本論文主要經由對奈米薄膜不穩除潤過程的精細觀察，量測共軛高分子薄膜內部的分子鏈反彈應力(molecular recoiling stress)，並據以探究高分子從溶液旋塗成固態薄膜的演變與分子堆積情形。本研究
所使用的共軛高分子為(poly[2-methoxy-5-((2’-ethylhexyl)oxy)-1,4-phenylenevinylene]) MEH-PPV，並輔以非共軛結構之高分子聚苯乙烯(polystyrene，PS)。我們經由量測奈米薄膜除潤時，在初期孔洞邊緣的應力釋放，以及在複層結構時對彈性基材的彈性形變，發現共軛高分子薄膜有較小的分子應力，此可能與硬桿型分子結構所具有較長的分子堅持長度（Persistence length）和較小的分子亂度有關。此外，在旋塗形成薄膜時，共軛高分子由於硬桿結構，較不易形成阻礙溶劑逸散的表皮層(skin layer)，因此，其分子應力對薄膜厚度，呈現單一的指數下降現象，而非一般非共軛高分子的雙指數下降行為。同時，共軛高分子奈米薄膜在旋塗基材寬約2nm的介面層，也有遠較非共軛高分子為小的堆積密度(約為十分之一)，此應與旋塗成形時，溶劑揮發造成的分子反彈力較小有關。最後，由於高分子強大的聲子-電子交互作用(electron-phonon coupling)，共軛高分子的光電發光效率其實與分子鏈段應力(Segmental stress)密切相關，此薄膜成形時所產生的殘留應力，與高分子光電元件的性能密切相關。

The thesis aims to measure the molecular stresses operative in conjugated polymer molecules and explore their packing in the ultrathin films prepared by spin coating. The conjugated polymer MEH-PPV (poly[2-methoxy-5-((2’-ethylhexyl)oxy)-1,4-phenylenevinylene]) was used as the model polymer in comparison to the non-conjugated polymer polystyrene (PS). The molecular stresses were determined from the thin film instability of dewetting, by measuring the stress release at the edge of an incipient hole or the depression in the soft elastic substrate underneath a dewetting hole. The molecular stresses of the conjugated polymer confined in thin films were found substantially smaller than those of PS. The observation is attributed to the rigid-rod molecular structure that exhibits a longer persistence length and hence a smaller entropy variation for the transition of the molecules from solute to solid film. In addition, the local mass density in the thin (~2nm) interfacial layer next to the substrate was found to be only one tenth of that of PS, believably resulted from the smaller molecular recoiling forces during solvent evaporation. Moreover, in contrast to the double-exponential behavior of flexible-chain polymers such as PS, the molecular stress demonstrated a single exponential decay with film thickness, indicating the absence of skin layer during the rapid solidification of spin coating, which is also attributed to the rigid-rod structure that allows easier passing of the solvent molecules. Since the optoelectronic quantum efficiencies are highly dependent on the segmental stress due to the robust electron-phonon interactions of the linear chains, good control over the residual stress of thin conjugated polymer films plays a fundamental role for the development of polymer-based devices.

[1] K.-P. Tung, C.-C. Chen, P.-W. Lee, Y.-W. Liu, T.-M. Hong, K.-C.
Hwang, K.C. Hsu , J.H. White, D. Jonathan, A. C.− M. Yang, ACS
nano, 2011. 5(9): p. 7296-7302.
[2] G. Reiter, M. Hamieh, P. Damman, S. Sclavons, S. Gabriele,T. Vilmin, A.E. Raphaël, Nature Materials 2005, 4, 754-758.
[3] M. H. Yang, S. Y. Hou, Y. L Chang, A. C.-M.Yang, Physical Review Letters, 2006, 96, 066105.
[4] G. Reiter, Physical Review Letters, 1992, 68, 75-78.
[5] G. Reiter, Langmuir, 1993. 9, 1344-1351.
[6]Vrij, A., & Overbeek, J. T. G., Journal of the American Chemical Society, 90(12), 3074-3078. (1968).
[7] J. W. Cahn, J. Chem. Phy., 1965, 42, 93.
[8] M. Sferrazza, C. Xiao, R.A.L. Jones, D.G. Bucknall, J. Webster, J. Penfold, Phys. Rev. Lett. 1997, 78, 3693.
[9] T. Vilmin and E. Raphael, Europhy. Lett. 2005, 72, 781.
[10] S. A. Akhrass, G. Reiter, S. Y. Hou, M. H. Yang, Y. L. Chang, F. C. , C. F. Wang, A. C.-M. Yang, Phys. Rev. Lett. 2008, 100, 178301.
[11] G. Reiter, P.G. de Gennes, The European Physical Journal E, 2001, 6, 25-28.
[12] G. Reiter, Macromolecules ,1994, 27, 3046-3052.
[13] M.H. Yang, S. Y. Hou, Y. L. Chang, A.C.-M. Yang, Phys. Rev. Lett., 2006,96, 066105.
[14] R. Seemann, S. Herminghaus and K. Jacobs, Phys. Rev. Lett., 2001, 86, 5534–5537.
[15] A. Sharma, Langmuir, 1993, 9, 861.
[16] A. Sharma, Langmuir, 9, 3580 (1993).
[17] R. Seemann, , S. Herminghaus, and K. Jacobs, Phys. Rev. Lett., 2001. 86: p. 5534.
[18] L. Rayleigh, Proc. London Math. Soc., 1978, 10, 4.
[19] K. Jacobs, S. Herminghaus, and K.R. Mecke, Langmuir, 1998, 14, 965.
[20] G. Reiter, Phy. Rev. Lett., 1922, 68, 75.
[21] R. Xie, A. Karim, J.F. Douglas, C.C. Han, R.A. Weiss, Phys. Rev. Lett., 1998, 81, 1251-1254
[22] T. G. Stange and D. F. Evans, Langmuir, 1997, 13, 4459.
[23] G. Reiter, Advances in Polymer Science 2013, 252, 29-64.
[24] K.Y. Suh and H.H. Lee, Phys. Rev. Lett., 2001, 87, 135502.
[25] A. Sharma and J. Mittal, Phys. Rev. Lett., 2002, 89, 186101.
[26] M. Sferrazza et al., Phys. Rev. Lett., 1998, 81, 5173.
[27] T.G. Stange, D.F. Evans, W.A. Hendrickson, Langmuir, 1997, 13, 4459-4465.
[28] 簡毅, 清華大學材料系碩士論文 2011,高分子超薄膜分子拘束造成機械不穩態、發光行為變異、和楊氏係數下降之研究
[29] P. F. Barbara, A. J. Gesquire, S.-J. Park, Y. J. Lee, Acc. Chem. Res., 2005, 38, 602.
[30] J. Yu, D. Hu, P. F. Barbara, Science, 2000, 289, 1327.
[31] J. C. Bolinger, M. C. Traub, T. Adachi, P. F. Barbara, Science, 2011, 331, 4
[32] J. Shinar and J. Partee, Syn. Met.,1997, 84, 525-528.
[33] L. J. Rothberg, M. Yan, S. Son, M. E. Galvin, E.W. Kwock, T. M.
Miller, H. E. Katz, R. C. Haddon, F. Papadimitrakopoulos, Syn.
Met., 1996, 78, 213-216.
[34] T. W. Lee and O. O. Park, Adv. Mater., 2000, 12, 11.
[35] T. Q. Nguyen, I. B. Martini, J. Liu, and B. J. Schwartz, J. Phys.
Chem. B, 2000, 104, 237-255.
[36] H. J. Chen, L. Y. Wang, W. Y. Chiu, Eur. Poly. J.,2007, 43, 4750–4761.
[37] J. Liu, T. F. Guo, and Y. Yang, Appl. Phys. Lett.,2002, 91, 3.
[38]楊志偉,清華大學材料系碩士論文 2006, 利用除潤與薄膜拉伸測試研究分子鏈運動對共軛高分子發光之影響
[39]張昱崙, 清華材料系碩士論文2006, 拘束於旋塗奈米超薄脅內的高分子團之分子力、堆積、和形變量測與分析研究
[40]陳炳志,清華大學材料系碩士論文 2010, 表面除潤摩擦形變引起之共軛高分子巨大之光電增益
[41]李培煒, 清華大學材料系碩士論文 2011, 共軛高分子薄膜之分子堆積、除潤運動與拉伸的發光增益研究.
[42] X. Yang and J. Loos, Macromolecules 40, 1353 (2007).
[43] D. E. Markov, E. Amsterdam, P. W. M. Blom, A. B. Sieval, and J. C.
Hummelen, J. Phys. Chem. A, 109, 5266 (2005).
[44] J. J. M. Halls, K. Pichler, R. H. Friend, S.C. Moratti, and A. B.
Holmes, Appl. Phys. Lett. 68, 3120 (1996).
[45] D. E. Markov, C. Tanase, P. W. M. Blom, and J. Wildeman, Phys.
Rev. B, 72, 045217 (2005)
[46] T. Q. Nguyen, V.Doan, B. J. Schwartz, Journal of Chemical Physics 1999, 110, 4068.
[47] E. Collini, G. D. Scholes , Science 2009, 323, 369-373.
[48] T. Q. Nguyen, J. Wu, V. Doan, B. J. Schwartz, S. H.Tolbert, Science 2000, 288, 652-656.
[49] J. Vogelsang, T.Adachi, J .Brazard, D. A. Vanden Bout, P. F. Barbara, Nature Materials 2011, 10, 942-946.
[50] J. Vogelsang, J. Brazard, T. Adachi, J. C.Bolinger, , P. F. Barbara, , Angewandte Chemie International Editon 2011, 50, 2257-2261.
[51] J. L. Brédas, R. Silbey, Science 2009, 323, 348-349.
[52] B. J. Schwartz, Annual Review of Physical Chemistry 2003, 54, 141-172.
[53] B. J. Schwartz, Nature Materials 2008, 7, 427-428.
[54] M. Rubinstein and R.H. Colby, Polymer physics. 2003: Oxford
University Press, New York.
[55] A. R. Khokhlov , A.Y. Grosberg, V. S. Pande, Statistical Physics of Macromolecules (Polymers and Complex Materials): American Institute of Physicsm (1994)
[56] A. Brûlet, F. Boué, and J. P. Cotton. ,Journal de Physique II 6.6 (1996): 885-891.
[57] Su, C. H., et al. Macromolecules 42.17 (2009): 6656-6664.
[58] C. L. Gettinger, A. J. Heeger, J. M. Drake & D. J. Pine, Molecular Crystals and Liquid Crystals 1994, 256(1), 507-512.
[59] V.-D Tuan, Nanotechnology in Biology and Medicine. Methods, Devices, and Applications, Boca Raton : CRC Press (2007), pp.257
[60] Inigo, A. R., et al., Journal of the Chinese Chemical Society 57.3B
(2010): 459-468.
[61] de Gennes, P.-G., The journal of chemical physics 55.2 (1971): 572.