Title Page
ABSTRACT
Contents
1. Electromagnetic Interference (EMI) and Shielding 21
1.1. Introduction 21
1.2. EMI Shielding Mechanisms 23
1.3. Experimental and theoretical calculation of EMI Shielding Effectiveness (SE) 25
1.4. Materials for EMI Shielding 27
1.5. Effective Structural Designs of EMI Shielding Materials 31
1.6. Two-Dimensional MXenes for EMI Shielding 34
2. Ti3C2Tx MXene and Polystyrene Composite Films[이미지참조] 42
2.1. Introduction 42
2.2. Experimental 44
2.2.1. Materials 44
2.2.2. Synthesis of Ti3C2Tx MXene[이미지참조] 45
2.2.3. Synthesis of Polystyrene beads 45
2.2.4. Fabrication of Ti3C2Tx/PS nanocomposite films[이미지참조] 46
2.2.5. Materials Characterization 48
2.3. Results and Discussion 48
2.3.1. SEM and TEM measurements of Ti3C2Tx and Ti3C2Tx/PS nanocomposite films[이미지참조] 48
2.3.2. XRD, XPS, and electrical conductivity of Ti3C2Tx and Ti3C2Tx/PS nanocomposite films[이미지참조] 52
2.3.3. EMI SE measurements 56
2.3.4. EMI SE vs. surface area of Ti3C2Tx/PS nanocomposite films[이미지참조] 60
2.4. Conclusion 63
3. Ti3C2Tx MXene and Carbon Nanotubes Aerogels[이미지참조] 65
3.1. Introduction 65
3.2. Experimental 68
3.2.1. Materials 68
3.2.2. Synthesis of Ti3C2Tx MXene[이미지참조] 69
3.2.3. Bidirectional freezing of Ti3C2Tx/CNTs hybrid aerogel[이미지참조] 69
3.2.4. Materials Characterization 71
3.3. Results and Discussion 72
3.3.1. SEM and TEM analysis of Ti3C2Tx MXene, CNTs, and Ti3C2Tx/CNTs aerogel[이미지참조] 72
3.3.2. XRD and XPS analysis of Ti3C2Tx MXene, and Ti3C2Tx/CNTs hybrid aerogel[이미지참조] 77
3.3.3. Compression testing and electrical conductivity of Ti3C2Tx MXene, and Ti3C2Tx/CNTs hybrid aerogel[이미지참조] 81
3.3.4. Electrical conductivity measurements 84
3.3.5. EMI SE measurements 85
3.4. Conclusion 91
4. Thermally Annealed Ti3CNTx MXene Films[이미지참조] 93
4.1. Introduction 93
4.2. Experimental 95
4.2.1. Materials 95
4.2.2. Synthesis of Ti3CNTx MXene[이미지참조] 96
4.2.3. Synthesis of Ti3C2Tx MXene[이미지참조] 97
4.2.4. Materials Characterization 97
4.2.5. Experimental and theoretical EMI SE calculations 99
4.3. Results and Discussion 99
4.3.1. XRD analysis of Ti₃AlCN, and Ti₃AlC₂ MAX and corresponding MXenes 99
4.3.2. Thermal annealing of Ti3CNTx, and Ti3C2Tx MXenes[이미지참조] 100
4.3.3. TGA-MS spectroscopy of Ti3CNTx, and Ti3C2Tx MXenes[이미지참조] 102
4.3.4. Microstructural analysis and porosity calculations in annealed MXenes' films 103
4.3.5. Electrical conductivity measurements 108
4.3.6. EMI SE measurements 110
4.3.7. Comparison of experimental and theoretical EMI SE calculations 116
4.3.8. Comparison of EMI SE of Ti3CNTx MXene with other materials[이미지참조] 120
4.4. Conclusion 125
5. References 127
Table 3.1. Density, porosity, electrical conductivity, and compression... 81
Table 3.2. Comparative EMI shielding performance of various shielding materials. 89
Table 4.1. EMI SE of various shielding materials. 123
Figure 1.1. Schematic representations of propagation of EMWs with... 24
Figure 1.2. The interaction between incident electromagnetic waves and... 34
Figure 1.3. (a) Elements in MAX phase materials and corresponding... 40
Figure 2.1. Schematic illustration showing overall procedure for fabrication... 47
Figure 2.2. Structure and morphology of Ti3C2Tx MXene, PS beads,...[이미지참조] 49
Figure 2.3. Structural morphology of Ti3C2Tx/PS nanocomposite films.[이미지참조] 51
Figure 2.4. Structural morphology of Ti3C2Tx/PS composites films.[이미지참조] 52
Figure 2.5. (a) XRD patterns of Ti₃AlC₂ MAX, Ti3C2Tx MXene, and...[이미지참조] 55
Figure 2.6. EMI SE measurements of Ti3C2Tx/PS=9:1 nanocomposites. (a)...[이미지참조] 57
Figure 2.7. EMI SE measurements of Ti3C2Tx/PS=7:3 nanocomposites. (a) SET...[이미지참조] 59
Figure 2.8. EMI SE versus interface area of Ti₃C₂/PS nanocomposites.... 61
Figure 3.1. Schematic of bidirectional freezing method for fabrication of... 68
Figure 3.2. SEM images of (a) Ti₃AlC₂ (MAX phase) and (b) Ti3C2Tx single...[이미지참조] 74
Figure 3.3. SEM images of (a-e) MXene aerogel, (f-h) MXCNT11, (i-k)... 77
Figure 3.4. (a) XRD patterns of Ti3C2Tx MXene, CNTs, and...[이미지참조] 80
Figure 3.5. (a) Stress-strain curves of aerogels (MXene, MXCNT11,... 84
Figure 3.6. (a) EMI SET, (b) SEA and SER of MXene, MXCNT11,...[이미지참조] 87
Figure 3.7. Comparison of EMI shielding performance of MXCNT... 88
Figure 3.8. Schematic representation of possible mechanism of EMI... 91
Figure 4.1. Schematic representation of Ti3CNTx and Ti3C2Tx MXenes. Tx...[이미지참조] 95
Figure 4.2. XRD patterns of Ti₃AlCN and Ti₃AlC₂ MAX and their... 100
Figure 4.3. (A, B) XRD patterns of Ti3CNTx and Ti3C2Tx MXene films...[이미지참조] 102
Figure 4.4. (A) TGA-MS thermogram of Ti3CNTx and Ti3C2Tx MXene, respectively.[이미지참조] 103
Figure 4.5. (A-D) Cross-sectional TEM images of Ti3CNTx films at...[이미지참조] 105
Figure 4.6. Mechanical properties of Ti3CNTx films. (A and B)...[이미지참조] 106
Figure 4.7. XPS survey spectra of (A) Ti3CNTx, and (B) Ti3C2Tx. The...[이미지참조] 108
Figure 4.8. (A) Comparison of electrical conductivity of Ti3CNTx and...[이미지참조] 110
Figure 4.9. EMI shielding measurements of annealed Ti3CNTx and Ti3C2Tx...[이미지참조] 113
Figure 4.10. (A) Absolute EMI SET, SER, and SEA values, and electrical...[이미지참조] 115
Figure 4.11. Validation of transfer matrix method with the experimental... 118
Figure 4.12. Comparison of experimental (represented by square symbols)... 119
Figure 4.13. Comparison of experimental (represented by square symbols)... 120
Figure 4.14. Comparison of EMI SET of reported shielding materials. EMI...[이미지참조] 122