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 changes in photoluminescence and FTIR spectra of porous silicon subjected to oxidation were exdrined. With the increase of okidizing duxation, the relative amount of the Si-H2 surface species on PS decreases even though the photoluminescence intensity increases. the result suggests that it isn’t SiH2 but Si-O and Si-O-Si on theinterface of PS play a key role in enhancing the pllotoluminescence. A complete photoluminescence mechanism should consider the influence of su-rface state of porous silicon based on the quantum codriement effect model.
