Macromolecules
ARTICLE
Upon heating, the SmB-like packing of side-chains transforms
into a SmA-like structure followed by a transition of SmA-to-
isotropic. We also observe that the confinement effect can greatly
enhance the thermal stability of the SmA-like packing of azo-
benzene moiety. We compare the phase behaviors between
P1 and a conventional SCLCP (P2) with one azobenzene group
per repeating unit. P2 just form a monolayer SmA phase at low
temperatures, and its transition temperatures are much lower
than that of P1. This comparison verifies that the main-chain
scaffold confinement effect is important for the azobenzene side-
chain packing in P1. As P1 exhibit a fascinating hierarchical
ordering, we are also interested in investigating how the supra-
molecular structure will influence the photoresponsive behavior
of azobenzene group or vice versa. Our preliminary result shows
that P1 remains its LC property under UV irradiation, in contrast
to that P2 can become completely isotropic. The UV-induced LC
phase of P1 might be a ΦN phase, reflecting the existence of rod-
like main-chains. More researches on the photoinduced anisot-
ropy and photochemical phase transition of P1 are ongoing and
will be reported later.
(11) Jin, S.; Jeong, K. U.; Tu, Y.; Graham, M. J.; Wang, J.; Harris,
F. W.; Cheng, S. Z. D. Macromolecules 2007, 40, 5450–5459.
(12) Zentel, R.; Brehmer, M. Acta Polym. 1996, 47, 141–149.
(13) Reck, B.; Ringsdorf, H. Makromol. Chem. 1985, 6, 291–299.
(14) Reck, B.; Ringsdorf, H. Makromol. Chem. 1986, 7, 389–396.
(15) Cooray, N. F.; Fujimoto, H.; Kakimoto, M.-a.; Imai, Y. Macro-
molecules 1997, 30, 3169–3174.
(16) Ge, J. J.; Zhang, A. Q.; McCreight, K. W.; Ho, R. M.; Wang,
S. Y.; Jin, X. M.; Harris, F. W.; Cheng, S. Z. D. Macromolecules 1997,
30, 6498–6506.
(17) Huang, W.; Han, C. D. Macromolecules 2006, 39, 4735–4745.
(18) Joo, S.-H.; Yun, Y.-K.; Jin, J.-I.; Kim, D.-C.; Zin, W.-C. Macro-
molecules 2000, 33, 6704–6712.
(19) Lam, J. W. Y.; Tang, B. Z. Acc. Chem. Res. 2005, 38, 745–754.
(20) Piao, X. L.; Kim, J.-S.; Yun, Y.-K.; Jin, J.-I.; Hong, S.-K.
Macromolecules 1997, 30, 2294–2299.
(21) Ruan, J. J.; Jin, S.; Ge, J. J.; Jeong, K. U.; Graham, M. J.; Zhang,
D.; Harris, F. W.; Lotz, B.; Cheng, S. Z. D. Polymer 2006, 47, 4182–4193.
(22) Schaefer, K. E.; Keller, P.; Deming, T. J. Macromolecules 2006,
39, 19–22.
(23) Zhou, M.; Han, C. D. Macromolecules 2005, 38, 9602–9609.
(24) Xie, H.; Hu, T.; Zhang, X.; Zhang, H.; Chen, E.; Zhou, Q.
J. Polym. Sci. Part A: Polym. Chem 2008, 46, 7310–7340.
(25) Chen, X.-F.; Shen, Z.; Wan, X.-H.; Fan, X.-H.; Chen, E.-Q.; Ma,
Y.; Zhou, Q.-F. Chem. Soc. Rev. 2010, 39, 3072–3101.
(26) Zhou, Q. F.; Li, H. M.; Feng, X. D. Macromolecules 1987, 20,
233–234.
’ ASSOCIATED CONTENT
S
Supporting Information. Materials and experimental de-
b
tails, and figures showing GPC curves of P1 with different MWs,
1H NMR spectra of M2 and P2, POM images of P2, and 1D and
2D WAXD patterns of P2. This material is available free of charge
(27) Zhou, Q. F.; Zhu, X. L.; Wen, Z. Q. Macromolecules 1989,
22, 491–493.
(28) Chen, X. F.; Tenneti, K. K.; Li, C. Y.; Bai, Y. W.; Zhou, R.; Wan,
X. H.; Fan, X. H.; Zhou, Q. F. Macromolecules 2006, 39, 517–527.
(29) Gopalan, P.; Andruzzi, L.; Li, X.; Ober, C. K. Macromol. Chem.
Phys. 2002, 203, 1573–1583.
(30) Gray, G. W.; Hill, J. S.; Lacey, D. Mol. Cryst. Liq. Cryst. 1991,
197, 43–55.
(31) Hessel, F.; Herr, R. P.; Finkelmann, H. Makromol. Chem. 1987,
188, 1597–1611.
(32) Keller, P.; Hardouin, R.; Mauzac, M.; Achard, M. Mol. Cryst. Liq.
Cryst. 1998, 155, 71–80.
’ AUTHOR INFORMATION
Corresponding Author
*E-mail: hailiangzhang@xtu.edu.cn (H.-L.Z.); eqchen@pku.edu.
cn (E.-Q.C.).
(33) Percec, V.; Tomazos, D. J. Matter. Chem. 1993, 3, 643–650.
(34) Pragliola, S.; Ober, C. K.; Mather, P. T.; Jeon, H. G. Macromol.
Chem. Phys. 1999, 200, 2338–2344.
(35) Pugh, C.; Schrock, R. R. Macromolecules 1992, 25, 6593–6604.
(36) Xu, Y.; Yang, Q.; Shen, Z.; Chen, X.; Fan, X.; Zhou, Q.
Macromolecules 2009, 42, 2542–2550.
(37) Ye, C.; Zhang, H. L.; Huang, Y.; Chen, E. Q.; Lu, Y. L.; Shen, D. Y.;
Wan, X. H.; Shen, Z. H.; Cheng, S. Z. D.; Zhou, Q. F. Macromolecules 2004,
37, 7188–7196.
(38) Yin, X. Y.; Ye, C.; Ma, X.; Chen, E. Q.; Qi, X. Y.; Duan, X. F.;
Wan, X. H.; Cheng, S. Z. D.; Zhou, Q. F. J. Am. Chem. Soc. 2003, 125,
6854–6855.
’ ACKNOWLEDGMENT
This work is supported by the National Natural Science
Foundation of China (NNSFC Grants: 20874082, 20990232,
21074003, and 51073131), the Natural Science Foundation of
Xiangtan University (No: 10XZX09) and Hunan Provincial
Natural Science Foundation of China (No: 11JJ4012).
’ REFERENCES
(1) Blumstein, A. Polymeric Liquid Crystals; Plenum Press: New York,
1985.
(39) Xie, H. L.; Jie, C. K.; Yu, Z. Q.; Liu, X. B.; Zhang, H. L.; Shen,
Z. H.; Chen, E. Q.; Zhou, Q. F. J. Am. Chem. Soc. 2010, 132, 8071–8080.
(40) Cojocariu, C.; Rochon, P. Macromolecules 2005, 38, 9526–9538.
(41) Freiberg, S.; Lagugne-Labarthet, F.; Rochon, P.; Natansohn, A.
Macromolecules 2003, 36, 2680–2688.
(42) Li, M. H.; Auroy, P.; Keller, P. Liq. Cryst. 2000, 27, 1497–1502.
(43) Mao, G. P.; Wang, J. G.; Clingman, S. R.; Ober, C. K.; Chen,
J. T.; Thomas, E. L. Macromolecules 1997, 30, 2556–2567.
(44) Wolff, D.; Cackovic, H.; Kruger, H.; Rubner, J.; Springer, J. Liq.
Cryst. 1993, 14, 917–928.
(45) Del Barrio, J.; Oriol, L.; Sanchez, C.; Serrano, J. L.; Di Cicco, A.;
Keller, P.; Li, M. H. J. Am. Chem. Soc. 2010, 132, 3762–3769.
(46) Deng, W.; Albouy, P. A.; Lacaze, E.; Keller, P.; Wang, X. G.; Li,
M. H. Macromolecules 2008, 41, 2459–2466.
(47) Deng, W.; Li, M. H.; Wang, X. G.; Keller, P. Liq. Cryst. 2009,
36, 1023–1029.
(2) Mcardle, C. B. Side Chain Liquid Crystal Polymers; Blackie and
Son Ltd: Glasgow, U.K., 1989.
(3) Percec, V.; Pugh, C. Side Chain Liquid Crystal Polymers; MacArdle,
C. B., Ed: Blackie: Glasgow, U.K., 1989.
(4) Simmonds, D. J. Liquid Crystal Polymers, From Structures to
Applications; Elsevier Applied Science: London and New York, 1992.
(5) Mao, G.; Ober, C. K. Acta Polym. 1997, 48, 405–422.
(6) Maughon, B. R.; Weck, M.; Mohr, B.; Grubbs, R. H. Macro-
molecules 1997, 30, 257–265.
(7) Nieuwhof, R. P.; Koudijs, A.; Marcelis, A. T. M.; Sudh€olter,
E. J. R. Macromolecules 1999, 32, 6499–6506.
(8) Percec, V.; Tomazos, D.; Willingham, R. A. Polym. Bull. 1989,
22, 199–206.
(9) Ranganathan, T.; Bhoje Gowd, E.; Ramesh, C.; Kumar, A.
J. Polym. Sci. Part A: Polym. Chem 2005, 43, 1903–1912.
(10) Watanabe, J.; Ono, H.; Uematsu, I.; Abe, A. Macromolecules
1985, 18, 2141–2148.
(48) Yu, Y. L.; Ikeda, T. Angew. Chem. Int. Ed 2006, 45, 5416–5418.
7608
dx.doi.org/10.1021/ma200851v |Macromolecules 2011, 44, 7600–7609