臺灣博碩士論文加值系統

本文針對聚2-甲氧基-5- [ 2’-乙基-己氧基 ] 對苯乙烯在鄰-苯二甲酸二辛酯稀薄溶液中高分子聚集現象與高剪切黏度性質進行實驗探討。鄰-苯二甲酸二辛酯是一種具有高黏度和高沸點特性的溶劑，因此有助於流變實驗的測量。流變實驗的量測配合分子理論分析實驗結果，將可以了解溶液中高分子聚集體結構的特性。實驗結果發現在低剪切速率下，高分子黏度的貢獻隨靜置時間增加而降低，且在熱處理實驗表現出熱不可逆的現象，與先前聚2-甲氧基-5- [2’-乙基-己氧基] 對苯乙烯在低黏度溶劑實驗中所表現的現象一致。在高剪切流場下，高剪切黏度呈現不尋常的兩階段性剪稀現象，我們推論第一階段的剪稀行為是因為高分鏈聚集形成聚集體，在低剪切速率下受到體積排除效應的影響，表現出非牛頓流體現象。第二階段剪稀行為發生在高剪切速率區域，此時流場梯度足影響聚集體中局部結構或分子鏈的行為，造成黏度呈現出較為明顯的剪稀行為。

The viscometric properties of dilute poly[2-methoxy-5-(2’-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV)/dioctyl phthalate (DOP) solutions were systematically investigated in view of the interrelation with the associated aggregation properties. The utility of a high-viscosity solvent—DOP—makes it possible to probe the non-Newtonian solution properties within the accessible range of shear rates in a Couette rheometry. Firstly, low-shear viscosity measurements revealed similar aggregation properties of MEH-PPV in DOP as observed earlier in two low-viscosity solvents, chloroform and toluene. Specifically, similar low-shear viscometric features in response to the effect of constant-temperature aging or short-term thermal annealing have been observed in the aforementioned MEH-PPV solutions. On the other hand, a two-stage viscosity thinning in the polymer contribution to the solution viscosity with increasing shear rate was, for the first time, revealed for a conjugated polymer solution. In addition, the onset of a viscosity thinning occurs at surprisingly low shear rates compared with the estimated relaxation time for individual MEH-PPV chains. The experimental phenomena were subsequently analyzed in view of the effect of aggregate formation using polymer kinetic theories, which led us to the following essential implications: The first viscosity thinning might be due to the effect of excluded volume associated with the suspended polymer aggregates, in analogy to colloidal suspension systems. The second is likely to arise from a flow-induced variation in the average chain environment within individual aggregates. Overall, the experiments revealed, once again, a close correspondence between the viscometric and aggregation properties for conjugated polymer solutions, in which relatively unstable aggregation properties had been linked to weak interchain attractions.

誌謝 i
摘要 ii
Abstract iii
目 錄 iv
表目錄 v
圖目錄 v
第一章 序論 1
1.1 簡介 1
1.2 理論模型 3
1.3 研究動機 4
第二章 實驗 5
2.1 實驗藥品 5
2.2 實驗儀器 6
2.3 樣品配置 7
2.4 實驗注意事項 7
2.5 實驗設計與步驟 8
2.5.1 低剪切黏度實驗 8
2.5.2 高剪切黏度實驗 9
2.6 數據處理 10
2.6.1 黏度的測量 10
2.6.2 標準差的計算 10
2.6.3 剪切速率範圍的選擇 11
第三章 結果與討論 13
3.1 溶液配製與觀察 13
3.1.1 溶劑選擇 13
3.1.2 溶液配製與觀察 15
3.2 高分子聚集體與低剪切黏度的關係 16
3.2.1 恆溫靜置實驗 16
3.2.2 熱處理實驗 18
3.3 高剪切黏度實驗 20
3.3.1 第一階段剪稀區域 22
3.3.2 第二階段剪稀區域 27
第四章 結論 32
參考文獻 33
附錄 36

參考文獻

Akcelrud L., “Electroluminescent polymers,” Prog. Poltm. Sci. 28, 875-962 (2003).

Andrews, N. C.; McHugh, A. J.; Schieber, L. D., “Conformational and rheological dynamics of semiflexible macromolecules undergoing shear flow: A nonequilibrium Brownian dynamics study,” J. Rheol. 42, 281-305 (1998).

Baigent, D. R.; Greenham, N. C.; Gruener, J.; Marks, R. N.; Friend, R. H.; Moratti, S. C.; Holmes, A. B., “Light-emitting diodes fabricated with conjugated polymers: recent progress,” Synth. Met. 67, 3-10 (1994).

Bird, R. B.; Armstrong, R. C.; Hassager, O., Dynamics of Polymeric Liquids: Volume 2 Kinetic Theory (Wiley, 1987).

Burroughes, J. H.; Bradley, D. D. C.; Brown, A. R.; Marks, R. N.; MacKay, K.; Friend, R. H.; Burn, P. L.; Holmes, A. B., “Light-emitting diodes based on conjugated polymers,” Nature 347, 539-541 (1990).

Chen, S. H.; Su, A. C.; Huang, Y. F.; Su, C. H.; Peng, G. Y.; Chen, S. A., “Supramolecular aggregation in bulk Poly(2-methoxy-5-(2’-ethylhexyloxy)-1,4- phenylenevinylene),” Macromolecules 35, 4229-4232 (2002).

Chen, S. H.; Su, A. C.; Chou, H. L.; Peng, G. Y.; Chen, S. A., “Phase behavior and molecular aggregation in bulk poly(2-methoxy-5-(2’-ethylhexyloxy)-1,4- phenylenevinylene), ” Macromolecules 37, 167-173 (2004a).

Chen, S. H.; Su, A. C.; Chang, C. S.; Chen, H. L.; Ho, Derek L.; Tsao, C. S.; Peng, K. Y.; Chen, S. A., “Aging of poly(2-methoxy-5-(2’-ethylhexyloxy)-1,4- phenylenevinylene)/toluene solutions and subsequent effects on luminescence behavior of cast films,” Langmuir 20, 8909-8915 (2004b).

Collision, C. J.; Rothberg, L. J.; Treemaneekarn, V.; Li, Y., “Conformational effects on the photophysics of conjugated polymers: A two species model for MEH-PPV spectroscopy and dynamics,” Macromolecules 34, 2346-2352 (2001).

Dadmun, M. D.; Han, C. C., “A Neutron Scattering Study of the Orientation of Liquid Crystalline Polymer by Shear Flow,” Macromolecules 27, 7522-7532 (1994).

Doi, M.; Edwards, S. F., The theory of Polymer Dynamics (Clarendon, Oxford, 1986).

Friend, R. H.; Gymer, R. W.; Holmes, A. B.; Burroughes, J. H.; Marks, R. N.; Taliani, C.; Bradley, D. D. C.; Dos Santos, D. A.; Bredas, J. L.; Logdlund, M.; Salaneck, W. R., “Electroluminescence in conjugated polymers,” Nature 397, 121-128 (1999).

Gopalakrishnan, V.; Zukoski, C. F., “Effect of attractions on shear thickening in dense suspensions,” J. Rheol. 48, 1321-1344 (2004).
Hide, F.; Diaz-Garcia, M. A.; Schwartz, B. J.; Heeger, A. J., “Semiconducting polymers: a new class of solid-state laser materials,” Science 273, 1833-1836 (1996).

Hsu, J. H.; Fann, W.; Tsao, P. H.; Chuang, K. R.; Chen, S. A., “Fluorescence from Conjugated Polymer Aggregates in Dilute Poor Solution,” J. Phys. Chem. A 103, 2375-2380 (1999).

Hua, C. C.; Chen, C. L.; Chang, C. W.; Lee, C. K.; Chen, S. A., “Viscometric investigation of aggregate formation in dilute conjugated polymer solutions,” J. Rheol. 49, 641-656 (2005).

Jakubiak, R.; Collison, C. J.; Wan, W. C.; Rothberg, L. J.; Hsieh, B. R., “Aggregation Quenching of Luminescence in Electroluminescent Conjugated Polymers,” J. Phys. Chem. A 103, 2394-2398 (1999).

Kratky, O. ; Porod, G., “ R NTGENUNTERSUCHUNG GEL STER FADENMOLEK LE,” Rec. Trav. Chim. 68, 1106- (1949).

Kraft, A.; Grimsda, A.; Holmes, A. B., “Electroluminescent conjugated polymers- seeing polymers in a new light,” Angew. Chem. Int. Ed. 37, 402-428 (1998).

Liu, J.; Shi, Y.; Ma, L.; Yang, Y., “Device performance and polymer morphology in polymer light emitting diodes: The control of device electrical properties and metal/ polymer contact,” J. Appl. Phys. 88, 605-609 (2000).

Liu, J.; Guo, T.; Shi, Y.; Yang, Y., “ Solvation induced morphological effects on the polymer/metal contacts,” J. Appl. Phys. 89, 3668-3673 (2001).

Macosko, C. W., Rheology: Principles, Measruements, and Applications (Wiley-VCH, New York, 1994).

Muller, S. J.; Shaqfeh, E. S. G.; Larson, R. G., “Experimental studies of the onset of oscillatory instability in viscoelastic Taylor-Couette flow,” J. Non-Newtonian Fluid Mech. 46, 315-330 (1993).

Nguyen, T. Q.; Doan, V.; Schwartz, B. J., “Conjugated polymer aggregates in solution: Control of interchain interactions,” J. Chem. Phys. 110, 4068-4078 (1999).

Nguyen, T. Q.; Martini, I. B.; Liu, J.; Schwartz, B. J., “Controlling interchain interactions in conjugated polymers: The effects of chain morphology on exciton- exciton annihilation and aggregation in MEH-PPV films,” J. Phys. Chem. B 104, 237-255 (2000a).

Nguyen, T. Q.; Kwong, R. C.; Thompson, M. E.; Schwartz, B. J., “Improving the performance of conjugated polymer-based devices by control of interchain interactions and polymer film morphology,” Appl. Phys. Lett. 76, 2454-2456 (2000b).

Nguyen, T. Q.; Schwartz, B. J., “Ionomeric control of interchain interactions, morphology, and the electronic properties of conjugated polymer solutions and films,” J. Chem. Phys. 116, 8198-8208 (2002).
Onogi, S.; Asada, T., In Rheology: Vol. 3 (Plenum, New York, 1980).

Pope M.; Kallmann HP.; Magnante P., “Electroluminescence in organic crystals, ” J. Chem. Phys. 38, 2042-2043 (1963).

Peng, G. Y.; Chen, S. A.; Funn, W. S., “Efficient Light Harvesting by Sequential Energy Transfer across Aggregates in Polymers of Finite Conjugational Segments with ShortAliphatic Linkages,” J. Am. Chem. Soc. 123, 11388-11397 (2001).

Rouse, P. E., “A Theory of the Linear Viscoelastic Properties of Dilute Solutions of Coiling Polymers,” J. Chem. Phys. 21, 1272-1280 (1953).

Schwartz, B. J., “Conjugated Polymers Asmolecular Materlals: How Chain Conformation and Film Morphology Influence Energy Transfer and Interchain Interactions,” Annu. Rev. Phys. Chem. 54, 141-172 (2003).

Shi, Y.; Liu, J.; Yang, Y., “Control of polymer thin film morphology and the LED performance,” Polymer Preprints 41, 802-803 (2000a).

Shi, Y.; Liu, J.; Yang, Y., “Device performance and polymer morphology in polymer light emitting diodes: The control of thin film morphology and device quantum efficiency,” J. Appl. Phys. 87, 4254-4263 (2000b).

Smith, W. E.; Zukoski, C. F., “Flow properties of hard structured particle suspensions,” J. Rheol. 48, 1375-1388 (2005).

Tanford, C., Physical Chemistry of Macromolecules (Wiley, New York, 1961).

Tang, C. W.; VanSlyke, S. A., “Organic electroluminescent diodes,” Appl. Phys. Lett. 51, 913-915 (1987).

Zimm, B. H., “Dynamics of Polymer Molecules in Dilute Solution: Viscoelasticity, Flow Birefringence and Dielectric Loss,” J. Chem. Phys. 24, 269-278 (1956).