| Budget Amount *help |
¥4,030,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥330,000)
Fiscal Year 2007: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2006: ¥2,600,000 (Direct Cost: ¥2,600,000)
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| Research Abstract |
Our ultimate goal is to control the transition between cubic (Cub) and smectic C (SmC) mesophases by external stimuli such as electric field or UV light. The system selected in this project is 1,2-bis (4'-n-alkoxybenzoyl) hydrazines (BABHs) with various alkyl chain lengths (n, where n is the number of carbon atoms in the alkyl chain and in this investigation varies from 4 to 22). To build a new molecular system responsive to UV light, binary mixtures of the BABH with 4,4'-n-alkoxyazobenzenes (AZO) were prepared and their phase behavior and response behavior to UV light irradiation were investigated. The following results were obtained:
1. First, we investigated the microstructure of the host compounds BABHs mainly by X-ray diffraction and infrared measurements. The n-temperature diagram was surveyed and two types of Cub phases with Ia3d (n = 5-13, 15-22) and Im3m (n = 13-16) symmetries were found; at a given temperature is seen the phase sequence of Ia3d -Im3m -Ia3d on going to larger n. The members with n = 13, 15, and 16 exhibit a Cub-to-Cub phase transition when temperature is varied.
2. From the packing study for the two Ia3d-Cub phases formed by shorter and longer chain members, we conclude that the BABH system provides a broad range of self-organization process from the low molecular mass liquid crystalline regime to the micro-segregation regime, and at the borderline between the two regimes the formation of the Im3m-Cub phase is realized.
3. Finally, for a BABH-AZO mixture with an optimized composition, we successfully observed a reversible photo-switching between the Ia3d-Cub and SmC phases.
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