Graphene Technology E-Book

• Herausgeber: Wiley-VCH
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 449

Veröffentlichungsjahr: 2016

Beschreibung

Filling the gap between publications for industrial developers and academic researchers on graphene synthesis and its applications, this book presents the essential aspects for the successful upscaling of graphene production. After an introduction to graphene, its synthesis and characterization, the text covers a wide variety of graphene composites and compounds. The larger part of the book discusses various applications where graphene has been successfully integrated into technologies, including uses in the energy sector, oil and gas industry, biomedical areas, sensors and coatings. Finally, the book concludes with a summary and a look at the future of graphene technology, including a market review. With its focus on applications, this is equally useful for both academic and industrial users.

Leseprobe

Table of Contents

Cover

Title Page

Copyright

List of Contributors

Chapter 1: Graphene Technology: The Nanomaterials Road Ahead

1.1 Newly Discovered 2D Materials

1.2 Wonder Materials

1.3 The Rise of MPM

1.4 Addressing the Environment, Health, and Safety

1.5 The Nanomaterials Road Ahead

1.6 Can Graphene Survive the “Disillusionment” Downturn?

Chapter 2: Graphene Synthesis

2.1 Introduction

2.2 Definitions

2.3 Characterization of Graphene by Raman Spectroscopy

2.4 Epitaxial Growth of Graphene from SiC

2.5 Graphene by Chemical-Vapor-Deposition

2.6 Delamination of Graphene from Graphite

2.7 Wet-Chemical Functionalization and Defunctionalization

2.8 Synthesis of Nanographene from Small Molecules

References

Chapter 3: Graphene Composites

3.1 Introduction

3.2 Preparation and Properties of Graphene

3.3 Functionalization of Graphene

3.4 Preparation of Graphene Polymer Composites

3.5 Characterization of Graphene-Polymer Composites

3.6 Properties of Graphene/Polymer Composites

3.7 Application of Graphene Based Polymer Composites

3.8 Conclusions and Outlook

References

Chapter 4: Graphene in Lithium-ion Batteries

4.1 Introduction

4.2 Renewable Energies

4.3 Batteries, What are They?

4.4 Lithium-ion Batteries

4.5 Anodes, Cathodes, and Electrolytes

4.6 Carbon Materials

4.7 Graphite

4.8 Graphene

4.9 Graphene in Lithium-Ion Batteries

4.10 Graphene in Anodes

4.11 Graphene in Cathodes

4.12 Graphene in Other Types of Lithium Batteries

Summary

References

Chapter 5: Graphene-Based Membranes for Separation Engineering

5.1 Introduction

5.2 Preparation of Graphene-Based Membranes

5.3 Graphene-based Membranes for Separation Applications

5.4 Conclusions

Acknowledgments

References

Chapter 6: Graphene Coatings for the Corrosion Protection of Base Metals

6.1 Introduction to Corrosion

6.2 Bare Graphene as a Protective Barrier

6.3 Graphene Nanocomposites for Corrosion Inhibition

6.4 Graphene/Metal Nanocomposites for Corrosion Inhibition

6.5 Graphene/Ceramic Nanocomposites for Corrosion Inhibition

6.6 Summary and Future Outlook

Acknowledgments

References

Chapter 7: Graphene Market Review

7.1 Introduction

7.2 Graphene Market: Past and Present

7.3 Co-ordinated Market Initiatives

7.4 Market and Application Projections

7.5 Conclusion

References

Chapter 8: Financing Graphene Ventures

8.1 Graphene Start-ups

8.2 The Art of Raising Capital

8.3 Shifting Financial Landscape for Graphene Ventures

8.4 The Graphene Financing Road Ahead

Summary

Appendix Nantero Case Study – The Funding and Evolution of a Nanomaterials Start-up

The Founding of Nantero

Series A: Financing Round

Post-Series A: Funding Evolution

Series B: Financing Round

Post-Series B: Funding Evolution

Series C: Financing Round

Post-Series C: Funding Evolution

Series D: Financing Round

Post-Series D: Funding Evolution

Series E: Financing Round

Summary

Index

End User License Agreement

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Guide

Cover

Table of Contents

Begin Reading

List of Illustrations

Chapter 1: Graphene Technology: The Nanomaterials Road Ahead

Figure 1.1 Gartner's hype cycle.

Figure 1.2 2-D nanomaterials enable more powerful batteries. (Peleg and Mertens,

The Graphene Batteries Market Report

, 2015.)

Figure 1.3 Thermal conductivity of thermoplastic/graphene in different loading of graphene.

Chapter 2: Graphene Synthesis

Figure 2.1 (a) Chemical structure motive of AB stacked graphite. (b) Graphene with zigzag and arm-chair edges. (c) Restacked layers of graphene and few-layer graphene. (d) A flake of natural graphite. (From Ref. [2] with permission from Wiley-VCH Verlag GmbH & Co, Copyright 2014.) (e) High resolution transmission emission spectroscope (HR-TEM) image of one layer of graphene. (Reprinted from Ref. [3] with permission from Macmillan Publishers Ltd: Nature Communications, Copyright 2014.) (f) Selected moiré pattern of twisted bi-layer graphene. (Reprinted from Ref. [4] with permission from Macmillan Publishers Ltd: Nature, Copyright 2011.)

Figure 2.2 (a) Raman spectra of graphene (top) and graphene with defects (bottom) with the most relevant peaks labeled with D, G, and 2D. (b) Illustrations of selected excitation and emission processes responsible for the G, D, and 2D peak. (Adapted from Ref. [6] with permission from Macmillan Publishers Ltd: Nature Nanotechnology, Copyright 2013.)

Figure 2.3 (a) Raman spectra of graphene with different densities of defects. Left: defect density about 1–3% (no sharp 2D peak); right: density of defects of 0.03%. (b) Reference Raman spectra of graphene that relate to densities of defects between 0.005% and 0.77%. (Reproduced from Ref. [9] with permission from American Chemical Society, Copyright (2011).) (c) Illustration of an idealized distance pattern of defects of 10 nm. (From Ref. [2] with permission from Wiley-VCH Verlag GmbH & Co, Copyright 2014.)

Figure 2.4 (a) Plotted data of the statistical Raman microscopic (SRM) analysis of films of graphene with different densities of defects;

I

D

/

I

G

versus Γ

2D

(full-width at half-maximum (FWHM) of the 2D peak). Graphene derived from graphene oxide using different reducing agents. [12] – published by The Royal Society of Chemistry; (b) SRM maps of multi-layered films of functionalized graphene derived from the reaction of C

8

K (a donor graphite intercalation compound) and 4-

tert

-butylphenyldiazonium tetrafluoroborate. Local variations of the functionalization are visualized by plotting

I

2D

/

I

G

or

I

D

/

I

G

versus

x

,

y

-positions. (Adapted from Ref. [13] with permission from Macmillan Publishers Ltd: Nature Chemistry, Copyright 2011.)

Figure 2.5 (a) Illustration of the growth of graphene on SiC. (Reproduced from Ref. [20] with permission from Macmillan Publishers Ltd: Nature Chemistry, Copyright 2009.) (b) Top: Raman spectra of graphene and bi-layer graphene on SiC, and bottom: spectra obtained after SiC-background spectra subtraction, shown for graphene and bi-layer graphene [21]. (c) High resolution transmission electron microscope image of graphene (overview) and (d) magnification that displays the intact honeycomb lattice. (Reproduced from Ref. [22] with permission from The Royal Society of Chemistry.)

Figure 2.6 Illustration of the formation process of graphene grown on a catalytically active metal surface, such as copper; (a) copper substrate with oxides on top; (b) growth of islands of graphene and grains illustrated; (c) patches of graphene merging forming grain boundaries. (Reproduced from Ref. [25] with permission from The Royal Society of Chemistry.)

Figure 2.7 (a) Illustration of the transfer of graphene from the metal catalyst by PMMA coating, metal etching, transfer on the desired substrate, followed by dissolution of the polymer, leaving graphene back on the substrate. (Reprinted from Ref. [26] with permission from American Chemical Society, Copyright 2013.) (b) AFM images of graphene films transferred onto SiO

2

, displaying cracks and wrinkles. (Reproduced from Ref. [25] with permission from The Royal Society of Chemistry.) (c) (A): image of graphene grown on a foil of copper and visualized by scanning electron microscopy (SEM); (B): magnification SEM image of graphene on copper with wrinkles, grains, and steps; (C): transferred graphene on isolating SiO

2

/Si wafer; (D): transferred graphene on a glass slide. (Reprinted from Ref. [26] with permission from the American Chemical Society, Copyright 2013.)

Figure 2.8 Mechanical cleavage of graphene from graphite using adhesive tape. Graphene is deposited on to SiO

2

/Si wafers and identified by optical microscopy and AFM. (Reproduced from Ref. [35] with permission from The Royal Society of Chemistry.)

Figure 2.9 Illustration of the adaption of processing parameters, such as stress intensity or viscosity of the solvent, using also beads of different size. Optimization of the yield of flakes with a reasonable lateral dimension of hundreds of nanometer of graphene and few-layer graphene is possible. Adaption of processing parameters improve the delamination efficiency and reduce the formation of defects within the carbon framework. (Reprinted from Ref. [38] with permission from Springer Science+Business Media, Copyright 2015.)

Figure 2.10 (a) Raman spectra of graphite (upper spectrum) and graphene (lower spectrum). The FWHM (27.4 cm

−1

) of the 2D peak is characteristic for graphene. (b) Analysis of SRM data illustrating the quality of graphene and few-layer graphene. The quality of the product increased with improving the processing parameter for the stirred media milling process. Parameters such as, size of beads, viscosity or energy input were optimized. (Reprinted from Ref. [38] with permission from Springer Science+Business Media, Copyright 2015.)

Figure 2.11 (a) TEM image of graphene and few-layer graphene after sonication of graphite in

N

-methylpyrrolidone for 312 h. (Reprinted from Ref. [41] with permission from the American Chemical Society. Copyright 2011.) (b) Polydisperse surfactant-stabilized dispersion of graphene and few-layer graphene. Density gradient ultra-centrifugation (DGU) yielded fractions of graphene, bilayer, and few-layer graphene. (c) Fractions of stabilized graphene, separated by DGU, with related AFM images and height profiles. (d) Raman spectra of graphene fractions prepared by DGU, F4 fraction relates to graphene. (Reprinted from Ref. [42] with permission from the American Chemical Society, Copyright 2009.)

Figure 2.12 Selection of surfactants suitable to stabilize graphene and few-layer graphene in aqueous solution [39].

Figure 2.13 Preparation of graphene and few-layer graphene by shear mixing. Graphene can be identified by Raman spectra even if graphene is a minor fraction among few-layer graphene. X-ray photoelectron spectroscopy can identify C–N bonds originating from NMP solvent. HR-TEM images reveal areas of an intact honeycomb lattice. (Reprinted from Ref. [44] with permission from Macmillan Publishers Ltd: Nature Materials, Copyright 2014.)

Figure 2.14 The water soluble bolaamphiphile, comprising a perylene moiety as well as carboxylic acids, was used to delaminate graphene from graphite in water without the need of sonication or shear forces. (From Ref. [2] with permission from Wiley-VCH Verlag GmbH & Co, Copyright 2014, and Ref. [45], Copyright 2009.)

Figure 2.15 (a) Illustration of the proposed mechanism of electrochemical exfoliation, involving the generation of reactive oxygen species that lead to partial exfoliation of the carbon layers, followed by sulfate penetration of layers and delamination to graphene and few-layer graphene. (b) AFM image of graphene and statistical analysis of the number of layers. (Reprinted from Ref. [47] with permission from the American Chemical Society, Copyright 2013.)

Figure 2.16 (a) Illustration of the functionalization route producing a graphite intercalation compound, dispersing it in a solvent to generate graphenide, followed by addition of an electrophile, here aryliodide. (b) Thermal defunctionalization of addends forms stacks of graphene. The D peak that is induced by defects (here due to phenyl-addends) is thermally removed. (From Ref. [52] with permission from Wiley-VCH Verlag GmbH & Co, Copyright 2014.)

Figure 2.17 (a) Top: Reaction of graphenide with the electrophile hexyl iodide to hexyl-functionalized graphene. (From Ref. [2] with permission from Wiley-VCH Verlag GmbH & Co, Copyright 2014.) Bottom: Raman spectra of graphite, graphene, and functionalized graphene. (Reproduced from Ref. [53] with permission from The Royal Society of Chemistry.) (b) Top: Wet-chemical hydrogenation of graphenide by protons to form fluorescent partially hydrogenated graphene. Bottom: Temperature dependent Raman spectroscopy that depicts the reversibility of the hydrogenation by heating the sample to 700 °C. (From Ref. [54] with permission from Wiley-VCH Verlag GmbH & Co, Copyright 2013.)

Figure 2.18 Chemical sketch for the oxidation of graphite to graphene oxide. (Reprinted from Ref. [58] with permission from Springer Science+Business Media, Copyright 2014.)

Figure 2.19 General illustration of the synthesis of GO. Graphite becomes intercalated and activated, followed by oxidation. Aqueous work-up yields graphite oxide and GO after delamination. (Reprinted from Ref. [58] with permission from Springer Science+Business Media, Copyright 2014.)

Figure 2.20 Historical development of the synthesis of GrO and GO, respectively. (Reprinted from Ref. [58] with permission from Springer Science+Business Media, Copyright 2014.)

Figure 2.21 Chemical sketch for the illustration of functional groups in GO that bears defects. At both sides of the basal plane, there are hydroxyl groups, epoxy groups, and organosulfate groups. At edges of defects and edges of flakes there are possibly hydroxyl groups, ketones, actetals, carboxylic acids, lactol groups, and organosulfate groups in arbitrary amounts. A defect with a proposed structure that comprises one carbonyl group and a hemi-acetal is shown as well. (From Ref. [2] with permission from Wiley-VCH Verlag GmbH & Co, Copyright 2014.)

Figure 2.22 (a) Proposed general reduction mechanism of GO with an almost intact carbon framework, also called oxo-functionalized graphene. Oxo-groups attached to graphene are protonated and reductively cleaved on both sides of the basal plane. (b) Raman spectroscopic studies reveal that both sides of the basal plane are efficiently reduced, even if only one side of oxo-functionalized graphene is accessible for the reducing agent. Red, Reduction with HI/TFA from the top; blue, reduction with ascorbic acid (AS) from the lower side; and green, stepwise reduction from both sides [77].

Figure 2.23 (a) Illustration of the defect density in graphene derived from GO with different defect densities; left: σ-hole defects within the carbon framework with a defect density of several percentage values (residual functional groups omitted); right: graphene from oxo-functionalized graphene with an almost intact carbon framework and Raman spectra of derived graphene. (b) Schematic of the synthesis of oxo-functionalized graphene with an almost intact carbon framework and related graphene. (From Ref. [2] with permission from Wiley-VCH Verlag GmbH & Co, Copyright 2014.) (c) Schematic of the synthesis of oxo-functionalized graphene from graphite sulfate and related graphene. (From Ref. [72] with permission from Wiley-VCH Verlag GmbH & Co, Copyright 2015.)

Figure 2.24 SRM data for graphene from (a) almost intact GO prepared by the method illustrated in Figure 2.23c, data relate to a density of defects of about 0.3% [12]. (b) Oxo-functionalized graphene derived from graphite sulfate, as illustrated in Figure 2.23d and the average density of defects can be related to about 0.05% [72].

Figure 2.25 Illustration of graphene derived structures ranging from molecules, such as benzene or hexabenzocorronene and even larger units, such as C

222

graphene like units. Structures are monodisperse with a diameter of up to 5 nm. Graphene nanoribbons of larger size and variable shape; graphene quantum dots (GQDs) with lateral dimensions between 10 and 100 nm and graphene of typically micrometer size crystals, at least >100 nm in both directions. (From Ref. [80] with permission from Wiley-VCH Verlag GmbH & Co, Copyright 2012.) The STM images of GQDs modified with permission from Ref. [81]. (Reprinted from Ref. [82] with permission from Nature Publishing Group, Copyright 2010.)

Figure 2.26 (a) Example of the synthesis of the C

222

graphene-like unit by the wet-chemical bottom-up approach. The reaction scheme shows a Diels–Alder reaction followed by cyclotrimerization that yields the soluble precursor molecule that can be oxidized in CS

2

to the depicted π-conjugated hydrocarbon [86]. (b) Synthetic bottom-up approach to graphene nanoribbons. Soluble precursors functionalized by halides and boronic esters are C–C coupled to define the nanoribbon structure. Oxidation of the preoriented benzene rings yields π-conjugated nanoribbons. (Modified from Ref. [87] with permission from the American Chemical Society, Copyright 2008.)

Figure 2.27 (a) Top: Chemical structure of a cyclohexaphane derivative as precursor for porous graphene (blue, illustrated on gray graphene structure). Bottom: Related high-resolution scanning probe microscope image. (From Ref. [80] with permission from Wiley-VCH Verlag GmbH & Co, Copyright 2012; modified from [88] with permission from the Royal Society of Chemistry. Copyright 2008; images reproduced from Ref. [89] with permission from the Royal Society of Chemistry, Copyright 2011).) (b) Left: Synthesis of chevron-type graphene nanoribbons by the polymerization of bis-brominated tetraphenyl triphenylene at 250 °C to a prepolymer followed by dehydrogenation at 440 °C. Right: Scanning probe microscope image visualizing the chevron-type structure. (c) Bottom-up synthesis of a junction using bis-activated and tris-activated precursor molecules and scanning probe microscopy image of the junction. (Reprinted from Ref. [82] with permission from the Nature Publishing Group, Copyright 2010.)

Chapter 3: Graphene Composites

Figure 3.1 Proposed reactions during the isocyanate treatment of GO, where organic isocyanates react with the hydroxyl (left oval) and carboxyl groups (right oval) of graphene oxide sheets to form carbamate and amide functionalities, respectively.

Figure 3.2 Schematic representation of functionalization and composite fabrication.

Figure 3.3 (A) XRD patterns of (a) pristine graphite, (b) graphite oxide, (c) graphene, (d) PP latex, and (e) PP-coated graphene. (B) XRD pattern of PP/graphene nanocomposites with various graphene loadings.

Figure 3.4 FTIR spectra of (a) graphite oxide, (b) DA-G, (c) LLDPE, and (d) LDG-3.

Figure 3.5 FESEM micrographs of (a) dritic and (b) rod like structured PVA/SG composites. (Reproduced from Ref. [109] with permission from Elsevier).

Figure 3.6 TEM image of DA-G/LLDPE composite. (Reproduced from Ref. [100] with permission of Elsevier.)

Figure 3.7 Typical stress–strain curves of (a) GO/PVA composites with varying GO loadings and (b) graphene/PVA composites with varying graphene loadings. (Reproduced from Ref. [113] with permission from John Wiley and Sons.

Figure 3.8 SEM images of (a) GO and (b) f-PVA-GO composites. The inset shows high resolution image.

Figure 3.9 Typical stress–strain, Young's modulus and elongation-at-break cure of PET composites with GO and f-GO.

Figure 3.10 (a) TEM images of GO, OAPS-GO at low and magnification. (b) Typical stress–strain curve of OAPS-GO/PI film at various loadings of OAPS.

Figure 3.11 (a) Stress–strain curves of TPU and TPU/HD-GNRs composite films. (b) Summary of tensile moduli of different samples.

Figure 3.12 Mechanical properties of composites with different filler loadings: (a) tensile strength, (b) tensile stress–strain curves, (c) compressive strength, (d) flexural strength and modulus.

Figure 3.13 (a) Schematic diagram of parallel and perpendicular tensile strength, as well as electrical and thermal conductivities of AG/E in parallel and perpendicular directions. (b) Temperature dependence of thermal conductivities in AG/E and DG/E. (c) Thermal conductivity as a function of temperature for AG/E for three heating cycles. (d) The effect of the alignment extent on theoretical thermal conductivity in AG/epoxy.

Figure 3.14 TEM images of graphene-epoxy resin composite (1.5 wt% of filler loadings) at (a) low and (b) high magnification.

Figure 3.15 TMA curves of (a) neat PI film and D400-GO/PI films and (b) neat PI film and D2000-GO/PI films.

Figure 3.16 TGA profile of (a) alkylated graphene oxide/polypropylene composites and (b) different carbon fillers/polypropylene composites.

Figure 3.17 Electrical conductivity of isocyanate treated graphene/PS composites. Inset Figure represents percolation threshold and set up for measurement.

Figure 3.18 Variation of electrical conductivity of PS composite against filler loadings.

Figure 3.19 (a) Electrical conductivity comparison of the graphene and carbon nanotube–polystyrene composites fabricated by solution mixing and electrostatic self-assembly methods. (b) Top view and (c–e) cross-sectional SEM images of the remaining graphene skeleton after annealing the testing samples at high temperature under nitrogen atmosphere.

Figure 3.20 (a) Dynamic tensile moduli of graphene polyimide nanocomposites at 50 (b) and 150 °C (2) as a function of graphene content. (b) Dynamic storage moduli of the polyimide nanocomposites containing graphene (9) and rigid imidized graphene (0) at 150

o

C.

Figure 3.21 Hydrogen bonding interaction between GO and NaCME.

Figure 3.22 Dynamic mechanical properties of cured epoxy composites containing: (a) and (c) poorly dispersed RGO; (b) and (d) highly dispersed RGO.

Figure 3.23 (a) Electrical conductivity versus rGO loading for the s-rGO/PS composites; (b) EMI SE as a function of frequency in X-band range for the composites; (c) typical stress–strain curves of the s-rGO/PS composites with 1.95 vol% rGO molded under high and conventional pressure; and (d) compressive strength and modulus of the s-rGO/PS composites. I and II indicate composites molded under conventional and high pressure, respectively.

Chapter 4: Graphene in Lithium-ion Batteries

Figure 4.1 Evolution of energy consumption by resource type [1].

Figure 4.2 Parthian battery.

Figure 4.3 Principles of lithium-ion battery operation.

Figure 4.4 Schematic structure of a lithium-ion battery.

Figure 4.5 Structure of graphite.

Figure 4.6 Battery grade graphite [11].

Figure 4.7 Graphene structure.

Figure 4.8 Different scenarios designed to improve anode performance.

Figure 4.9 Graphene-based materials in lithium-ion battery anodes.

Figure 4.10 Bonding in nitrogen-doped graphene.

Figure 4.11 Graphene/MO composite formation.

Figure 4.12 Structural mechanisms for compositing graphene with metal oxides for lithium battery applications.

Chapter 5: Graphene-Based Membranes for Separation Engineering

Figure 5.1 Processes to create controlled pores in a graphene membrane: (a–c) gallium ion bombardment of graphene sheets; (d) etching with oxidizing solution.

Figure 5.2 (a) Lerf–Klinowski structural model for GO showing carboxylic acid groups at the edges, and phenol hydroxyl and epoxide groups mainly at the basal planes. (Reproduced from Ref. [38] with permission from the American Chemical Society, Copyright 1998.) (b) 3D view of a GO sheet.

Figure 5.3 Microstructures of graphene-derived membranes: (a) The percolated water transport channel is composed of interlayer, interedge spaces, wrinkles, and pores within the graphene sheets. (b) The pristine and oxidized patterns on GO (left) are modeled in a quasi-2D molecular model (center) with oxygen-containing functionalized groups on both sides (right) (Reprinted from Ref. [42] with permission from the American Chemical Society, Copyright 2014). (c) Sketches of water motion through the stacked GO layers with channels (capillaries) in the vicinity of the edges of graphene sheets. The oxidized area is denoted by red color and graphene without oxidation by green. Solid (dotted) blue lines are (un)favorable paths for water permeation. All edges are assumed to be passivated by hydrophilic edge groups.

Figure 5.4 GO membranes. (a) Water and small-sized ions and molecules (compared with the void spacing between stacked GO nanosheets) permeate superfast in the GO membrane, but larger species are blocked. (b) The separation capability of the GO membrane is tunable by adjusting the nanochannel size.

Figure 5.5 (a) Photo of a 1-mm-thick GO film peeled off of a Cu foil. (b) TEM of the film cross-section (c) mounted on Cu hole for separation test.

Figure 5.6 Schematic illustration of (a) an LbL procedure to synthesize the GO membrane; (b) the mechanism of reactions between polydopamine and TMC, and (c) the mechanism of reactions between GO and TMC.

Figure 5.7 Comparison of gas permeation rates of pristine and porous graphene membranes: (a) maximum deflection of the membrane surface versus time before and after etching; (b) gas permeance versus molecular size, revealing selective permeation of H

2

and CO

2

over larger gas molecules after etching. The connecting lines show the measurements before (black) and after (red) etching.

Figure 5.8 Permeation of gas molecules through laminates of GO membranes. (a) Permeation of gases through defect regions. (b) Performance of GO membranes relative to other high-performance polymeric (TR, thermally rearranged polymer; TZPIM, tetrazole functional polymer of intrinsic microporosity; PIM, polymer of intrinsic microporosity) and inorganic (CMS, carbon molecular sieve, zeolite, silica) membranes.

Figure 5.9 Permeation through GO membrane. (a) Weight loss for a container sealed with a GO film. No loss was detected for ethanol, hexane, and so on, but water evaporated from the container as freely as through an open aperture (blue curves). (b) Permeability of GO membrane with respect to water and various small molecules (arrows indicate the upper limits set by our experiments). (Inset) Schematic representation of the structure of monolayer water inside a graphene capillary with

d

= 7 Å.

Figure 5.10 Schematic diagrams of a GO membrane and the interaction with different ions.

Figure 5.11 (a) Ion permeation through GO laminates. Permeation through a 5-mm-thick GO membrane from the feed compartment with a 0.2 M solution of MgCl

2

. (Inset) Permeation rates as a function of C in the feed solution; (b) Sieving through atomic-scale mesh. The shown permeation rates are normalized per 1 M feed solution and are measured by using 5-mm-thick membranes.

Figure 5.12 Schematic illustration of a multilayered GO coating on a PA thin-film composite membrane surface via LbL deposition of oppositely charged GO and aminated-GO (AGO) nanosheets.

Figure 5.13 Cross-sectional M-GO/GOT SEM images at different magnifications. (a) 1000×; (b) 2500× (inset corresponds to the freestanding GO membrane: M-GO).

Chapter 6: Graphene Coatings for the Corrosion Protection of Base Metals

Figure 6.1 Schematic depiction of different modes of corrosion inhibition, including barrier protection, cathodic protection, anodic passivation, active corrosion inhibition, and “self-healing” [9].

Figure 6.2 Schematic depiction of the four main modes of corrosion inhibition by graphene. This graphic depicts the ways by which graphene can help to impede or entirely shut down the electrochemical processes related to corrosion: by providing barrier protection; by requiring a tortuous path for ion permeation; by formation of a potential barrier at the graphene/metal interface (either a Schottky barrier or interfacial dipole); and by providing an alternative electronic pathway.

Figure 6.3 Schematic depiction and overview of selected polymers that graphene has been incorporated in for use as a corrosion-resistant coating.

Figure 6.4 Tafel plot showing enhanced corrosion resistance afforded by the 20 wt% UFG/PEI coating as compared to a PEI coating and uncoated low-alloy steel.

Figure 6.5 Digital photographs of salt-water immersion measurements on uncoated low-alloy steel, a PEI coating, and a 20 wt% UFG/PEI coating [37].

Chapter 7: Graphene Market Review

Figure 7.1 The price of graphene.

Figure 7.2 Stock value of some publicly traded graphene companies

Figure 7.3 Haydale stock price.

Figure 7.4 Graphene industry diagram, highlighting key businesses.

Figure 7.5 Time to market and technology readiness level of some applications (author's own predictions).

List of Tables

Chapter 1: Graphene Technology: The Nanomaterials Road Ahead

Table 1.1 NanoXplore graphene improves polymer thermal conductivity and effusivity

Table 1.2 NanoXplore graphene improves polymer mechanical properties

Chapter 4: Graphene in Lithium-ion Batteries

Table 4.1 The availability of fuels [2]

Table 4.2 Evolution of batteries

Table 4.3 Common materials used in lithium-ion batteries

Table 4.4 Selected properties of graphene.

Chapter 6: Graphene Coatings for the Corrosion Protection of Base Metals

Table 6.1 Corrosion potential (

E

corr

), corrosion current density (

I

corr

), and extrapolated corrosion rate in mm yr

−1

from electrochemical testing of low-alloy steel, PEI coating, and 20 wt% UFG/PEI coating

Table 6.2 Average grain size calculated using the Scherrer equation and the reduction in grain size upon incorporation of graphene [74–77]

Table 6.3 Summary of Tafel analysis results for Ni/graphene, Zn/graphene, and Sn/graphene composite coatings [74–77]

Edited by Soroush Nazarpour and Stephen R. Waite

Graphene Technology

From Laboratory to Fabrication

Editors

Dr. Soroush Nazarpour

Group NanoXplore Inc.

25 Montpellier Blvd

Montreal

QC H4N 3K7

Canada

Stephen R. Waite

Graphene Stakeholders Association

640 Ellicott Street, Suite 499

Buffalo

NY 14203

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List of Contributors

Sarbajit Banerjee

Texas A&M University

Department of Chemistry

College Station

TX 77842-3012

USA

and

Texas A&M University

Department of Materials Science and Engineering

575 Ross Street

College Station

TX 77843-3003

USA

Suman Chhetri

Surface Engineering & Tribology Division

Council of Scientific and Industrial Research-Central Mechanical Engineering Research Institute

Durgapur 713209

India

and

Academy of Scientific and Innovative Research (AcSIR)

CSIR-CMERI, Campus

Durgapur 713209

India

Rachel D. Davidson

Texas A&M University

Department of Chemistry

580 Ross Street

College Station

TX 77842-3012

USA

and

Texas A&M University

Department of Materials Science and Engineering

575 Ross Street

College Station

TX 77843-3003

USA

Robert V. Dennis

Texas A&M University

Department of Chemistry

580 Ross Street

College Station

TX 77842-3012

USA

and

Texas A&M University

Department of Materials Science and Engineering

575 Ross Street

College Station

TX 77843-3003

USA

Siegfried Eigler

Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU)

Central Institute of Materials and Processes and

Department of Chemistry and Pharmacy

Dr.-Mack-Str. 81

D-90762 Fürth

Germany

and

Chalmers University of Technology

Department of Chemistry and Chemical Engineering

Kemivägen 10

SE-412 96 Göteborg

Sweden

José L. Figueiredo

Laboratory of Separation and Reaction Engineering Laboratory of Catalysis and Materials (LSRE-LCM)

Chemical Engineering Department

Faculdade de Engenharia

Universidade do Porto

Rua Dr. Roberto Frias

4200-465 Porto

Portugal

Nathan A. Fleer

Texas A&M University

Department of Chemistry

580 Ross Street

College Station

TX 77842-3012

USA

and

Texas A&M University

Department of Materials Science and Engineering

575 Ross Street

College Station

TX 77843-3003

USA

Tapas Kuila

Surface Engineering & Tribology Division

Council of Scientific and Industrial Research-Central Mechanical Engineering Research Institute

Durgapur 713209

India

and

Academy of Scientific and Innovative Research (AcSIR)

CSIR-CMERI, Campus

Durgapur 713209

India

Sergio Morales-Torres

Laboratory of Separation and Reaction Engineering Laboratory of Catalysis and Materials (LSRE-LCM)

Chemical Engineering Department

Faculdade de Engenharia

Universidade do Porto

Rua Dr. Roberto Frias

4200-465 Porto

Portugal

Naresh Chandra Murmu

Surface Engineering & Tribology Division

Council of Scientific and Industrial Research-Central Mechanical Engineering Research Institute

Durgapur 713209

India

and

Academy of Scientific and Innovative Research (AcSIR)

CSIR-CMERI, Campus

Durgapur 713209

India

Soroush Nazarpour

Group NanoXplore Inc.

25 Montpellier Blvd

Montreal

QC H4N 3K7

Canada

Luisa M. Pastrana-Martínez

Laboratory of Separation and Reaction Engineering Laboratory of Catalysis and Materials (LSRE-LCM)

Chemical Engineering Department

Faculdade de Engenharia

Universidade do Porto

Rua Dr. Roberto Frias

4200-465 Porto

Portugal

Adrián M.T. Silva

Laboratory of Separation and Reaction Engineering Laboratory of Catalysis and Materials (LSRE-LCM)

Chemical Engineering Department

Faculdade de Engenharia

Universidade do Porto

Rua Dr. Roberto Frias

4200-465 Porto

Portugal

Marko Spasenovic

Graphene Tracker

Center for Solid State Physics and New Materials

Institute of Physics

Pregrevica 118

11030 Belgrad

Serbia

Stephen R. Waite

Graphene Stakeholders Association

640 Ellicott Street, Suite 499

Buffalo

New York 14203

USA

Cyrus Zamani

University of Tehran

School of Metallurgy and Materials Engineering

College of Engineering

University of Tehran

North Kargar Street

P. O. Box 14395-515

Tehran

Iran

Chapter 1Graphene Technology: The Nanomaterials Road Ahead

Stephen R. Waite and Soroush Nazarpour

A new paradigm is emerging for advanced nanomaterials and their use in commercial products. We call it “molecular precision manufacturing” (MPM), and it is evolving as a consequence of the need to develop new tools, new standards, new protocols, and new processes (TSPPs) to foster the commercialization of nanomaterials.

Nanomaterials possess extraordinary properties, but harnessing these properties for use in commercial products is challenging. The emerging MPM paradigm is required in order to realize the tremendous commercial potential of advanced nanomaterials – both 2D and 3D – discovered over the past 25 years.

The TSPPs associated with MPM have been in development for several decades. They combine activities that are critical to the use of advanced nanomaterials in products and applications: 2D materials, such as graphene, molybdenum disulfide, and boron nitride; and 3D nanomaterials, such as single-wall and multi-wall carbon nanotubes (CNTs). Additionally, technologies have been developed to functionalize these advanced 2D and 3D nanomaterials to enhance their properties for use in commercial products. We are at an early stage in the evolution of functionalized advanced 2D and 3D nanomaterials, but the research done thus far is encouraging.

1.1 Newly Discovered 2D Materials

The past decade has witnessed the discovery of several 2D nanomaterials, all of which possess unique properties suited to various applications. These discoveries include the following:

Graphene: Single layer of carbon atoms only 1 molecule thick packed in a hexagonal lattice.

Molybdenum disulfide (MoS2): When stacked, MoS2 looks and feels like graphite. However, it is very different from graphene at the 2D level. While graphene is a flat layer of carbon atoms, MoS2 is composed of molybdenum atoms sandwiched between two sulfur atoms. Unlike graphene, in its natural form it can serve as a semiconductor in transistors, making it appealing for use in electronics and solar cells. Scientists have been experimenting with combining the two materials to allow graphene to have transistor-friendly properties, but are now looking at using MoS2 on its own. It has properties similar to silicon, but requires the use of much less material and consumes less energy.

Silicene: When silicon is reduced to a 1-atom-thick layer, it takes on a slightly squished-looking honeycomb structure similar to graphene. Like molybdenum disulfide, it can be used as a transistor in its natural form. Silicene also shares one of graphene's especially interesting properties: electrons move through it at a very fast pace, as if they were massless. This means that silicene conducts electricity faster than any commercially available semiconductor. Because silicon is so ubiquitous in current electronics, silicene could be much easier to adopt than other 2D materials. It was only recently synthesized for the first time last year, so the research will take some time to mature. It also could turn out to be more difficult to make than graphene.

Germanane: The element germanium has already been used as a semiconductor, and actually formed the very first transistors in the 1940s. When reduced to a single layer of atoms, it forms a material known as germanane. Germanane conducts electrons 5 times faster than germanium and 10 times faster than silicon, which makes it ideal for creating faster computer chips. It is more stable than silicon and a better absorber and emitter of light. Manufacturers may also be able to produce it on existing equipment in large quantities, which would give it an advantage over emerging graphene manufacturing techniques.

Our experience of working with 2D nanomaterials is limited, given their relatively recent discovery – in the case of graphene, as recent as 2004. Working with 2D materials presents a set of learning curves that require scaling even before the potential of such promising materials can be realized. The TSPPs associated with the emerging MPM paradigm are critical to the commercialization of products and applications using 2D nanomaterials and their 3D counterparts.

Commercialization demands that one has a consistent and repeatable product available at a rational price, given the performance impact and value proposition. Creating the strongest composite in the world is of no value if its mechanical properties cannot be predicted or relied upon because of inconsistent materials or testing. Without these TSPPs, we are not likely to see the fruits anticipated with nanotechnology that many analysts have envisioned, given its vast potential in commercial applications.

In the following text, we offer an overview of MPM and shed light on the promises and challenges associated with the emerging MPM paradigm.

1.2 Wonder Materials

The ascent of MPM is associated with the discovery of “bulk” nanomaterials possessing remarkable properties. We make the distinction between bulk materials and nanoscale elements of electronic and semiconductor devices, for example, which are created as sub-micron architectures using processes such as chemical vapor deposition and epitaxial growth, but which are not “freestanding” materials.

One of the early nanomaterial discoveries came from Rice University in the mid 1980s, with the synthesis of fullerenes, commonly referred to as buckyballs – hollow, spherical carbon structures that became an early impetus to research in novel carbon allotropes. The discovery led to more investigation in Japan on hollow tubes of carbon in the early 1990s and ignited great interest in single- and multi-wall CNTs. CNTs were seen to have a host of remarkable properties that stimulated the interest of nanotechnology researchers all over the world, and it was not long before patent filings on CNT-based applications began to skyrocket.

In 2004, researchers Andre Geim and Kostantin Novoselov from the University of Manchester discovered graphene – another nanomaterial possessing truly extraordinary properties. In 2010, Geim and Novoselov were awarded the Nobel Prize in Physics for their discovery of this “wonder material,” which comprises a single layer of carbon atoms only 1 molecule thick (hence its 2D classification) and packed in a hexagonal lattice. It is the thinnest material known to man, with an exceptionally high theoretical surface area (2630 m2 g−1). Atomically, it is the strongest material ever measured, is extremely elastic (stretchable), and has exceptional thermal and electrical conductivity, making it the substance a design engineer's dreams.

Understandably, graphene-related patent filings have risen significantly around the world over the past several years. The United Kingdom is currently a hotbed of activity in graphene, with the University of Manchester acting as a magnet for millions of dollars of research funding. In 2013, the European Union created a Flagship to promote the development of graphene, committing 1 billion Euros in funding over a 10-year time frame. Entrepreneurial activity and investment associated with graphene has increased significantly. Technology stalwarts Samsung and IBM have been extremely active in patenting graphene-based applications. The Far East has been massively active not only in patent applications, but also in investment. Singapore, for example, boasts the highest level of graphene research funding as a percentage of GDP in the world.

With the discovery of graphene in 2004, we have entered a new age of materials and materials science. Since then, several other 1-atom or 1-molecule-thick crystals have been isolated and tentatively studied. These materials range from semiconducting monolayers to wide-gap insulators to metals. This growing library of 2D materials opens the potential to construct various 3D structures with on-demand properties that do not occur naturally, but can be assembled “Lego-style” by stacking individual atomic planes on top of one another in a desired sequence (see Section 1.1).

The discovery of new advanced nanomaterials – both 2D and 3D – over the past 25 years has generated much excitement and hype, which is understandable in light of their remarkable properties. Today, the range of potential applications for graphene and other 2D materials is limited only by one's imagination. Yet, this potential needs to be tempered by the kind of level-headedness that comes from experience working with advanced nanomaterials.

In May 2013, Bayer Material Science (BMS) exited the CNT business and shuttered its production plant, after many years of work and millions' worth of investment. BMS CEO Patrick Thomas noted that while the company remains convinced that CNTs have huge potential (they initially talked of over 3000 tons of output), their experience suggests that potential areas of application that once seemed promising from a technical standpoint are currently either extremely fragmented or do not overlap with the company's core products and spectrum of applications.

At the time of exiting the business, it was reported that BMS had invested some $30 million to produce multi-walled CNTs with a facility that had a capacity of producing over 200 tons per year. Mitsubishi Corp. had a similar experience in the 1990s when it attempted to scale and commercialize fullerenes. While no public information has been made available, insiders indicated that as much as $60 million was invested and, to date, no commercial products realized.

While sobering, the BMS experience holds many valuable lessons for those seeking to commercialize advanced nanomaterials. The commercialization of advanced nanomaterials, and nanotechnology in general, is unlike anything ever undertaken before. Successful commercialization of these advanced nanomaterials requires new approaches, tools, and processes, and a great deal of what seems to be in short supply these days with investors: patience. Often, to satisfy the demands of investors, substantial claims are made on production volumes and estimated sales prior to evaluating the market and without exercising caution.

Arriving at a pure material virtually free from the catalysts used in the production process was not as easy as expected. The challenge was compounded by the need to functionalize these materials; to aid dispersion, acids were often used (as that was all that was available then). High levels of functionalization required a vicious circle of excessive acid treatment, with higher resultant costs, waste streams, and structural degradation.

Crucially, the effect of nanomaterials on the target medium is often not known or precisely predicted until it is attempted. Experience shows that taking a process from the lab (micro) level to the commercialization (macro) level is not easy, and in scaling up, the results can often be different from the lab-based results. This will affect commercial outcomes, possibly rendering a positive projected return to an uneconomic position. It is here that we encounter the classic case of over-promising and under-delivery, effectively stunting the market.

Having to learn these important lessons the hard way is common in business – through failed multimillion-dollar investments, layoffs, plant sales, and closure. Yet, it would be foolhardy to extrapolate failures associated with the development of CNTs into the future, for the very success with advanced nanomaterials lies in these failures. Thomas Edison, Nikola Tesla, and Steve Jobs are just a few famous examples of innovators whose failures led to successes beyond their wildest dreams. Fostering a culture of acceptance of failure as a learning process that moves one closer to success is crucial. How often is a failure seen as unacceptable, resulting in management changes that may not be justified?

Failure is instructive, and a large part of the innovation process. That said, it is important to respect the meme that insanity is doing the same thing over and over and expecting different results, as Einstein once observed. What we learn from the failures of working with advanced nanomaterials is that traditional approaches and processes do not work, and something else is required. This is where MPM comes in.

1.3 The Rise of MPM

Humans have been figuring out how to turn various materials into useful products since the Stone Age. While some of this knowledge scales into the commercialization of nanomaterials today, new learning curves are clearly required to bring advanced nanomaterials to the market in the form of new products and applications.

The BMS experience over the past decade with CNTs is a clear example. Nobody disputes the theoretical properties of advanced nanomaterials such as CNTs and graphene. These are well known. As Andrew Geim recently put it: Graphene is dead. Long live graphene! Hundreds of peer-reviewed scientific papers have been published on the properties of graphene and other nanomaterials. The major issue associated with these materials is not theory and properties, but practice and application. How do we turn their fantastic properties into useful and, in some cases, game-changing products?

It is clear from the experience of BMS and others that traditional approaches to commercializing these materials are not effective. The emergence of MPM is due to the shortcomings of these traditional approaches. We know that growth is a function of learning. After all, the cave man had access to all of the materials we have today. What the cave man did not have was the propensity for learning that comes from having experienced failure and success. MPM embraces the learning curves associated with bringing advanced nanomaterials to the market through the development of new processes, standards, tools, and technologies.

There is no reason a priori to expect the earlier-described TSPPs associated with the successful commercialization of non-nanomaterials to be the same for nanomaterials. It is natural to want to apply the same tried-and-true TSPPs to commercialize advanced nanomaterials. At the heart of MPM is the development of new TSPPs necessary for the proper characterization and functionalization of advanced 2D and 3D nanomaterials, together with its effect on the target matrix and down-stream processing.

“Characterization” of nanomaterials is critical. Characterization involves the use of sophisticated metrology tools and information technology that peer down into the nano world and generate data that help us identify the type of nanomaterial being developed for commercialization. Manufacturers today might believe they are working with graphene because their supplier told them it was graphene, when in truth, characterization identifies the material as akin to “soot.” And there is a world of difference between graphene and soot. Knowing the kind of material one is using is paramount to the commercialization process. The way to know what type of material is being used is via characterization analysis. Characterization analysis enables material comparison and is a key component – and the foundation – of the MPM paradigm.

A great deal of work is being done today by researchers at the National Physical Laboratory (NPL) in the United Kingdom and elsewhere that is pushing the envelope of characterization analysis. NPL and others are pioneering new techniques that allow for more accurate assessment of nanomaterials, and even tools to enable real-time characterization of graphene. New types of metrology tools are being developed to foster characterization analysis of newly discovered 2D nanomaterials.

Researchers at Lancaster University (LU) note that scanning probe microscopy (SPM) represents a powerful tool which, in the past three decades, has allowed researchers to investigate material surfaces in unprecedented ways at the nanoscale level. However, SPM has shown very little power of penetration, whereas several nanotechnology applications would require it. The LU researchers are using other tools, such as ultrasonic force microscopy (UFM), in work with graphene and other 2D materials, including MoS2. UFM is a variation of the atomic force microscope (AFM) that overcomes the limitations of SPM in characterizing advanced nanomaterials such as graphene and other 2D materials.

These new tools and techniques in development will give manufacturers the important data necessary to ensure that the correct material is being used in the manufacturing process. They also promise to foster quality control in a manner that has not existed previously. As producers in any industry know, quality control is paramount to successful commercialization. Additionally, the creation of sophisticated models to assist in the development, design, and integration of these materials into devices and products relies heavily on the completeness and reliability of property data for these nanomaterials.

Characterization work also facilitates the development of standards that are critical to the evolution of advanced nanomaterials. The term graphene today covers a family of different materials, including several-layer flakes, powders, liquid dispersions, and graphene oxide. Importantly, the corresponding properties and potential applications will vary depending on the type of material used.

The other critical part of MPM is dispersion. The ability to consistently and uniformly disperse graphene in another material is important to realizing the outstanding properties of the material. Functionalizing graphene properly can enhance the strength, stiffness, and conductivity of the resulting composites, depending on the requirements and applications being targeted.

1.4 Addressing the Environment, Health, and Safety

Another important component of the emerging MPM paradigm relates to the environmental, health, and safety (EH&S) procedures and protocols for advanced nanomaterials. There have been a number of “scare stories” in the media about the potential toxicity of various nanomaterials. Most of these fail to consider the final product form that nanomaterials actually take when introduced to the market, as well as the potential, or lack thereof, of their release into the environment as nano-sized particles.

Without a clear understanding of the full manufacturing cycle, product form, and disposal considerations, the limited information generated by current studies is of little relevance. Additionally, lacking test standards and precise definitions, it is impossible to conduct credible, repeatable, and scientifically valid studies. All of the characterization work that is going on behind the scenes with graphene and other 2D materials today is important to future EH&S studies.

It is incumbent upon all in the nanomaterials community to collaborate on EH&S-related issues. The new characterization tools and techniques that have been developed and are being developed will help facilitate toxicity studies. There are groups of researchers today, such as the Arkansas Research Alliance, that are intent on doing credible nontoxicity research on graphene and other nanomaterials that can be of benefit to all who wish to promote the responsible development of such materials.

One way to minimize the EH&S effect and aid commercialization is to add the nanomaterials to a carrier in the form of a loaded masterbatch, which is then let down (diluted) by a processor with the raw, untreated carrier material. This offers controllability; and once in a masterbatch, it can be handled without the need for expensive nano-handling environments.

1.5 The Nanomaterials Road Ahead

We are still at an early stage with the new MPM paradigm. The promise of nanomaterials such as graphene and CNTs is great, but so, too, are the challenges associated with successful commercialization. Several of the key challenges associated with commercializing nanomaterials-enabled products are being addressed through the development of the MPM paradigm. Again, considerable progress has been made, but there is much more work to be done in terms of testing and data analysis.

Companies seeking to work with graphene and other nanomaterials need to know the type of materials they are using. Characterization analysis provides this information and also helps to facilitate standards that are necessary for industry maturity and EH&S-related research. Additionally, companies need ways of reliably producing materials to achieve their desired properties. Functionalization assists greatly in this area, for without it, the inert carbon-based material will not want to disperse readily into a target medium. With respect to functionalization, it is also early days, but we see a great deal of potential as functionalization becomes commonplace among those commercializing advanced nanomaterials. It is clear from the lack of progress with CNTs thus far that there is a need for a paradigm such as MPM if we are going to realize the promise and potential of graphene and other nanomaterials.

The excitement over these newly discovered nanomaterials is warranted, but again, those seeking to invest and innovate in this promising area need be mindful of the challenges associated with commercializing these materials. Key to progress on the commercialization front is close collaboration among suppliers and producers and a good deal of patience among all participants involved: the history of materials tells us that it can take years, and sometimes decades, before a new “wonder material” fulfills its promise and potential.

Consider the evolution of materials such as aluminum and advanced ceramics. Aluminum was discovered in a lab in the 1820s. Like CNTs and graphene, the material was hailed as a wonder substance, with qualities never seen before in a metal. However, it proved expensive to make, and it was not until many decades later that it took off in the marketplace, when a new process using electricity was invented.

Similarly, many of us remember the excitement surrounding advanced ceramics in the early 1980s, and the fever that developed with the discovery of high-temperature ceramic superconductors. The promise of ceramic engines, loss-free electrical transmission lines, and many other products that these material advances were expected to enable has remained unfulfilled. That said, the impact that these materials have had on our lives is nearly impossible to list – ranging from the mundane to the exotic and impacting transportation, communications, electronics, consumer goods, medical devices, and energy in ways that may be hidden but are enabling nonetheless.