Title Page
Abstract
Contents
Chapter 1. Introduction 29
1.1. Dynamic Covalent Polymer Networks 30
1.2. Polymeric Materials for Soft Robotics Applications 33
1.3. Sulfur-Rich Copolymers for Infrared Imaging 36
1.4. Motivation 38
1.5. References 41
Chapter 2. Dynamic Photo-Controllable Liquid Crystalline Networks for Monolithically Assembled 3D Soft Transformable Robot 53
2.1. Introduction 54
2.2. Results and Discussion 58
2.2.1. Preparation of a photo-controllable LCN with static and dynamic dual-crosslinks 58
2.2.2. Reversible assembly/disassembly and shape reconfiguration of pc-LCN films 60
2.2.3. Monolithically assembled, transformable 3D architectures based on pc-LCN-B films 64
2.2.4. Selective visible light responsiveness of pc-LCNs with different dopant dyes 65
2.2.5. Fabrication and movements of 3D soft transformable robot 67
2.3. Conclusion 72
2.4. Experimental 74
2.5. References 78
Chapter 3. Multifunctional Poly(thiourethane) Vitrimer with Variable Stiffness and Lego-like Assembly/Disassembly Properties for 3D Transformable Soft Robot 117
3.1. Introduction 118
3.2. Results and Discussion 123
3.2.1. Vitrimer Properties of MFTU 123
3.2.2. Variable Stiffness Properties of MFTU 125
3.2.3. Reversible Assembly/Disassembly of MFTU Films via Hydrogen and Zn Coordination Bonds 129
3.2.4. MFTU for Transformable and Recyclable 3D Soft Robot Applications 131
3.3. Conclusion 135
3.4. Experimental 136
3.5. References 142
Chapter 4. A Microphase Separation Strategy for the Conundrum of Infrared Transparency and Thermomechanical Property in Sulfur-Rich Copolymers 193
4.1. Introduction 194
4.2. Results and Discussion 198
4.3. Conclusion 209
4.4. Experimental 210
4.5. References 219
초록 260
Table 2.1. Effect of RM257 and MBTA contents on bending actuation of the pc-LCN film. 84
Table 2.2. Summary of mechanical properties of pristine and assembled pc-LCN films with different dyes (DB14, DR1, DO13). 85
Table 3.1. Gel fraction and crosslinking density of MFTUs by different excess thiol ratio. 149
Table 3.2. Determined average relaxation times from stress relaxation measurements. 150
Table 3.3. Mechanical properties of MFTU-0-P, MFTU-10-P, and MFTU-20-P films (pristine, 1st, and 2nd reprocessed, respectively).[이미지참조] 151
Table 3.4. Mechanical properties of MFTU-0-R, MFTU-10-R, and MFTU-20-R films (pristine, 1st, and 2nd reprocessed, respectively).[이미지참조] 152
Table 4.1. Characteristics of the poly(S-r-TVB)s with 70 to 90 wt % feed ratio. 224
Table 4.2. E' at 30 ℃, Tg, Tan δ max, and crosslinking density of poly(S-r-TVB)s extracted and calculated from temperature sweep curves of DMA temperature sweep.[이미지참조] 225
Table 4.3. Rheological parameters of poly(S-r-TVB)s extracted and calculated from the viscoelastic master curve. 226
Table 4.4. IR transmittances of poly(S₈₀-r-TVB₂₀), poly(S₈₀-r-DVB₂₀), poly(S₈₀-r-DIB₂₀), poly(S₈₀-r-TIB₂₀), and PMMA. 227
Table 4.5. Refractive indices versus wavelength plot of poly(S-r-TVB) films. 228
Table 4.6. IR transmittances of poly(S₈₀-r-TVB₂₀), poly(S₈₀-r-DVB₂₀), poly(S₈₀-r-DIB₂₀), poly(S₈₀-r-TIB₂₀), and PMMA. 229
Figure 1.1. Schematic illustration of dynamic covalent polymer networks (DCPN) with synergistic combination of thermoplastic and thermoset properties via... 47
Figure 1.2. Schematic illustration of dissociative and associative bond exchange pathways for DCPNs. 48
Figure 1.3. Various stimulus-responsive soft robots. 49
Figure 1.4. Schematic illustration of (a) elasticity and plasticity of DCPN with shape memory properties and (b) crosslinking / dissolution / recrosslinking cycle... 50
Figure 1.5. Schematic illustration of chalcogenide inorganic glass and reprocessable sulfur-rich copolymers for IR lens. 51
Figure 1.6. Fabricating 3D structures from 2D films via (a) adhesive, (b) welding, and (c) post-polymerization processes. 52
Figure 2.1. Schematic illustration of the dual-crosslinked pc-LCN and chemical structures of the components used in the pc-LCN-B. 86
Figure 2.2. Schematic illustration and photographs showing fabrication process of pc-LCN-B. 87
Figure 2.3. a) Cross-sectional SEM image and b) POM images of the splay-aligned pc-LCN-B film (scale bars: 10 μm). 88
Figure 2.4. Visible light-driven actuation of the splay-aligned pc-LCN-B film doped with disperse blue 14 (DB14, 1 mol%). 89
Figure 2.5. Mechanism of dynamic allyl sulfide bond exchange. 90
Figure 2.6. Mechanism for photo-controlled reversible assembly and disassembly of the pc-LCN film. 91
Figure 2.7. Schematic illustration and photographs of UV-controlled assembly-disassembly procedure for pc-LCN-B films (scale bars: 5 mm). 92
Figure 2.8. Cross-sectional SEM images of the assembled and disassembled pc-LCN-B film. 93
Figure 2.9. Self-healing properties of pc-LCN-B under UV irradiation. 94
Figure 2.10. Representative stress-strain curves of pristine and assembled pc-LCN-B films. 95
Figure 2.11. Representative stress-strain curves of pristine and assembled pc-LCN films with a) DR1 and b) DO13 dyes. 96
Figure 2.12. Photographs of (i) pristine, (ii) assembled, and (iii) disassembled films during the photo-controlled reversible assembly-disassembly process, and (iv)... 97
Figure 2.13. Schematic illustration and photographs of physically attached pc-LCN-B films without UV irradiation, showing detachment under tensile stress... 98
Figure 2.14. Schematic illustration and photographs of physically attached LCN-B films without any MBTA crosslinkers (i.e., with 100% RM257 crosslinkers) under... 99
Figure 2.15. Schematic illustration and photographs of chemically welded pc-LCN-B films with only MBTA crosslinkers (i.e., with 0% RM257 crosslinkers)... 100
Figure 2.16. Mechanism for the plasticity-based shape reconfiguration of pc-LCN via dynamic allyl sulfide bond exchange under UV irradiation (0.2 W cm¯², 40 s). 101
Figure 2.17. Consecutive shape reconfiguration of the pc-LCN-B film via cumulative photo-induced plasticity (scale bars: 5 mm). 102
Figure 2.18. Photographs for consecutive photo-controlled shape reconfiguration processes of dye-free pc-LCN (scale bars: 5 mm). 103
Figure 2.19. Bending angle variation of the pc-LCN-B film after UV irradiation (0.2 W cm¯²). Bending angles were measured at 40 s under 660 nm light irradiation.... 104
Figure 2.20. Schematic illustration for the transformation process from pc-LCN-B building blocks to caterpillar-, chrysalis-, and butterfly-mimicking structures. 105
Figure 2.21. Photographs of consecutive building block assembly, shape reconfiguration, photo-responsive actuation, and disassembly of the monolithic 3D... 106
Figure 2.22. Chemical structures of three visible-light-absorbing dyes with almost non-interfered absorptions; Disperse Red 1 (DR1, 532 nm), Disperse Blue 14... 107
Figure 2.23. Profiles of temperature vs. time of different dye-doped pc-LCN films under a) 532 nm, b) 405 nm, and c) 660 nm light irradiation. 108
Figure 2.24. UV-Vis absorption spectra of DR1, DB14, and DO13, and the corresponding pc-LCN-R, pc-LCN-B, and pc-LCN-O films (dye content=1 mol%), respectively. 109
Figure 2.25. Photographs of independent bending actuation of the different dye-doped pc-LCN films under 532 nm, 660 nm, and 405 nm light irradiation (scale... 110
Figure 2.26. Profiles of the induced bending angle degrees of different dye-doped pc-LCN films against irradiation time under d) 532 nm, e) 660 nm, and f) 405 nm... 111
Figure 2.27. The actuation behavior of pc-LCN according to different thicknesses. All pc-LCNs with thicknesses of 30, 50, and 80 µm were demonstrated (scale bars: 10mm). 112
Figure 2.28. Demonstration of monolithically assembled 3D soft robots, capable of photo-controlled reversible assembly/disassembly-and shape reconfiguration-... 113
Figure 2.29. Schematic illustrations and corresponding photographs are shown at the top and bottom of the figure, respectively (scale bars: 5 mm). a) Processes of... 114
Figure 2.30. Trace coordinates of the a) soft rolling robot locomotion from position (I) to position (II), b) soft tripod robot locomotion from position (II) to position (III),... 115
Figure 2.31. Schematic illustration and photographs of the detailed manufacturing procedures of a) soft tripod robot and b) soft gripper (scale bars: 5 mm). 116
Figure 3.1. Schematic chemical structures for the synthesis of excess thiol multifunctional poly(thiourethane) (MFTU). 153
Figure 3.2. Schematic illustrations of the MFTU with (a) vitrimer properties via dynamic thiourethane bond exchange under Zn(DTC)₂catalysis, (b) stiffness... 154
Figure 3.3. Bond lengths and bond dissociation energies of (a) urethane bond and (b) thiourethane bond. 155
Figure 3.4. DSC thermograms of poly(thiourethane) by different ratio of PETMP with excess thiol of 10 mol %. 156
Figure 3.5. FT-IR spectra of MFTUs by different excess thiol ratio. 157
Figure 3.6. TGA curve of MFTU-10. 158
Figure 3.7. Proposed pathways of thiourethane dynamic bond exchange chemistry. 159
Figure 3.8. Normalized stress-relaxation of (a) MFTU-10 and DTU-10 under different temperatures of at 120, 140, 160, and 180 ℃. The dashed line indicates... 160
Figure 3.9. Activation energy comparison of MFTU-10 and DTU-10, fitted to Arrhenius equations. 161
Figure 3.10. Compared images for the reprocessability of MFTU-10 and DTU-10 (scale bars: 10 mm). 162
Figure 3.11. Self-healing properties of MFTU-10 (140 ℃ for 12 h). 163
Figure 3.12. Representative stress-strain curves of MFTU-10 after reprocessing (under 10 MPa at 140 ℃ for 30 min). 164
Figure 3.13. Stress-strain curves of reprocessed (a) MFTU-0-P and (b) MFTU-20-P films (pristine, 1st, and 2nd reprocessed).[이미지참조] 165
Figure 3.14. Recycling of MFTU-10 via the bulk process with excess thiol addition. 166
Figure 3.15. DSC thermograms of MFTU-10-R and MFTU-10-P. 167
Figure 3.16. DMA curve of MFTU-10 at a constant frequency of 1 Hz and a heating rate of 5 ℃ min¯¹, and dynamic strain of 1 %. 168
Figure 3.17. Non-isothermal creep test of MFTU-10 by temperature sweep. 169
Figure 3.18. Baseline-subtracted in-situ 1D WAXS profiles of MFTU-10. 170
Figure 3.19. Baseline-subtracted 1D WAXS profile of MFTU-10 at 26.8 ℃. The solid lines represent measured data, and the dashed lines represent deconvoluted... 171
Figure 3.20. Respective stress-strain curves of MFTU-10-R and MFTU-10-P. 172
Figure 3.21. The respective stress-strain curves of (a) MFTU-0-R, (b) MFTU-10-R, and (c) MFTU-20-R with programmed as rigid states after reprocessed (pristine,... 173
Figure 3.22. The stress-strain curves of (a) MFTU and (b) MFTU-20 according to stiffness programming after reprocessed, respectively. 174
Figure 3.23. Demonstration of 1 kg weight support test by stiffness states of four wheel-shape MFTU-10s. 175
Figure 3.24. In-situ measurement of storage modulus (E′) of MFTU-10-P as a function of time. 176
Figure 3.25. Real-time FT-IR spectra of the H-bonds of MFTU-10 cooled down to RT after heating. 177
Figure 3.26. Real-time FT-IR spectra for the hydrogen bond of MFTU-10 cooled down to RT after heating. 178
Figure 3.27. (a) Supposed stereochemical structures for DODT and Zn(DTC)₂mixture. (b) In-situ ¹H NMR spectra of Zn(DTC)₂-based modeling compound at... 179
Figure 3.28. In-situ ¹H NMR spectra of DBTDL-based modeling compound at variable temperatures of 10℃, 25 ℃, and 45 ℃, respectively. 180
Figure 3.29. Respective stress-strain curves of assembled MFTU films by different excess thiol ratios. 181
Figure 3.30. Images before and after heat application for 60 ℃ to an assembled MFTU-10 film capable of withstanding a weight of 200 g. 182
Figure 3.31. Images of the assembly process of MFTU film after physically fractured. 183
Figure 3.32. Compared FT-IR spectra of hydrogen bonds for pristine and physically fractured surface of MFTU-10. 184
Figure 3.33. Fabrication processes of the soft hand robot through building blocks made after welding MFTU-10 and MFTU-10-Fe₃O₄ composite films with... 185
Figure 3.34. Magnetic field actuation test of finger parts of soft hand robot according to (a) rigid and (b) pliable states of the MFTU-10. 186
Figure 3.35. Demonstration of the rock scissors paper game using actuation under the magnetic field according to the stiffness state of the MFTU-10. 187
Figure 3.36. Transforming process to a soft receiver from a soft hand robot by disassembling, permanently shape fixing, and welding. 188
Figure 3.37. Actuation of rigid state soft receiver under magnetic field. 189
Figure 3.38. Demonstrations of the soft receiver with cargo delivery actuation by programming to a pliable state after gripping by programming from a pliable to a... 190
Figure 3.39. Recycling mechanism of the soft receiver via bulk depolymerization and polymerization processes. 191
Figure 3.40. Comparison of stress-strain curves for MFTU-10-P and recycled MFTU-10-P. 192
Figure 4.1. Schematic illustration for the synthesis of poly(S-r-TVB) from the ES and TVB, and its in-situ microphase-separated architecture for IR optical applications. 230
Figure 4.2. Schematic illustration for the synthesis procedure of poly(S-r-TVB)s. 231
Figure 4.3. FT-IR (ATR mode) spectra of TVB monomer, poly(S₈₀-r-TVB₂₀), and PTVB. 232
Figure 4.4. XRD profiles of ES and poly(S-r-TVB)s with (a) 10-30 wt % and (b) 5 wt % TVB contents. 233
Figure 4.5. (a) Homogeneous and complete product of poly(S₇₀-r-TVB₃₀) and (b) heterogeneous and incomplete product of poly(S₆₀-r-TVB₄₀). 234
Figure 4.6. (a) ¹³C CP-MAS NMR spectra of PTVB and poly(S-r-TVB)s. (b) Expected chemical structure of poly(S-r-TVB)s with ¹³C NMR peak assignments. 235
Figure 4.7. Tapping mode AFM phase image of poly(S₈₀-r-TVB₂₀) and corresponding schematic illustration of microphase-separated domains (scale bars: 10nm). 236
Figure 4.8. Tapping mode AFM images of poly(S-r-TVB)s. (a) Phase-contrast images and (b) Z-height contrast images. All the scale bars are 100 nm. 237
Figure 4.9. DSC thermograms of poly(S-r-TVB)s. 238
Figure 4.10. 1D X-ray scattering profiles for poly(S-r-TVB)s 239
Figure 4.11. Kratky plot of poly(S₈₀-r-TVB₂₀). 240
Figure 4.12. (a) Baseline-subtracted 1D WAXS profiles of poly(S-r-TVB)s. The solid lines represent measured data, and the dashed lines represent deconvoluted... 241
Figure 4.13. A plot of the peak area vs. TVB ratio of poly(S-r-TVB)s. 242
Figure 4.14. (a) TGA thermograms and (b) derivative TGA profiles of PTVB and poly(S-r-TVB)s. 243
Figure 4.15. Schematic illustration for the preparation of poly(S-r-TVB) films via hot pressing. 244
Figure 4.16. DMA temperature sweep tests of poly(S-r-TVB)s. 245
Figure 4.17. Master curves of poly(S-r-TVB) films at 130 ℃ of reference temperature. 246
Figure 4.18. The result of strain sweep tests of the (a) poly(S₉₀-r-TVB₁₀), (b) poly(S₈₅-r-TVBS₈₅-r-TVB₁₅), and (c) poly(S₈₀-r-TVB₂₀). The red dashed lines indicate... 247
Figure 4.19. Plots of crosslinking density and plateau modulus (GN⁰) as a function of TVB contents in poly(S-r-TVB)s. 248
Figure 4.20. Plots of complex viscosity versus angular frequency for poly(S-r-TVB)s. The solid lines denote estimated fitting via the Carreau-Yasuda model. 249
Figure 4.21. DSC curves of poly(S₈₀-r-TVB₂₀), poly(S₈₀-r-DVB₂₀), poly(S₈₀-r-DIB₂₀), and poly(S₈₀-r-TIB₂₀). 250
Figure 4.22. (a) IR transmission spectra for poly(S₈₀-r-TVB₂₀) and other sulfur-rich copolymers in the literature. (b) refractive indices of poly(S-r-TVB)s. 251
Figure 4.23. Plots of MWIR/LWIR transmittance vs. Tg for poly(S₈₀-r-TVB₂₀) and other sulfur-rich copolymers in the literature.[이미지참조] 252
Figure 4.24. IR transmittance of PMMA and poly(S-r-TVB) films in the range of (a) MWIR (3-5 µm) and (b) LWIR (7-14 µm). The thickness of all films is 1.1 mm. 253
Figure 4.25. MWIR thermal images of a male subject were captured (c) without a window sample, through (d) PMMA, and (e) poly(S₈₀-r-TVB₂₀) windows. The... 254
Figure 4.26. A photograph of the LWIR thermal imaging setup. 255
Figure 4.27. LWIR thermal images of 80 ℃ hot plate through the 'KRICT'-patterned sheet captured (f) thermal image w/o window sample, with (g) PMMA,... 256
Figure 4.28. LWIR thermal images of human captured at 28 ℃ through (a) without window sample, (b) PMMA window, and (c) poly(S₈₀-r-TVB₂₀) window. The... 257
Figure 4.29. LWIR images captured (a) without a window and through (b) PMMA and (c) poly(S₈₀-r-TVB₂₀) windows. Each window was placed in front of the... 258
Figure 4.30. MWIR thermal images captured (a) without window and through (b) PMMA and (c-e) poly(S-r-TVB) windows. Each window was placed in front of the... 259