dispersion and alignment of carbon nanotubes in polymer based composites

221 Pages·2007·5.2 MB·English

DISPERSION AND ALIGNMENT OF CARBON NANOTUBES IN
POLYMER BASED COMPOSITES

A Dissertation
Presented to
The Academic Faculty

by

Erin Lynn Camponeschi

In Partial Fulfillment
of the Requirements for the Degree
Doctor of Philosophy in the
School of Materials Science and Engineering

Georgia Institute of Technology
DECEMBER 2007

COPYRIGHT 2007 BY ERIN LYNN CAMPONESCHI
DISPERSION AND ALIGNMENT OF CARBON NANOTUBES IN
POLYMER BASED COMPOSITES

Approved by:

Dr. Rina Tannenbaum, Advisor Dr. Hamid Garmestani, Advisor
School of Materials Science and School of Materials Science and
Engineering Engineering
Georgia Institute of Technology Georgia Institute of Technology

Dr. Ken Gall Dr. Meisha Shofner
School of Materials Science and School of Polymer, Textile, and Fiber
Engineering Engineering
Georgia Institute of Technology Georgia Institute of Technology

Dr. Thomas Sanders
School of Materials Science and
Engineering
Georgia Institute of Technology

Date Approved: July 23, 2007
For my family and friends
ACKNOWLEDGEMENTS

I would first like to thank my parents for supporting my decisions and supporting
me while I attained by goals. My advisors, Dr. Rina Tannenbaum and Dr. Hamid
Garmestani, have also guided me through my graduate work and helped mold me into the
researcher I am today. My thesis committee, Dr. Meisha Shofner, Dr. Ken Gall, and Dr.
Thomas Sanders, has also given me lots of support and assistance.
This work could not have been completed without the help of my research group
members, past and present: Melissa Williams, Jeremy Walker, Kasi David, Dan Ciprari,
Cantwell Carson, and Lex Nunnery. I would like to thank all of the friends who’ve come
and gone throughout my years here at Georgia Tech: Beth, Anne, Ven, Morgan, Matt,
Kip, Dan, Laura A., Laura C., Terra, Stef, Rob, Scott, Pete, Jelila, Liz, Laura D., Heather,
Chris, and especially Brett. And last but not least, are the wonderful MSE office staff
who’ve helped me navigate classes, registration, and finally graduation: Susan, Karen,
Jyoti, Mechelle, Renita, Shirely, and Jasmin.
I would also like to acknowledge the funding that allowed my research to be
continued these four years here at Georgia Tech. This work was supported by Institute of
Paper Science and Technology at Georgia Tech through the Otto Kress Scholarship,
without their generosity and support I would not be where I am today.

iv
TABLE OF CONTENTS
Page
ACKNOWLEDGEMENTS iv
LIST OF TABLES x
LIST OF FIGURES xi
SUMMARY xix
CHAPTER
1 Introduction 1
2 Background 4
2.1 Overview 4
2.2 Metal, Ceramic, and Carbon Composite Materials 5
2.3 Polymer Matrix Composites 6
2.3.1 Carbon Reinforcing Materials for Polymer Based Composites 8
2.4 Early Carbon Nanomaterials 9
2.4.1 Fullerenes and Carbon Nanotubes 10

2.5 Carbon Nanotube Properties 14

2.5.1 Mechanical Properties of Carbon Nanotubes 15

2.5.2 Carbon Nanotube Reactivity 16
2.6 Carbon Nanotube Polymer-Based Composite Properties 20
2.6.1 Carbon Nanotube Polymer-Based Composite Properties Mechanical
Properties 20
2.6.2 Dispersion of Carbon Nanotubes 21
2.6.3 Alignment of Carbon Nanotubes 24
2.5.4 Novel Approach to Disperse and Align Carbon Nanotube Polymer-
Based Composites In Situ 26
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3 Materials and Materials Characterization 28
3.1 Overview 28
3.2 Materials 28
3.2.1 Carbon Nanotubes 28
3.2.2 Surfactant Sodium Dodecyl Benzene Sulfonate 29
3.2.3 Commerical Block Copolymer Dispersing Agent 29
3.2.4 Pluronic F108 29
3.2.5 Carboyslmethyl Cellulose 30
3.2.5 Sol Gel Precursor Materials 30
3.3 Transmission Electron Microscopy 30
3.4 Raman Spectroscopy 31
3.5 Mechanical Property Characterization 35
3.5.1 Dynamic Mechanical Analysis 35
3.5.2 Compression Testing 37
3.6 X-Ray Diffraction 40
3.6.1 Small Angle X-Ray Scattering 41

3.7 Differential Scanning Calorimetry 42
4 Effects of Different Dispersing Agents on Polymer Carbon Nanotube Composites
45
4.1 Overview 45
4.2 Introduction 45
4.3 Experimental Procedure 47
4.4 Results and Discussion 50
4.4.1 Dispersion Mechanisms 50
4.4.2 Effect of Glass Transition Temperature 56

v i
4.4.3 Effect on Storage, Loss Modulus and Tan Delta 59
4.4.4 Small Angle X-Ray Scattering (SAXS) of SWNT-Epoxy
Composites 66
4.5 Summary of Dispersing Agents Effects on Carbon Nanotube Polymer
Composites 69
5 Alignment of Carbon Nanotubes Under Shear Viscous Flow for Polymer and
Epoxy Composite Systems 70
5.1 Overview 70
5.2 Introduction 70
5.3 Experimental Procedure 72
5.3.1 Polymer Viscous Flow 72
5.3.2 Epoxy Composites 74
5.4 Viscous Polymer Flow Results and Discussion 75
5.4.1 Dispersion of SWNTs 75
5.4.2 Orientation of SWNT in Shear Flow 78
5.5 Epoxy Composite Results and Discussion 85
5.5.1 Dispersion of SWNTs in Shear Flow 85
5.5.2 Orientation of SWNTs in Epoxy Composites 86
5.5.3 Raman Spectroscopy of SWNT in Epoxy Composites 87
5.5.4 Dynamic Mechanical Analysis of SWNT in Epoxy Composites 91
5.5.4.1 Effect on Glass Transition Temperature 91
5.5.4.2 Effect on Storage and Loss Modulus and Tan Delta 93
5.6 Summary of Viscous Polymer and Epoxy Composite Systems 96
6 Properties of Carbon Nanotube-Polymer Composites Aligned in a Magnetic Fiel
97
6.1 Overview 97
6.2 Introduction 97
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6.3 Experimental Procedure 98
6.4. Results and Discussion of Magnetic Field Aligned Carbon Nanotubes101
6.4.1 Effect of Glass Transition Temperature 102
6.4.2 Effect of Storage, Loss Modulus and Tan Detla 105
6.4.3 Effect of Young’s Modulus 111
6.4.4 Effect on Raman Scattering 112
6.5 Summary of Mechanical Properties of Magnetic Field Alignment of
Carbon Nanotubes 115
7 Carbon Nanotubes Decorated with Iron (III) Oxide Particles from Sol Gel
Processing for Magnetic Applications 117
7.1 Overview 117
7.2 Introduction 118
7.3 Experimental Procedure 120

7.4 Results and Discussion of Iron (III) Oxide Decorated Carbon Nanotubes
122
7.4.1 Modified Sol Gel Processing of Iron (III) Oxide Particles 122
7.4.2 Decoration of CNTs with Iron (III) Oxide Nanoparticles 131
7.5 Summary of Decorating Carbon Nanotubes with Iron (III) Oxide
Nanoparticles 133
8 Magnetic Alignment of Iron (III) Oxide Decorated Carbon Nanotubes Polymer
Composites 134
8.1 Overview 134
8.2 Introduction 134
8.3 Experimental Procedure 135
8.4 Results and Discussion of Iron(III) Oxide Decorated Aligned Carbon
Nanotubes 138

8.4.1 Effect on Glass Transition Temperature 139
8.4.2 Compression Testing 141
vi ii
8.4.3 Effect on Young’s Modulus 145
8.4.4 Effect on Raman Scattering 150
8.5 Summary of Decorating Carbon Nanotubes with Iron (III) Oxide
Nanoparticles for Magnetic Field Alignment 154
9 Conclusions 156
10 Recommendations 162
APPENDIX A 164
REFERENCES 178
VITA 201
ix
LIST OF TABLES
Page
Table 2.1: Young’s Modulus Data for SWNT and MWNTs 16

Table 4.1: Summary of the measured and calculated mechanical properties, such as glass
transition temperature, elastic modulus, storage modulus, and loss modulus for
the various samples characterized in this work. 49

Table 5.1: Summary of the mechanical properties of the various SWNT-containing
solutions. 79

Table 6.1: Summary of the measured and calculated mechanical properties, such as glass
transition temperature, elastic modulus, storage modulus, and loss modulus for
the various samples characterized in this work. 101

Table 7.1: Summary of the characteristics of the modified sol-gel process for the various
reactions performed in this study. Specific molar quantities for each reactant
are described in the Experimental section. 121
Table 7.2: Summary of the iron oxide product size and morphology resulting from the
modified sol-gel process for the various reactions performed in this study.
125
Table 8.1: Summary of the sample parameters, such as carbon nanotube content, iron
oxide batches, and magnetic field applied. 137

Table 8.2: Summary of the measured and determined sample properties, such as glass
transition temperature, carbon nanotube content, iron oxide batches, applied
magnetic field, and Raman analysis. 140

Table 8.3: Summary of the compression test values for the samples in alignment direction
(#a) and perpendicular to alignment direction (#b) coupled with Raman
analysis. 147

Table A.1: Nomenclature for distribution functions 167

Table A.2: Limiting conditions for the two-point probability function 172

x