Phase Structure and Phase Transition Mechanism for Light-Induced Ia3d Cubic Phase in 4鈥?n-Docosyloxy-3鈥?nitrobiphenyl-4-carboxlic acid/Ethyl 4-(4鈥?n-docosyloxyphenylazo)ben

详细信息    查看全文

• 作者：Ryo Hori ; Yohei Miwa ; Katsuhiro Yamamoto ; Shoichi Kutsumizu
• 刊名：Journal of Physical Chemistry B
• 出版年：2014
• 出版时间：April 3, 2014
• 年：2014
• 卷：118
• 期：13
• 页码：3743-3749
• 全文大小：392K
• 年卷期：v.118,no.13(April 3, 2014)
• ISSN：1520-5207

文摘

The light-induced smectic C (SmC) to bicontinuous cubic (Cub_bi) phase transition was investigated using grazing-incidence X-ray diffraction (GI-XRD) and Fourier transform infrared (FT-IR) spectroscopy to elucidate the mechanism at the molecular level. The sample was a binary mixture of 4鈥?n-docosyloxy-3鈥?nitrobiphenyl-4-carboxylic acid with an azobenzene derivative having a similar structure. The GI-XRD analysis revealed that the lattice size of the light-induced Cub_bi phase almost coincides with the extrapolated value of the thermally induced one to the irradiation temperature. The FT-IR analysis also showed that the UV irradiation shifts the peak positions toward their extrapolated wavenumbers that would be displayed by the thermally induced Cub_bi phase at the temperature. These results indicate that both the molecular state and periodic structure realized by the irradiation may be regarded as the 鈥減ostulated鈥?state and periodic structure of thermally induced Cub_bi phase at the temperature. This leads to a conclusion that the trans鈥?i>cis photoisomerization of the azobenzene derivatives in the mixture gives rise to destabilization of the SmC phase with layered structure, alternatively favoring the formation of the Cub_bi phase with a twisted molecular arrangement.