In the paper, two kinds of CdS nanorods with diameter of 50-150 nm were synthesized by using amphiphilic alanine as the templating reagent. XRD, TEM and polarized light microscopy were used to examine the course of CdS growth. The nanorod with a hexagonal pore microstructure was fabricated when the mesophase exhibited hexagonal morphology of the polarized light microscopy image. The XRD pattern of the nanorods with hexagonal pore microstructure showed a clear peak in 2θ=0.88° which suggested the existence of hexagonal pore. While the mesophase disappeared and isotropic polarized light microscopy image shows that CdS would propagate into nanorod without hexagonal pore. It was deduced that nanorods with hexagonal pore grow in the hole of hexagonal liquid crystal and those CdS growth without hexagonal pore are in isotropic solution by the absorption of amphilphilic alanine. It was suggested that different nanostructures could be generated under various chemical micro-environments to reveal their special functionalities.
Three azo-dyes, 4′-{[(2-hydroxylethyl)methyl]amino}-4-nitroazobenzene(1), 1-[4-(4′-nitrophenyl)-azophenyl]-3,5-biphenyl-2-pyrazoline(2) and 1-[4-(4′-nitrophenyl)-azophenyl]-5-(4′-hydroxylphenyl)-3-phenyl-2-pyrazoline(3) were synthesized. The polarized photoinduced birefringence and relaxation process of those azo-dyes doped with PMMA films were investigated under polarized laser intensity. The results indicate that compounds with pyrazoline group have a high storage rate and thermal stability. It has been found that the birefringence signals decrease with the increase of the temperature, but the effect of temperature is different for the three compounds. Compounds 2 and 3, with pyrazoline groups have a good thermal stability at room temperature, and compound 3 can even keep 30% of its maximum birefringence at 90 ℃.
Bifunctional pyrazoline derivatives 5 and 6 containing azobenzene group were prepared. The difference between them was the length of the flexible chain connecting the two chromophores. Compound 6 had four more methylenes than compound 5. UV\|Vis spectra of compounds 5 and 6 were the simple superposition of the absorbance of the azobenzene and pyrazoling and showed that pyrazoline had no effect on the isomerization of azobenzene. When there were two methylenes between azobenzene and pyrazoline, the fluorescent intensity of compound 5 decreased greatly compared with that of compound 6. It means that the intramolecular Electronic Energy Transfer has taken place in compound 5. In compound 6, this process could not occur because of the longer flexible chain between the two chromophores.
