광전도성 고분자 PPT-TPA 에 기초한 광굴절 복합재료에 관한 연구
A Study on the Photorefractive Composites Based on Photoconducting Polymers (PPT-TPA)
- 발행기관 亞洲大學校 大學院
- 지도교수 李碩炫
- 발행년도 2005
- 학위수여년월 2005. 2
- 학위명 석사
- 학과 및 전공 일반대학원 분자과학기술학과
- 본문언어 영어
초록/요약
A new nematic-like mesophase photoconductive polymer PPT-TPA consisting of wholly aromatic rigid backbone of poly(p-phenyleneterephthalate), PPT and pendent hole-transporting triphenylamine (TPA) groups attached to the ends of oxydecyl spacers has been synthesized. The photorefractive composite contains the photoconductor PPT-TPA, the chromophore diethylaminodicyanostyrene (DDCST), and the photosensitizer C60. Although no plasticizer was added, the glass transition temperature T_(g) of the composite is 15 ℃ as for a low-T_(g) photorefractive material. We investigate the correlation between the mesophase structure and its optical/physical properties by X-ray diffraction, photoconductive and photorefractive experiments. The new composite and its properties are compared to similar polymer composites (PPT-CZ) with different mesophase structure, which were studied previously and have shown very good photorefractive properties. Despite of a lower photoconductivity of the new photorefractive composite PPT-TPA(n=10):DDCST:C60 this material shows a higher photorefractive sensitivity S_(n2) of 2 ± 0.2 cm²/kJ at E =50 V/μm than the previously synthesized composite PPT-CZ(n=10):DDCST:C_(60).
more초록/요약
본 연구에서는 견고한 주사슬 poly(p-phenyleneterephthalate), PPT와 곁가지에 광전도성 그룹인 트리페닐아민 triphenylamine (TPA) 기가 알킬 사슬에 연결되어 있는 새로운 광전도성 고분자 PPT-TPA를 합성하였다. 합성되어진 광전도성 고분자 PPT-TPA, 비선형 광학기 diethylaminodicyanostyrene (DDCST) , 그리고sensitizer로 C60를 혼합하여 광굴절 복합재료를 제조하였고 그 특성을 연구하였다. 일반적으로 유리전이온도를 낮추기 위해 사용되어 지는 가소제는 첨가하지 않았음에도 불구하고 광굴절 혼합물은 15 oC 의 낮은 유리전이온도를 나타내었다. 그리고 DSC, X-ray diffraction, 광전도성 과 광굴절 특성 측정을 통해 광학적, 물리적 특성과 복합재료가 형성하는 구조간의 상관 관계에 대하여 조사하였다. 또한 선행 연구되어진 유사한 고분자 PPT-CZ복합재료와의 연구 결과를 비교 분석하였다. PPT-TPA(n=10) : DDCST : C60 혼합물은 PPT-CZ(n=10):DDCST:C60 보다 낮은 광전도성에도 불구하고 더 높은 광굴절 감도(photorefractive sensitivity) S_(n2) of 2 ± 0.2 cm²/kJ (E =50 V/μm)를 나타내었다.
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CONTENTS
List of Figures ⅳ
List of Tables ⅶ
Acknowledgement (in Korean)ⅷ
Abstract ⅸ
Abstract (in Korean) ⅹ
Ⅰ. Introduction 1
Ⅱ. Brief review 4
Ⅱ.1 Fundamentals of photorefractⅣity 4
Ⅱ.2 Space-Charge Field Formation 8
Ⅱ.3 Orientational Enhancement Effect 11
Ⅱ.4 Organic PhotorefractⅣe material systems 14
A. Guest-Host Polymers 14
B. Glassy and Fully Functionalized Materials 16
B.1 Fully Functionalized Polymers 16
B.2 Low Molecular Mass Glasses 17
C. Liquid Crystals 18
Ⅱ.5 Experimental Techniques 20
A. PhotoconductⅣity 20
B. Linear Electro-Optic Effect 21
C. Two-Beam Coupling 22
D. Four-Wave Mixing 24
Ⅲ. Experimental 26
Ⅲ.1 Synthesis 26
A. Materials 26
B. General characterization 26
C. Synthesis of monomers 28
D. Polymerization 30
Ⅲ.2 PhotorefractⅣe Sample Preparation 31
Ⅲ.3 PhotoconductⅣe and electro-optic properties 32
A. DC PhotoconductⅣity 32
B. Electro-optic coefficient 32
Ⅲ.4 PhotorefractⅣe properties 33
A. Two-beam coupling 33
B. Bragg diffraction 33
Ⅳ. Results and Discussion 35
Ⅳ.1 Synthesis and Characterization 35
Ⅳ.2 Linear Optical Properties 44
Ⅳ.3 Thermal Properties 44
Ⅳ.4 Mesophasic Structures 45
Ⅳ.5 Electro-optic and PhotoconductⅣe Properties 52
Ⅳ.6 PhotorefractⅣe Characterizations 53
Ⅴ. Conclusion 62
References 64
