SYNTHESIS AND CHARACTERIZATION OF SYNTHESIS AND CHARACTERIZATION OF - - PowerPoint PPT Presentation

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SYNTHESIS AND CHARACTERIZATION OF SYNTHESIS AND CHARACTERIZATION OF GRAPHENE OXIDE DERIVATIVES VIA FUNCTIONALIZATION REACTION WITH HEXAMETHYLENE DIISOCYANATE HEXAMETHYLENE DIISOCYANATE 1 G 2 C Jos A. Luceo Snchez 1 , Georgiana Maties 2 ,

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SYNTHESIS AND CHARACTERIZATION OF SYNTHESIS AND CHARACTERIZATION OF GRAPHENE OXIDE DERIVATIVES VIA FUNCTIONALIZATION REACTION WITH HEXAMETHYLENE DIISOCYANATE HEXAMETHYLENE DIISOCYANATE

J é A L ñ Sá h

1 G

i M ti

2 C

i José A. Luceño‐Sánchez1, Georgiana Maties2, Camino González‐Arellano2, Ana M. Díez‐Pascual1

1Department of Analytical Chemistry, Physical Chemistry

and Chemical Engineering and Chemical Engineering

2Department of Organic Chemistry and Inorganic Chemistry

University of Alcalá, 28871, Madrid, Spain

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OUTLINE OUTLINE

1 I d i 1. Introduction 1.1 Graphene and properties 1 2 Graphene Oxide and properties 1.2 Graphene Oxide and properties 1.3 G and GO applications 2 Functionalization reaction 2. Functionalization reaction 3. Experimental procedure 3.1 Synthesis of GO 3.1 Synthesis of GO 3.2 Functionalization of GO 3.3 Characterization of HDI‐functionalized GO 4. Results and Discussion 5. Conclusions

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1 INTRODUCTION

  • 1. INTRODUCTION
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1 1 Graphene and properties 1.1 Graphene and properties

  • Graphene (G) is an allotrope of carbon like

diamond:

2D t i ll thi k 2D atomically thick single layer

  • f

sp2 carbon atoms carbon atoms

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1 1 Graphene and properties 1.1 Graphene and properties

  • Properties of G:
  • 2D atomically thick single layer of sp2 carbon atoms.
  • Outstanding electrical conductivity (higher than Cu) and

high electron mobility.

  • Great thermal conductivity (higher than Cu).
  • One of the strongest materials on Earth.
  • Low light absorption (aprox. 2,3%).
  • Insoluble in water.
  • No fluorescence.

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1 2 Graphene Oxide and properties 1.2 Graphene Oxide and properties

  • Graphene Oxide (GO) is the oxidated form of

G:

O

OH

HO

O HOOC

Functional

COOH

O HO O

HOOC OH O

Functional groups are arbitrarily

COOH OH O HO HO

located and randomly aggregated

COOH HOOC OH

aggregated

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1 2 Graphene Oxide and properties 1.2 Graphene Oxide and properties

  • Properties of GO (I):
  • Contains epoxy, hydroxyl and carbonyl groups on the

basal plane, and carboxylic groups on the edges.

  • Higher interlayer spacing than G, due to sp3 carbons.
  • Higher ability to retain compounds.
  • Lower electron mobility.
  • Soluble in water.
  • Amphiphilicity.
  • Surface‐functionalization capability and versatility.

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1 2 Graphene Oxide and properties 1.2 Graphene Oxide and properties

  • Properties of GO (II):
  • Biocompatibility and able to interact with biological

cells and tissues. Important on large‐scale processing

  • Highly hydrophilic, forming stable aqueous colloids.
  • Substrate‐deposition capability.

Great potential for electronic

  • Convertible into a conductor.

application

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1 3 G and GO applications 1.3 G and GO applications

G AND GO

MEDICINE HIGH PERFORMANCE COMPOSITES

POSSIBLE APPLICATIONS

SOLAR CELLS

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2 FUNCTIONALIZATION REACTION

  • 2. FUNCTIONALIZATION REACTION
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2 Functionalization reaction

  • 2. Functionalization reaction

OH HOOC

  • Reason to use GO inside pristine G:

COOH

O HO O

HOOC OH O OH O HO HO COOH HOOC OH

Possible functionalization points: ‐ Hidroxyl group ‐ Epoxy group ‐ Carboxylic group

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2 Functionalization reaction

  • 2. Functionalization reaction

Result: HDI HDI‐func GO HDI (crosslinking)

Reactants Catalyst

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3 EXPERIMENTAL PROCEDURE

  • 3. EXPERIMENTAL PROCEDURE
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3 1 Synthesis of GO 3.1 Synthesis of GO

’ h

  • Hummer’s method:

1. Heating of G powder during 5h at 80⁰C (with H2SO4, K2S2O8 and P2O5). and P2O5). 2. Stirring of previous mixture overnight (with deionized H2O). 3. Filtration and drying of mixture. 4. Oxidation with strong acids (H2SO4, KMnO4) and water in ice‐ water bath. i f O i h O d Cl 5. Decomposing of excess KMnO4 with H2O2 and HCl. 6. Recovery of GO (1. centrifugation and removal of the liquid;

  • 2. addition of aqueous solution of H2SO4/H2O2; 3. bath ultra‐
  • 2. addition of aqueous solution of H2SO4/H2O2; 3. bath ultra

sonication 30min; 4. washing with deionized water; and 5. vacuum freeze‐dried).

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3 2 Functionalization of GO 3.2 Functionalization of GO

  • 1. Adding Toluene to GO:

 Use of spherical bottom flask p with two mouths

  • 2. Ultrasonication:

 2h in ultrasonication bath 15

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3 2 Functionalization of GO 3.2 Functionalization of GO

  • 3. Adding triehylamine (TEA).
  • 4. Adding hexamethylene
  • 4. Adding hexamethylene

diisocyanate (HDI).  Instrument employed: p y

 Dropping funnel  Dropwisely  Dropwisely 16

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3 2 Functionalization of GO 3.2 Functionalization of GO

i

  • 5. Reaction:

 60 ⁰C overnight.  Stirred under an inert atmosphere of argon.

  • 6. Recover the product:

 Coagulate with dichloromethane (CH2Cl2).  Filtration and washing with CH2Cl2.

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4 RESULTS AND DISCUSSION

  • 4. RESULTS AND DISCUSSION
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4 Results and Discussion

  • 4. Results and Discussion

GO/HDI/TEA REACTION REACTION / / Sonication S l GO/HDI/TEA ratio REACTION TIME REACTION TEMPERATURE G/HDI/TEA ratio %C O% %H %N %S FD* Sonication time Solvent volume (ml) GO ‐ ‐ ‐ 41.93 51.96 3.44 2.67 ‐ ‐ GO‐HDI 1 12 60 1/1/1 53.08 35.70 4.22 6.02 0.98 12.28 2 h 25 GO‐HDI 2 12 60 0,5/1/1 47.38 44.75 3.83 2.49 1.55 5.08 2 h 25 GO‐HDI 3 48 60 1/1/1 50.36 40.16 4.01 4.46 1.01 9.10 2 h 25 GO 3 8 60 / / 50 36 0 6 6 9 0 5 GO‐HDI 4 12 90 1/1/1 45.98 46.97 3.67 1.53 1.85 3.12 2 h 25 GO‐HDI 5 12 60 1/1/1 55.49 31.07 4.50 8.43 0.51 17.20 5 min + 2 h 50

* h h f f b h h f h h d f h h d l

GO‐HDI 6 12 60 1/1/1 56.04 30.09 4.55 8.88 0.44 18.13 5+5+5 min + 2 h 50

*Assuming that the formation of carbamate esters through reaction of HDI with the OH or epoxide groups of GO is the hydroxyls

  • r epoxies is the unique reaction pathway, the nitrogen‐to‐carbon atomic ratio can be used to roughly estimate the

functionalization degree (FD), expressed as moles of carbamate ester unit incorporated per mol of carbon atoms of GO.

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4 Results and Discussion

  • 4. Results and Discussion

nce nsmittan Tran

G O G O -H D I 2 G O -H D I 4 G O -H D I 6 G O -H D I 1 G O -H D I 3 G O -H D I 5

4000 3500 3000 2500 2000 1500 1000 500

W avenum ber (cm

  • 1)

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5 CONCLUSIONS

  • 5. CONCLUSIONS
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5 Conclusions

  • 5. Conclusions
  • Hexamethylene diisocyante‐functionalized graphene oxide (HDI‐

GO) samples with different functionalization degree have been GO) samples with different functionalization degree have been prepared following a simple two‐step approach.

  • The FT‐IR spectra corroborate the successful synthesis of the HDI‐

p y GO samples and that the functionalization route via carbamate ester formation predominated.

  • Further characterization of HDI‐GO by Transmission electron

microscopy (TEM), Raman spectroscopy, water contact angle and thermogravimetric analysis (TGA) will be carried out. thermogravimetric analysis (TGA) will be carried out.

  • The HDI‐GO could further react with other organic molecules or

polymers via the remaining oxygen groups, which makes them ideal candidates as nanofillers for high‐performance GO‐based polymer nanocomposites

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THANK YOU FOR YOUR ATTENTION THANK YOU FOR YOUR ATTENTION