The formation kinetics of the self-assembled monolayer (SAM) of an azobenzenealkanethiol,denoted as AzoC2SH on surface was studied using electrochemical techniques,and the monolayers prepared at different assembly tim...The formation kinetics of the self-assembled monolayer (SAM) of an azobenzenealkanethiol,denoted as AzoC2SH on surface was studied using electrochemical techniques,and the monolayers prepared at different assembly times and concentration were also investigated.A two-step adsorption kinetics has been confirmed:the fast adsorption process and the following long-term reorganization.The equilibrium constant(K)for the adsorptioon and the interaction factor between adsorbate-adsorbate molecules () were evaluated based on the Frumkin isotherm and determined to be (3. 17±0. 13)× 106 mol.L(-1) and -0.34±0.04, respectively The Gibbs free energy (G)of SAM was determined to be -(37. 07±0. 13)kJ.mol(-1)展开更多
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) mod...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.展开更多
文摘The formation kinetics of the self-assembled monolayer (SAM) of an azobenzenealkanethiol,denoted as AzoC2SH on surface was studied using electrochemical techniques,and the monolayers prepared at different assembly times and concentration were also investigated.A two-step adsorption kinetics has been confirmed:the fast adsorption process and the following long-term reorganization.The equilibrium constant(K)for the adsorptioon and the interaction factor between adsorbate-adsorbate molecules () were evaluated based on the Frumkin isotherm and determined to be (3. 17±0. 13)× 106 mol.L(-1) and -0.34±0.04, respectively The Gibbs free energy (G)of SAM was determined to be -(37. 07±0. 13)kJ.mol(-1)
文摘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.
