A novel azobenzene SAM-LB composite film was fabricated by depositing LangmuirBlodgett monolayer of 4-octyl-4’ - (3-carboxy-trimethylene-oxy)-azobenzene (ABD) onto the cysteamine self-assembled monolayer(AET SAM) modified gold substrate. The film stability was greatly improved and the molecular aggregation was effectively prevented by the strong ionic bonding character on the SAM-LB interface, which was evidenced by both contact-angle titration, RA-FTIR and AFM. The reversible tran/cis isomerization and the clear-cut electrochemical response of cis-azobenzene were observed in the presence of highly organized molecular assemblies. This enable us to carry out a kinetic study of the cis-azobenzene in highly organized monolayers, by which a "more" reversible and unique pH dependent electron-transfer kinetic behavior of azobenzene was shown within the novel SAM-LB composite films.
The deprotonation of an amphiphilic porphyrin, meso-tetra (p-hydroxylphenyl)porphyrin with a hexadecyl chain(THPPH2), has been observed by means of UV-Visspectroscopy in CTAB micellar solutions. With increasing of PH values, the Soret band shiftsfrom 424 nm to 441nm, and the four-Q bands (520 nm, 560 nm, 595nm, 655 nm) aredisappeared while two new Q-bands are appeared at 585 nm and 675 nm, which is similar tometal-porphyrin, means that the deprotonation of porphyrin takes place. Comparing withthe spectra in an other solutions, the spectral characteration of THPPH2 in neutral and inbasic CTAB solutions is similar to that in CHCI3 and basic aqueous solutions respectively,suggesting that the solubilizing location of THPPH2 takes a change from inner to the outer of theCTAB micellars with the PH value of solutions increasing between 6. 20 and 11. 19.
