Contents
Streszczenie iii
Abstract xiii
List of Figures iii
1 Introduction 1
1.1 Structural Health Monitoring . . . 2
1.2 Measurement system for Structural Health Monitoring . . . 4
1.3 Strain sensing . . . 5
1.4 Smart materials for Structural Health Monitoring . . . 7
1.5 Summary . . . 8
2 Aim and Scope 9 2.1 Aim . . . 9
2.2 Statement of novelty . . . 9
2.3 Scope of the thesis . . . 10
3 Properties of carbon-based nanostructures 13 3.1 Allotropes of carbon . . . 13
3.2 Carbon Nanotubes . . . 15
3.2.1 Single Walled Carbon Nanotubes (SWNTs) . . . 19
3.2.2 Multiwalled Carbon Nanotubes (MWNTs) . . . 20
3.2.3 Processing of Carbon Nanotubes . . . 21
3.2.4 Properties of Carbon Nanotubes . . . 23
3.3 Properties of CNT based polymer composites . . . 26
3.3.1 Mechanical Properties of CNTs Polymer Nanocomposites . . . 27
CONTENTS
3.3.2 Electrical properties of CNTs Polymer Nanocomposites . . . 28
3.4 Experimental preparation of CNT based composites . . . 30
3.4.1 Solvent casting . . . 31
3.4.2 Melt Mixing . . . 32
3.4.3 In-situ polymerization . . . 32
3.4.4 Dispersion of CNTs . . . 32
3.4.5 Adhesion between CNTs and Polymer . . . 33
3.5 Summary . . . 33
4 Concept of the sensor based on CNT/polymer composites 35 4.1 Sensors based on CNT/polymer composites . . . 35
4.2 Fabrication of CNT based sensors . . . 36
4.3 Concept of the sensor based on CNT's . . . 38
4.3.1 Key assumptions of the sensor . . . 38
4.3.2 Fabrication procedure . . . 39
4.4 Summary . . . 40
5 Experimental preparation of CNT/polymer composites with strain sens-ing properties 42 5.1 Fabrication techniques of the coatings with Carbon Nanotubes . . . 43
5.1.1 Spray coating technique . . . 43
5.1.2 Screen printing technique . . . 43
5.2 Issues considering experimental preparation of CNT polymer composites . 46 5.3 Analysis of internal sensor's structure . . . 47
5.3.1 Investigation of Carbon Nanotubes structure using Transmision Electron Microscope . . . 48
5.3.2 Investigation of sensor internal structure using Scanning Electron Microscope . . . 52
5.4 Strain sensing capabilities of CNT/polymer coating . . . 55
5.4.1 Fatigue testing of CNT/polymer composites . . . 58
5.5 Summary . . . 60
CONTENTS
6 Multiscale framework for CNT polymer composites 62
6.1 General concept of multi-scale model for CNT based composites . . . 63
6.2 Nano scale . . . 65
6.3 Meso scale . . . 69
6.3.1 Mechanical part of the meso-scale model . . . 70
6.3.2 Electrical part of Meso scale . . . 72
6.4 Macro-scale model . . . 76
6.5 Implementation of the Multiscale Model . . . 77
6.6 Results from the multi-scale model . . . 81
6.6.1 Electrical domain . . . 81
6.7 Mechanical domain . . . 85
6.8 Summary . . . 89
7 Experimental validation of the multi-scale model 91 7.1 Validation of mechanical parameters . . . 91
7.1.1 Mechanical parameters validation of the Epoxy resin materials . . 92
7.1.2 Mechanical parameters validation of CNT/epoxy . . . 94
7.2 Electro-mechanical validation . . . 95
7.3 Summary . . . 98
8 Application examples of CNT/based coatings 99 8.1 Strain sensors . . . 99
8.1.1 Strain sensing with RFID platform . . . 100
8.2 Multi-parameter sensing . . . 102
8.2.1 Nanocomposite Generator (NCG) . . . 102
8.2.2 Detection of Methane . . . 105
8.3 Summary . . . 107
9 Summary and Conclusions 108 9.1 Summary of the presented work . . . 108
9.2 Main conclusions and achievements . . . 111
9.3 Future work proposal . . . 112
References 113
CONTENTS
A List of publications related to presented research work 130
