation ControlSize Distribution ControlLiquid Phase ExfoliationGraphene Nanoflake SynthesisUltraviolet Visible SpectroscopyRaman Spectroscopy AnalysisTransmission Electron MicroscopyScanning Electron Microscopy

Related Articles