Photo-induced isomerization of poly 4′-(6-acryloxy) hexyloxy-4-methoxyazobenzene ultra-thin solid film prepared by Langmuir？Blodgett technique

다국어 초록 (Multilingual Abstract)

The photo-induced response of an ultra thin polymeric lm of poly 40-(6-acryloxy) hexyloxy-4-methoxyazobenzene (P5) is investi-gated. A monolayer of P5 at a gaswater interface possesses a mean molecular area of 28.0 A˚2/monomer-repeat. Multilayer lms ofP5 were prepared by horizontal deposition at a surface pressure of 25 mN/m2. The uniformity of the transfer process is shown byUVvis absorption spectra where a linear relationship between the absorption maxima and the number of transferred layer was observed.The average layer thickness of the transferred lm determined by XRD measurements is 34.0 A˚. This is longer than the length of theazobenzene side group. The transferred lm shows a blue shift of thepp* transition from 357 nm for the P5 in solution to 340 nmfor the P5 in the lm. This suggests the formation of H-aggregate with a head-to-head arrangement of the dipole within the lm.The optical property of the transferred lm is changed by the irradiation of the lm with the UV light at 385 nm. An irreversible changein its molecular packing in the lm is seen in the shift of the UVvis absorption maxima and the change in morphology as observed byAFM. The lm morphology changes from being a smooth lm into an island-like surface when exposed to the UV irradiation. The layercistransthermal back isomerization process. This suggeststhat movement of the P5 took place in both thetranscisisomerization process and thecistransback isomerization process. The rstmovement leads to a molecular expansion while the second, to a molecular contraction.

참고문헌 (Reference)

1 P. Rochon, 66 : 136-, 1995

2 N. Kawatsuki, 19 : 151-, 2006

3 A. Natansohn, 102 : 4139-, 2002

4 K. Ichimura, 100 : 1847-, 2000

5 S. Bian, 89 : 4498-, 1999

6 G.S. Kumar, 89 : 1915-, 1989

7 X. Hou, 58 : 369-, 2004

8 N.K. Viswanathan, 102 : 6064-, 1998

9 M. Liu, 101 : 1101-, 1997

10 M. Kameda, 88 : 2068-, 2003

11 T. Seki, 15 : 5098-, 1999

12 T. Ubukata, 107 : 13831-, 2003

13 P. Kasemjit, 41 : 4017-, 2003

14 T. Srikhirin, 77 : 963-, 2000

15 H.C. Yoon, 137 : 1424-, 2003

16 S. Sortino, 14 : 811-, 2004

17 S.H. Ou, 61 : 2284-, 1992

18 S.H. Ou, 10 : 905-, 1994

19 R. Wuestneck, 198 : 753-, 2002

20 I. Kim, 171 : 167-, 2000

21 R.F. Nieuwhof, 17 : 78-, 2001

22 T. Seki, 76 : 2217-, 2003

23 J. Hagting, "Langmuir–Blodgett Films of Poly(p-phenylenevinylene) Precursor Polymers. ISBN 90-367-1100-2 (Chapter 3)"