Title Page
Abstract
국문요약
Contents
1. INTRODUCTION 11
2. EXPERIMENTAL 16
2.1. Materials 16
2.2. Equipment 17
2.3. Synthesis of monomers 19
2.3.1. Synthesis of 2,7-dibromo-9,9-bis(6-hydroxyhexyl)fluorene (F6OH) 19
2.3.2. Synthesis of 9,9-dioctyl-2,7-dibromofluorene 19
2.3.3. Synthesis of 2,2'-(9,9-dioctyl-9H-fluorene-2,7-diyl)bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolane) (F8-pinB) 20
2.3.4. Synthesis of 4,7-di(2-thienyl)-2,1,3-benzothiadiazole (TBT) 21
2.3.5. Synthesis of 4,7-Bis(2-bromo-5-thienyl)-2,1,3-benzothiadiazole (DBTBT) 22
2.3.6. Synthesis of 3,7-dibromodibenzothiophene 5,5-dioxide (DBSO) 22
2.4. Synthesis of polymers 23
2.4.1. Synthesis of poly(2,7-dibromo-9,9-bis(6-hydroxyhexyl)fluorene-co-9,9-dioctyl-9H-fluorene-co-4,7-di(2-thienyl)-2,1,3-benzothiadiazole) (P(F6OH-F8-TBT)) 23
2.4.2. Synthesis of poly(2,7-dibromo-9,9-bis(6-hydroxyhexyl)fluorene-co-9,9-dioctyl-9H-fluorene-co-3,7-dibenzothiophene-S,S-dioxdie) (P(F6OH-F8-SO)) 24
2.4.3. Synthesis of P(F6OH-F8-TBT)-CTA 26
2.4.4. Synthesis of P(F6OH-F8-SO)-CTA 26
2.4.5. Synthesis of P(F6OH-F8-TBT)-g-PVDF 27
2.4.6. Synthesis of P(F6OH-F8-SO)-g-PVDF 29
2.5. Fabrication of device 30
2.5.1. Fabrication of polymer light-emitting diode (PLED) device 30
2.5.2. Fabrication of ferroelectric device for P(F6OH-F8-TBT)-g-PVDF 30
2.5.3. Fabrication of ferroelectric device for P(F6OH-F8-SO)-g-PVDF 31
3. RESULTS AND DISCUSSION 32
3.1. Synthesis of red and blue graft copolymers for use as single SPL materials 32
3.2. Molecular weights of red and blue graft copolymers 41
3.3. Crystal structure of red and blue graft copolymers 42
3.4. Thermal properties of red and blue graft copolymers 45
3.5. Photoluminescence of red and blue graft copolymers 47
3.6. Piezoelectric properties of red and blue graft copolymers 49
3.7. Electroluminescence performance of red and blue graft copolymers 51
3.8. Ferroelectric properties of red and blue graft copolymers 54
4. CONCLUSION 56
5. REFERENCES 57
Table 1. Molecular weights of all synthetic red polymers 42
Table 2. Molecular weights of all synthetic blue polymers 42
Figure 1. Chain conformation of α, β and γ phases of PVDF 12
Figure 2. ¹H NMR spectrum of F6OH 32
Figure 3. ¹H NMR spectrum of F8-pinB 33
Figure 4. ¹H NMR spectrum of TBT 33
Figure 5. ¹H NMR spectrum of DBTBT 34
Figure 6. ¹H NMR spectrum of DBSO 34
Figure 7. ¹H NMR spectrum of P(F6OH-F8-TBT) 35
Figure 8. ¹H NMR spectrum of P(F6OH-F8-TBT)-CTA 36
Figure 9. ¹H NMR spectra of P(F6OH-F8-TBT)-g-PVDF separated according to PVDF chain length 38
Figure 10. ¹H NMR spectrum of P(F6OH-F8-SO) 39
Figure 11. ¹H NMR spectrum of P(F6OH-F8-SO)-CTA 40
Figure 12. ¹H NMR spectra of P(F6OH-F8-SO)-g-PVDF 41
Figure 13. FT-IR spectra of (a) P(F6OH-F8-TBT) and P(F6OH-F8-TBT)-CTA; (b) FT-IR spectra of P(F6OH-F8-TBT)-g-PVDF separated according... 43
Figure 14. FT-IR spectra of (a) P(F6OH-F8-SO) and P(F6OH-F8-SO)-CTA; (b) FT-IR spectra of P(F6OH-F8-SO)-g-PVDF 43
Figure 15. Powder XRD patterns of (a) P(F6OH-F8-TBT) and P(F6OH-F8-TBT)-CTA; (b) Powder XRD patterns of P(F6OH-F8-TBT)-g-PVDF... 44
Figure 16. Powder XRD patterns of (a) P(F6OH-F8-SO) and P(F6OH-F8-SO)-CTA; (b) FT-IR spectra of P(F6OH-F8-SO)-g-PVDF 45
Figure 17. TGA curves of (a) red and (b) blue light emitting polymers and PVDF graft copolymers 46
Figure 18. DSC curves of (a) 2nd heating and (b) 2nd cooling cycles of red polymers; DSC curves of (a) 2nd heating and (b) 2nd cooling cycles of blue polymers 47
Figure 19. (a) UV-vis absorption and (b) fluorescence spectra of red polymers in THF solutions 48
Figure 20. (a) UV-vis absorption and (b) fluorescence spectra of blue polymers in THF solutions 49
Figure 21. XRD patterns of (a) P(F6OH-F8-TBT)-g-PVDF and (b) P(F6OH-F8-SO)-g-PVDF films 50
Figure 22. The butterfly loops of (a) P(F6OH-F8-TBT)-g-PVDF (S), (b) P(F6OH-F8-TBT)-g-PVDF (L), (c) P(F6OH-F8-SO)-g-PVDF (S), and (d)... 51
Figure 23. Electroluminescence properties of devices with structure of ITO/PEDOT:PSS/Polymer/LiF/Al of (a) P(F6OH-F8-TBT) and (b) P(F6OH-F8-TBT)-CTA 52
Figure 24. Electroluminescence properties of devices with structure of ITO/PEDOT:PSS/Polymer/LiF/Al of (a) P(F6OH-F8-SO), (b) P(F6OH-F8-... 53
Figure 25. AFM images of (a) P(F6OH-F8-TBT)-g-PVDF (S), (b) P(F6OH-F8-TBT)-g-PVDF (L), (c) P(F6OH-F8-SO)-g-PVDF (S) and (d) P(F6OH-F8-SO)-g-PVDF (L) 54
Figure 26. Polarization-electric field (P-E) hysteresis loops of (a) P(F6OH-F8-TBT)-g-PVDF and (b) P(F6OH-F8-SO)-g-PVDF 55
Scheme 1. Synthetic scheme of red light-emitting polymer through (a) Suzuki coupling and (b) Stille coupling 15
Scheme 2. Synthesis of 2,7-dibromo-9,9-bis(6-hydroxyhexyl)fluorene (F6OH) 19
Scheme 3. Synthesis of 9,9-dioctyl-2,7-dibromofluorene 20
Scheme 4. Synthesis of 2,2'-(9,9-dioctyl-9H-fluorene-2,7-diyl)bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolane) (F8-pinB) 20
Scheme 5. Synthesis of 4,7-di(2-thienyl)-2,1,3-benzothiadiazole (TBT) 21
Scheme 6. Synthesis of 4,7-bis(2-bromo-5-thienyl)-2,1,3-benzothiadiazole (DBTBT) 22
Scheme 7. Synthesis of 3,7-dibromodibenzothiophene 5,5-dioxide (DBSO) 23
Scheme 8. Synthesis of red light-emitting polymer, P(F6OH-F8-TBT) via 23
Scheme 9. Synthesis of blue light-emitting polymer, P(F6OH-F8-SO) via Suzuki polycondensation 25
Scheme 10. Synthesis of P(F6OH-F8-TBT)-CTA via EDC coupling reaction 26
Scheme 11. Synthesis of P(F6OH-F8-SO)-CTA via EDC coupling reaction 27
Scheme 12. Synthesis of P(F6OH-F8-TBT)-g-PVDF via RAFT polymerization 28
Scheme 13. Synthesis of P(F6OH-F8-SO)-g-PVDF via RAFT polymerization 29