Title Page
Contents
Abstract 21
Chapter 1. General Introduction 25
1. Introduction 25
2. Processing of polymer composites 30
2.1. Thermoplastic resin 30
2.2. Thermosetting resin 33
3. Various carbonaceous fillers for thermally conductive polymer 35
3.1. Carbon fiber 35
3.2. Carbon nanofiber 37
3.3. Graphene 38
4. Effect of the filler morphology on thermal conductivity 39
4.1. Effect of filler shapes 39
4.2. Effect of filler sizes 40
4.3. Effect of filler hybridization 40
5. The measurement method of thermal conductivity 43
5.1. Laser flash analysis (LFA) 43
5.2. Laser-heating Angstrom method (AC method) 45
5.3. Transient plane source method (TPS) 46
6. Applications of thermally conductive polymer composites. 47
6.1. LED devices 47
6.2. Batteries 48
6.3. Automotive electronic control units (ECU) 48
7. Reference 49
Chapter 2. Effective Heat Transfer Pathways of Thermally Conductive Networks Formed by One-Dimensional Carbon Materials with Different Sizes 53
1. Introduction 53
2. Materials and methods 57
2.1. Thermally conductive filler materials 57
2.2. Preparation of flexible carbon-based films 58
2.3. Preparation of thermally conductive epoxy-based composites 61
2.4. In-plane thermal conductivity measurements of flexible carbon-based films and epoxy-based composites 62
3. Results and discussion 65
3.1. Surface morphology and thermal conductivity of FWCNT films 65
3.2. Surface morphology and thermal conductivity of FWCNT-MPCF hybrid films 69
3.3. Effect of thermal annealing on thermal conductivity of FWCNT-MPCF hybrid films 73
3.4. Effect of MPCF length on thermal conductivity of FWCNT-MPCF hybrid films 78
3.5. Effect of incorporation of Ag nanoparticles on thermal conductivity of FWCNT-MPCF hybrid films 81
3.6. Thermal conductivity of epoxy-based composites 87
4. Conclusions 90
5. References 92
Chapter 3. Synergistic Effects of Hybrid Carbonaceous Fillers of Carbon Fibers and Reduced Graphene Oxides on Enhanced Heat-Dissipation Capability of Polymer Composites 98
1. Introduction 98
2. Materials and methods 103
2.1. Preparation of thermally conductive epoxy-based composites 103
2.2. Characterization of thermally conductive carbonaceous fillers and epoxy-based composites 107
3. Results and discussion 110
3.1. Characterization of thermally conductive carbonaceous fillers 110
3.2. Effect of mesophase pitch-based carbon fiber (MPCF) length on thermal conductivity of epoxy-based composites 115
3.3. Synergistic effects of hybrid fillers of MPCF and reduced graphene oxide (rGO) on thermal conductivity of epoxy-based composites 119
3.4. Theoretical approach of thermal conductivity in the MPCF-rGO/epoxy composites 129
4. Conclusions 136
5. References 138
Chapter 4. Thermal Conductivity Enhancement of Epoxy-Based Composites Reinforced with High-Temperature Heat-Treated Reduced Graphene Oxides 144
1. Introduction 144
2. Materials and methods 149
2.1. Materials 149
2.2. Preparation of thermally conductive epoxy-based composites 151
2.3. Characterization 151
3. Results and discussion 153
3.1. Structural characterization of the pristine and high-temperature heat-treated rGOs 153
3.2. Morphologies and electrical conductivities of pristine and high-temperature heat-treated rGOs 166
3.3. Characterization of epoxy-based composites 170
4. Conclusions 177
5. References 179
Chapter 5. General Conclusion 185
Table 1.1. Thermal conductivities of various thermally conductive fillers. 28
Table 1.2. Thermal conductivities of polymer composites. 29
Table 1.3. Thermal conductivities of thermoplastics. 32
Table 1.4. Thermal conductivities of thermosetting. 34
Table 3.1. Summary of basic properties of carbonaceous fillers. 105
Table 4.1. Band (D, G, and 2D) positions and ID/IG and I2D/IG...[이미지참조] 161
Table 4.2. The (002) peak, FWHM, d-spacing (d002), and...[이미지참조] 163
Table 4.3. Elemental composition obtained from XPS analysis of... 165
Figure 1.1. FE-SEM image of mesophase pitch-based carbon fiber. 36
Figure 1.2. Schematic of a single-walled carbon nanotube (SWCNT). 37
Figure 1.3. Schematic of a graphene. 38
Figure 1.4. Schematic of thermal transfer pathway for different... 42
Figure 1.5. Schematic of the different shape fillers network in the... 42
Figure 1.6. Schematic of laser flash analysis system. 44
Figure 1.7. Schematic of laser-heating Angstrom method system. 45
Figure 1.8. Schematic of transient plane source method system. 46
Figure 2.1. Schematic of fabrication process of carbon-based films. 60
Figure 2.2. Schematic of thermal conductivity measurement... 64
Figure 2.3. FE-SEM images of FWCNT films prepared following... 68
Figure 2.4. FE-SEM images of FWCNT-MPCF hybrid films with... 71
Figure 2.5. FE-SEM images of FWCNT-MPCF hybrid films with... 72
Figure 2.6. (a) Raman spectra of pristine and annealed (at 1000... 76
Figure 2.7. (a) FE-SEM images of FWCNT-MPCF hybrid film... 77
Figure 2.8. (a) Thermal conductivity and (b) to (d) FE-SEM... 80
Figure 2.9. TGA curve of Ag nanoparticles under air atmosphere... 83
Figure 2.10. FE-SEM images of FWCNT-MPCF-Ag hybrid films... 84
Figure 2.11. Measurement of Ag nanoparticle sizes using... 85
Figure 2.12. Thermal conductivity of FWCNT-MPCF-Ag hybrid... 86
Figure 2.13. Thermal conductivity of epoxy-based composites... 89
Figure 3.1. Schematic of fabrication process of epoxy-based composites. 106
Figure 3.2. Schematic of surface temperature monitoring system 109
Figure 3.3. FE-SEM images of mesophase pitch-based carbon... 113
Figure 3.4. (a) Raman spectra and (b) electrical conductivity... 114
Figure 3.5. In-plane thermal conductivity values of epoxy-based.. 117
Figure 3.6. (a) Infrared thermal camera images and (b) to (d)... 118
Figure 3.7. FE-SEM images of epoxy-based composites... 124
Figure 3.8. In-plane thermal conductivity values of epoxy-based... 125
Figure 3.9. (a) Infrared thermal camera images and (b) to (d)... 126
Figure 3.10. Electrical conductivity values of epoxy-based... 127
Figure 3.11. In-plane thermal conductivity values of... 128
Figure 3.12. Experimental and theoretical thermal conductivity... 134
Figure 3.13. Experimental and theoretical thermal conductivity... 135
Figure 4.1. High-temperature heat-treatment conditions of rGOs. 150
Figure 4.2. (a) Raman spectra and (b) XRD patterns of p-rGO,... 160
Figure 4.3. Enlarged 2D-band regions of the Raman spectra... 162
Figure 4.4. (a) Wide-scan and deconvoluted C 1s XPS spectra of... 164
Figure 4.5. FE-SEM images of (a) p-rGO, (b) h-rGO-1000, (c)... 168
Figure 4.6. Electrical conductivies of p-rGO, h-rGO-1000,... 169
Figure 4.7. FE-SEM images of (a) pure epoxy rasin and... 174
Figure 4.8. Thermal conductivities of pure epoxy resin and... 175
Figure 4.9. (a) Infrared earner a images (a) and (b) temperature-time... 176