本研究主要是利用小角度中子散射研究發藍光的導電高分子poly(9,9-dioctylfluorene)(PFO)在甲苯溶液中的聚集行為。研究結果發現，於SANS散射圖譜高解析度區域中，rod-like特性為高分子鏈中的某一區段，而非高分子因缺陷折疊而成的defect cylinder。且隨著高分子濃度的增加，其middle-q(0.006 Å –1≦q≦0.1 Å –1)區域的散射強度對遞減，主要是由於網目高分子鏈形成一網目結構所致，散射區域q≦0.006 Å–1，可以發現散射強度有明顯的增強，主要是由於高分子間有聚集體產生所造成的貢獻。此外SANS圖譜可由two correlation model + rod form factor來適當的描述其曲線。由correlation length與濃度的關係式(ξd~ c-0.5)得知大部分高分子是均勻的分散於甲苯溶劑之中。PFO溶液置於低溫環境下會有凝膠化現象產生，且由POM與DSC此凝膠化現象為一結晶程序且屬於一熱可逆程序。且由升降溫小角度中子散射圖譜可以得知，當溫度重高溫降回室溫時，溶液中可快速的形成新的聚集體，表示此聚集體的形成為一自發的形式。

We use small angle neutron scattering (SANS) to study the aggregation of an electroluminescent polymer, poly(9,9-dioctylfluorene)(PFO), in toluene solution. The scattering profile display the asymptotic behavior of q-1, associated with the rod-like character of the PFO chain on local scale (q-1 > lps = persistence length). The low-q intensity shows strong upturn, signifying prevalent inter-chain aggregation of the polymer. The middle-q intensity decreases with increasing the polymer concentration caused by the chain mashng. And PF chains were mostly uniformly dissolved in toluene. The chains were virtually rod-like, such that the corresponding mesh size in the semidilute regime exhibited c-1/2 dependence. A small fraction of the rod segments aggregated to form nanoscale microdomain, which was responsible for the intensity upturn at low-q. The aggregation was spontaneous, as demonstrated from the thermal reversibility experiment.

參考文獻
[1] Atkins, P. W.; The Elements of Physical Chemistry, Oxford University Press, 1996.
[2] C. Kittel,; Introduction to Solid State Physics, 6th edition, John Wiley & Son, Singapore, 1989
[3] Chien, J.C.W.; Polyacetylene : Chemistry, Physics, and Material Science, Academic Press, Orlando, 1984.
[4] Krivoshei, I. V., Skorobogatov, V. M.; Polyacetylene and Polyarylenes: Synthesis and Conductive properties, Gordon and Breach Science Publishers, 1991.
[5] The Royal Swedish Academy of Sciences, The Nobel Prize in Chemistry, 2000: Conductive polymer, 2000
[6] D. A. Ckoog, D. M. West, F. J. Holler, Fundamentals of Analytical Chemistry, 5th edition, Saunders College Publishing, 1988
[7] Joseph R. Lakowicz, Principles of Fluorescence Spectroscopy, Kluwer Academic / Plenum Publishers, New York, 1999.
[8] Hadziioannou. G, Paul F. van Hutten (Eds.), Semiconducting polymers: Chemistry, Physics and Engineering, WILEY-VCH, 2000.
[9] R. H. Friend, R. W. Gymer, A. B. Holmes, J. H. Burroughes, R. N. Marks, C. Taliani, D. D. C. Bradley, D. A. Dos Santos, J. L. Brédas, M. Lögdlund, W. R. Salaneck. Nature, 397, 121, 1999.
[10] A.R. Inigo, C. H. Tan, W.S. Fann, Y.S. Huang, G.Y. Perng and S.A. Chen., Adv. Mater., 13, 504, 2001.
[11] C. H. Tan, A.R. Inigo, W.S. Fann, P.K. Wei, Y.S. Huang, G.Y. Perng and S.A. Chen, Organic Electronics, 3, 81, 2002.
[12] Jean Roncali, Chem. Rev., 97, 173, 1997.
[13] J. A. Osaheni, S. A. Jenekhe, Macromolecules, 27, 739, 1994.
[14] Inmaculada Prieto, Julie Teetsov, Marye Annw Fox, David A. Vanden Bout, Allen J. Bard, J. Phys. Chem. A, 105, 520, 2001.
[15] K.-Y. Peng, S.-A. Chen, W.-S. Fann, J. Am. Chem. Soc., 123, 11388, 2001.
[16] N. J. Truuo, Modern Molecular Photochemistry, Sausalito, California, University Science Books, 1991.
[17] A. Bernanose, M. Comte, P. Vouaux, J. Chim. Phys., 50, 64, 1953.
[18] A. Bernanose, J. Chim. Phys., 52, 396, 1955.
[19] E. Gurnee, R. Fernandez, US Patent 3 172 862, 1965.
[20] M. Pope, H. Kallman, P. Magnante, J. Chem. Phys., 38, 2024, 1963.
[21] C. Tang, S. VanSlyke, Appl. Phys. Lett., 51, 913, 1987.
[22] J. Burroughes, D. Bradlt, A. Brown, R. Marks., K. Mackay, R. Friand, P. Burn, A. Holmes, Nature, 347, 539, 1990.
[23] R. Wessling, J. Polym. Sci. Polym. Symp., 72, 55, 1985.
[24] D. Braun, A. Heeger, Appl. Phys. Lett., 58, 1982, 1991.
[25] M.Fukuda, K. Sawada, K. Yoshino, Jpn. J. Appl. Phys., 28, L1433, 1989.
[26] Y. Ohmori, K. Yoshino, M. Uchida, Jpn. J. Appl. Phys., 30, L1941, 1991.
[27] Q. Pei, Y. Yang, T. Am. Chem. Soc., 118, 7416, 1996.
[28] D. Neher, Macromol. Rapid Commun., 22, 17, 2001.
[29] M.Fukuda, K. Sawada, K. Yoshino, J. Polym. Sci. Part A: Polym. Chem., 31, 2465, 1993.
[30] U. Scherf, E. J. W. List, Adv. Mater., 14, 477, 2002.
[31] M. Grell, D. D. C. Bradley, X. Long, T. Chamberlain, M. Inbasekaran, E. P. Woo, M. Soliman, Acta Polym., 49, 439, 1998.
[32] P. Blondin, J. Bouchard, S. Beaupre, M. Belletête, G. Durocher, M. Leclerc, Macromolecules, 33, 5874, 2000.
[33] G. Klaerner, R. D. Miller, Macromolecules, 31, 2007, 1998.
[34] J. -I. Lee, G. Klaerner, R. D. Miller, Chem. Mater., 11, 1083, 1999.
[35] G. Klärner, J. -I. Lee, V. Y. Lee, E. Chan, T. -P. Chen, A. Nelson, D. Markiewicz, R. Siemens, J. C. Scoot, R. D. Miller, Chem. Mater., 11, 1800, 1999
[36] J. -I. Lee, D. -H. Hwang, H. Park, L. -M. Do, H. Y. Chu, T. Zyung, R. D. Miller, Synthetic Metals, 111, 195, 2000
[37] T. Miteva, A. Meisel, W. Knoll, H. G. Nothofer, U. Scherf, D. C. Müller, K. Meerholz, A. Yasuda, D. Neher, Adv. Mater., 13, 565, 2001.
[38] X. Gong, P. K. Iyer, D. Moses, G. C. Bazan, A. J. Heeger, S. S. Xiao, Adv. Funct. Mater., 13, 325, 2003.
[39] L. Romaner, A. Pogantsch, P. S. Freitas, U. Scherf, M. Gaal, Q. Zojer, E. J. W. List, Adv. Funct. Mater., 13, 597, 2003.
[40] M. Gaal, E. J. W. List, U. Scherf, Macromolecules, 36, 4136, 2003.
[41] H. -O. Tang, M. Fujiki, M. Motonaga, Polymer, 43, 6213, 2002.
[42] H. -O. Tang, M. Fujiki, T. Sato, Macromolecules, 35, 6439, 2002.
[43] C. Xia, R. C. Advincula, Macromolecules, 34, 5854, 2001.
[44] W. -L. Yu, Y. Cao, J. Pei, W. Huang, A. J. Heeger, Appl. Phys. Lett., 75, 3270, 1999.
[45] W. -L. Yu, J. Pei, W. Huang, A. J. Heeger, Adv. Mater., 12, 828, 2000.
[46] A. Pogantsch, F. P. Wenzl, E. J. W. List, G. Leising, A. C. Grimsdale, K. Mullen, Adv. Mater., 14, 1061, 2002.
[47] J. S. Higgings, H. C. Benoit, Polymer and Neutron Scattering, Oxgord, New Tork, 1994.
[48] D. Hu et al., Nature, 405, 1030, 2000.
[49] J. P. Aime et al., Phys. Rev. Lett., 62, 55, 1989.
[50] G. Strobl, The Physics of Polymer, Springer-Verlag, Berlin, 1996