Colloidal chemistry as a guide to design intended dispersions of carbon nanomaterials

https://doi.org/10.1016/j.mtchem.2021.100526Get rights and content

Highlights

  • Carbon-based dispersions prepared by different routes are presented.

  • Dispersion procedures to overcome van der Waals interactions in carbon nanomaterials.

  • Preparation of carbon dispersions are exposed in terms of colloidal interactions.

  • Colloidal interactions guiding the obtention of dispersions with specific properties.

  • Carbon-based inks without insulator molecules as passivant agents.

Abstract

In this review, some established concepts from Colloidal Science and their application to graphene and carbon nanotubes dispersions in organic or aqueous media are highlighted to rationalize alternatives for some issues in terms of colloidal properties. Recent applications for carbon-based dispersions are presented, as well as van der Waals interactions in carbon materials and strategies to overcome these interactions, such as increasing electrostatic repulsion between dispersed particles, surface functionalization, or adsorption of passivation agents such as macromolecules, which are the basis of many dispersion and exfoliation procedures. The demonstration of how knowledge and fine control of colloidal interactions have been used to overcome several limitations, such as the preparation of stable and concentrated dispersions of carbon materials and keeping appreciable electrical conductivity, is presented. It is also showed that the same knowledge can help the development of more environmentally friendly carbon-based colloids as well as the improvement of similar systems as dispersions of two-dimensional materials.

Introduction

Carbon-based inks are composed of carbon materials dispersed in liquid media, and they have been largely used for centuries in printing processes since Gutenberg's prints of the Bible in Mainz using carbon black inks [1] or in artistic works such as Roman frescos, Egyptian murals, and Japanese paintings, as shown in Fig. 1A [[2], [3], [4]], but their origin goes back to prehistoric times when the mankind was using charcoal inks (or only charcoal) to draw on caves walls [5,6]. Carbon inks composed of dispersed nanomaterials have gained importance since the reports by Coleman and collaborators using organic liquids to disperse carbon nanotubes [7] or to exfoliate pristine graphite [8] into monolayer and few-layer graphene and since the reports of graphene oxide (GO) dispersions in water [9] or polar solvents [10].

Carbon-based dispersions are composed of insoluble materials dispersed in a solvent or solution, and the majority are formed by sp2-hybridized carbon allotropes, such as graphite, graphene, carbon nanotubes, fullerenes, or carbon black that are electrical conductors [12,13] therefore, these dispersions can be classified as conductive inks. This type of inks can also be formed by other conductive materials such as conjugated polymers or metallic nanoparticles dispersed in liquids or solutions, and many works have investigated properties and applications of such systems aiming at flexible, organic, and/or printed electronic devices [[14], [15], [16], [17], [18], [19]].

There are a large number of works in the literature about different preparation routes and applications for dispersions of carbon nanomaterials [[20], [21], [22], [23], [24], [25], [26]]; however, recent reports have indicated that still there is room for new knowledge and applications for those systems, for example, (1) fabrication of field–effect transistor with an organic dispersion of semiconductor-enriched single-walled carbon nanotubes (SWCNT) showed in B [11], (2) graphite exfoliation using lithium and liquid ammonia into few-layer graphene that has properties not present in monolayer graphene or in bulk graphite [27], (3) fabrication of flexible electrodes based on conductive carbon inks derived from wood biomass [28], (4) inkjet printing of carbon-based dispersions electrostatically stabilized without insulating passivators [29], (5) preparation of turbostratic graphite from diverse sources by flash heating and dispersion of these materials in aqueous or organic media [30], and (6) fabrication of hydrovoltaic devices with carbon black inks [31,32], among many others recent reports that highlight the great potential of carbon-based colloidal systems.

Dispersions and inks are examples of colloids, and such systems have been investigated by almost two centuries since the pioneer work of Thomas Graham in the XIX century [33]. There are many theoretical and experimental studies in this field, including classical textbooks [[33], [34], [35], [36], [37]], and a deeper understanding of colloidal chemistry can guide the resolution of some issues in the field of carbon dispersions, such as the improvement of colloidal stability, mass concentration, exfoliation yield, and minimal use of additives, such as passivant agents or toxic solvents, as recent works have demonstrated [27,[38], [39], [40], [41], [42]].

There are many works on the literature concerning carbon-based conductive inks, presenting detailed preparation procedures, complex formulations with improved rheological properties, and different applications [[14], [15], [16], [17], [18],[43], [44], [45], [46]]; however, they will not be treated here. In this review, we focus on simple carbon colloids formed by one dispersed material (graphene or carbon nanotubes) and one dispersion medium (one solvent or solution) to highlight some basic colloidal properties relevant for carbon-based dispersions such as van der Waals (vdW) forces. We present some strategies used to overcome vdW interactions in carbon materials, but interpreting them in terms of colloidal interactions, and we show how the knowledge of some colloidal properties such as electrostatic and solvation interactions can guide the preparation and the improvement of carbon-based dispersions.

Section snippets

Carbon materials as vdW solids

Carbon allotropes are solids formed by carbon atoms bonded by covalent bonds. Among them, some allotropes formed by sp2-hybridized carbon atoms are special because they are formed by independent nanostructures, and these building units are stable as their respective bulk solids. This means that carbon nanostructures can exist independently from each other, in contrast to metallic nanoparticles for example, which are not stable without strong stabilizers attached on their surface, and without

Overcoming vdW forces in carbon materials

Eq. (1) is associated with vdW interactions for dispersed particles interacting across a liquid medium. However, it can be used to describe vdW interactions of carbon nanostructures in the solid state as a first approximation, keeping clearly that it is more complex and depends on the other factors (e.g. electronic properties for example, vdW interactions for metallic and semiconductor SWCNT can be different), but this same approach has been used for other authors to describe graphite

Outlooks

Although stabilization produced by adsorbed polymers and surfactants in general (such as amphiphilic molecules) or by functional groups are efficient in terms of maintaining particles dispersed for long periods and producing highly concentrated dispersions, due to the lyophilic nature of such colloids, especially with adsorbed polymers, these types of stabilization decrease the electrical contact between carbon materials after deposition because passivating molecules are insulators and

Concluding remarks

Preparation routes of carbon dispersions were interpreted in terms of colloidal interactions, which allowed to model dispersion and exfoliation procedures as means to overcome vdW interactions in carbon materials by decreasing their magnitude (e.g. intercalation procedures) and introducing opposite interactions to them (e.g. introducing electrostatic and solvation interactions). Procedures of liquid exfoliation applied for pristine carbon materials in organic media were highlighted because of

Authors’ contribution

J.P.V.D. has conceptualized the review in terms of subject and structure. Both authors have written and revised the paper.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgments

The authors acknowledge National Institute of Science & Technology in Bioanalytics (INCTBio, INCT-MCTI/CNPq/CAPES/FAPs nº 16/2014), Coordination for the Improvement of Higher Education Personnel (CAPES) (post-doc fellowship (J.P.V.D.) process: 88887.478317/2020–00), National Council for Scientific and Technological Development (CNPq) (Projects CNPq: 434303/2016-0 and MCTIC/CNPq/FNDCT/MS/SCTIE/Decit Nº 07/2020, and for the post-doc fellowship (J.P.V.D.) process: 301600/2021-0), and São Paulo

References (164)

  • L. Dong et al.

    A non-dispersion strategy for large-scale production of ultra-high concentration graphene slurries in water

    Nat. Commun.

    (2018)
  • N.O. Mchedlov-Petrossyan

    Fullerenes in molecular liquids. Solutions in “good” solvents: another view

    J. Mol. Liq.

    (2011)
  • J. Yan et al.

    A novel perspective on the formation of the solid electrolyte interphase on the graphite electrode for lithium-ion batteries

    Electrochim. Acta

    (2010)
  • S. Maurer et al.

    Henry coefficients of adsorption predicted from solid Hamaker constants

    Chem. Eng. Sci.

    (2001)
  • P. Tolias

    Lifshitz calculations of Hamaker constants for fusion relevant materials

    Fusion Eng. Des.

    (2018)
  • C. Knieke et al.

    Scalable production of graphene sheets by mechanical delamination

    Carbon

    (2010)
  • S. Yamanaka et al.

    Production of thin graphite sheets for a high electrical conductivity film by the mechanical delamination of ternary graphite intercalation compounds

    Carbon

    (2012)
  • P. Yu et al.

    Electrochemical exfoliation of graphite and production of functional graphene

    Curr. Opin. Colloid Interface Sci.

    (2015)
  • J.T.G. Overbeek

    Interparticle forces in colloid science

    Powder Technol.

    (1984)
  • H. Jäger et al.

    Carbon, 1. General

  • H.G. Friedstein

    A short history of the chemistry of painting

    J. Chem. Educ.

    (1981)
  • K. Eremin et al.

    Raman spectroscopy of Japanese artists' materials: the tale of Genji by tosa mitsunobu

    J. Raman Spectrosc.

    (2006)
  • P. Harris

    On charcoal

    Interdiscipl. Sci. Rev.

    (1999)
  • M. Placke et al.

    Drawing and writing materials

  • S. Giordani et al.

    Debundling of single-walled nanotubes by dilution: observation of large populations of individual nanotubes in amide solvent dispersions

    J. Phys. Chem. B

    (2006)
  • Y. Hernandez et al.

    High yield production of graphene by liquid phase exfoliation of graphite

    Nat. Nanotechnol.

    (2008)
  • J.I. Paredes et al.

    Graphene oxide dispersions in organic solvents

    Langmuir

    (2008)
  • M.D. Bishop et al.

    Fabrication of carbon nanotube field-effect transistors in commercial silicon manufacturing facilities

    Nat. Electron.

    (2020)
  • M.S. Dresselhaus et al.

    Science of Fullerenes and Carbon Nanotubes

    (1996)
  • A.K. Geim et al.

    The rise of graphene

    Nat. Mater.

    (2007)
  • A. Kamyshny et al.

    Conductive nanomaterials for printed electronics

    Small

    (2014)
  • D. Li et al.

    Printable transparent conductive films for flexible electronics

    Adv. Mater.

    (2018)
  • G. Mattana et al.

    Inkjet-printing: a new fabrication technology for organic transistors

    Adv. Mater. Technol.

    (2017)
  • W. Yang et al.

    Graphene and the related conductive inks for flexible electronics

    J. Mater. Chem. C

    (2016)
  • D. Parviz et al.

    Challenges in liquid-phase exfoliation, processing, and assembly of pristine graphene

    Adv. Mater.

    (2016)
  • L. Niu et al.

    Production of two-dimensional nanomaterials via liquid-based direct exfoliation

    Small

    (2016)
  • T. Premkumar et al.

    Carbon nanotubes in the liquid phase: addressing the issue of dispersion

    Small

    (2012)
  • A. Ciesielski et al.

    Graphene via sonication assisted liquid-phase exfoliation

    Chem. Soc. Rev.

    (2014)
  • B.G. Márkus et al.

    Ultralong spin lifetime in light alkali atom doped graphene

    ACS Nano

    (2020)
  • Q. Fu et al.

    Wood-based flexible electronics

    ACS Nano

    (2020)
  • D.X. Luong et al.

    Gram-scale bottom-up flash graphene synthesis

    Nature

    (2020)
  • Z. Zhang et al.

    Emerging hydrovoltaic technology

    Nat. Nanotechnol.

    (2018)
  • G. Xue et al.

    Water-evaporation-induced electricity with nanostructured carbon materials

    Nat. Nanotechnol.

    (2017)
  • R.J. Hunter

    Foundations of Colloid Science

    (2001)
  • D.J. Shaw

    Introduction to Colloid and Surface Chemistry

    (1992)
  • A.W. Adamson et al.

    Physical Chemistry of Surfaces

    (1997)
  • J.N. Israelachvili

    Intermolecular and Surface Forces

    (2011)
  • H.-J. Butt et al.

    Physics and Chemistry of Interfaces

    (2003)
  • G. Bepete et al.

    Surfactant-free single-layer graphene in water

    Nat. Chem.

    (2017)
  • Z.-L. Cheng et al.

    Li+/Na+ Co-assisted hydrothermal exfoliation for graphite into few-layer graphene nanosheets and their excellent friction-reducing performance

    ACS Sustain. Chem. Eng.

    (2019)
  • Cited by (9)

    • From radicals destabilization to stable fullerenol nanoaggregates

      2022, Carbon Trends
      Citation Excerpt :

      Low-modified fullerenols are composed by dispersed nanoaggregates with mean diameters between about 50 and 300 nm [3,5,17,21], mass concentration [3,6,22,23] ranging from 0.075 to 3.5 mg mL−1 (or close values usually), and have colloidal properties dependent on the functionalization degree and dispersant [17]. Carbon-based colloids without passivating agents as these fullerenol nanoaggregates are stabilized mainly by solvation and electrostatic interactions [16], and both are linked with the presence and concentration of functional groups. While solvation is generated by intermolecular interactions between modified surface and solvent molecules, electrostatic stabilization is achieved when charged functional groups are bonded to the surface such as deprotonated hydroxyl groups reported for fullerenol nanoaggregates in water [5,7,8,23].

    • A Glance at Dysprosium Oxide Free Powders

      2023, Current Materials Science
    View all citing articles on Scopus

    This review is dedicated to the victims of the corona virus, and it is a protest against the destruction of Brazilian environment.

    View full text