A novel quinoline derivative 6-(10-thiol-decaoxy ) quinoine (abbreviated as QC10SH )was synthesized and its seif-assembled monoayers (SAMs) were prepared on gold for the first time. Wettability measurement on QC10SH S...A novel quinoline derivative 6-(10-thiol-decaoxy ) quinoine (abbreviated as QC10SH )was synthesized and its seif-assembled monoayers (SAMs) were prepared on gold for the first time. Wettability measurement on QC10SH SAM reveals a hydrophilic surface. RA-IR researches suggests that the SAM has formed highly-organized and closely-packed structure. A method is developed for quanitatively evaluating the molecular orientation in monoayer. By this method the result that the twisting and tilting angles of QC10SH moecule in SAM are 50±4° and 24±3°respectively has been obtained.展开更多
AFM was employed for fabricating positive organic pattern on gold surface. In this procedure, 1-octadecanethiol was adsorbed onto AFM tip firstly and then transported to gold surface during the scanning process. The t...AFM was employed for fabricating positive organic pattern on gold surface. In this procedure, 1-octadecanethiol was adsorbed onto AFM tip firstly and then transported to gold surface during the scanning process. The transported molecules could spontaneously adsorbed onto gold surface to form a monolayer. The selective transport was controlled by the scanning parameter, such as scanning speed and tip-substrate interaction. It was found that the relative humidity plays very important roles on the deposition process, the higher the humidity, the higher the possibility that deposition happens. The dependence of deposition on the humidity suggests that the 1-octadecanethiol molecule is transported through the water layer on the gold surface. Meanwhile, the optimal deposition condition also depends on the characteristics of AFM tip.展开更多
Self Assembled Monolayers(SAMs) of a series of mercapto contained azobenzene derivatives with the structure of C n H 2 n +1 AzoO(CH 2) m SH (where n =4,6,8,10,12; with m =3,5 respectively) were prepared and characteri...Self Assembled Monolayers(SAMs) of a series of mercapto contained azobenzene derivatives with the structure of C n H 2 n +1 AzoO(CH 2) m SH (where n =4,6,8,10,12; with m =3,5 respectively) were prepared and characterized.Wettability measurement of water on the SAMs demonstrates that molecular packing density in the monolayers increases while the alkyl chain in the molecules is lengthened. Both the n and m values have similar contribution to the wetting property of SAMs. The RA IR spectra reveal that the alkyl chains in the SAMs tilt away dramatically from the surface normal direction with the increase in their length. However, the orientation of azobenzene moiety is found to be influenced slightly by the alkyl chain length, which is due to the tenderness of the molecule.展开更多
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
The end-group dominated molecular orientation in the azobenzene self-assembled monolayers (SAMs), CnAzoC2SH (n=1-4), on gold was evaluated for the first time by grazing incidence reflection absorption FTIR spectroscop...The end-group dominated molecular orientation in the azobenzene self-assembled monolayers (SAMs), CnAzoC2SH (n=1-4), on gold was evaluated for the first time by grazing incidence reflection absorption FTIR spectroscopy (RA-FTIR). All these azobenzene SAMs have highly-organized and closely-parked structures, with the molecule tilting away gradually from surface normal direction with the increase of end group alkyl length.展开更多
美国化学会（The American Chemical Society。ACS）是当今世界上化学领域影响最大的专业组织，成立于1876年。现有会员超过158000位，分属于33个涵盖与化学化工相关的不同领域的分会。美国化学会每年举行两次涵盖化学各方向的年会，并...美国化学会（The American Chemical Society。ACS）是当今世界上化学领域影响最大的专业组织，成立于1876年。现有会员超过158000位，分属于33个涵盖与化学化工相关的不同领域的分会。美国化学会每年举行两次涵盖化学各方向的年会，并有许多规模稍小的专业研讨会。展开更多
Mutual coupling of surface electromagnetic wave between different silver particles onsilver island substrates is realized experimentally and its effect on surface enhanced infrared spec-troscopy is studied. Silvcr isl...Mutual coupling of surface electromagnetic wave between different silver particles onsilver island substrates is realized experimentally and its effect on surface enhanced infrared spec-troscopy is studied. Silvcr island substrates of different size and distribution of silver particleshave been prepared by the vacuum evaporation and rapid thermal annealing, and characterizedby atomic force microscopy (AFM) and UV-visiblc spectroscopy. The surface enhanced infraredspectra of 4-Octyl-4’-(3-carboxy-trimethylene -oxy)-azobenzene (referred as ABD) LB monolayerare studied on such silver island films. The results elucidates the important role of the coupling ofsurface electromagnetic wave between silver particles in surface enhanced infrared spectroscopy.展开更多
文摘A novel quinoline derivative 6-(10-thiol-decaoxy ) quinoine (abbreviated as QC10SH )was synthesized and its seif-assembled monoayers (SAMs) were prepared on gold for the first time. Wettability measurement on QC10SH SAM reveals a hydrophilic surface. RA-IR researches suggests that the SAM has formed highly-organized and closely-packed structure. A method is developed for quanitatively evaluating the molecular orientation in monoayer. By this method the result that the twisting and tilting angles of QC10SH moecule in SAM are 50±4° and 24±3°respectively has been obtained.
文摘AFM was employed for fabricating positive organic pattern on gold surface. In this procedure, 1-octadecanethiol was adsorbed onto AFM tip firstly and then transported to gold surface during the scanning process. The transported molecules could spontaneously adsorbed onto gold surface to form a monolayer. The selective transport was controlled by the scanning parameter, such as scanning speed and tip-substrate interaction. It was found that the relative humidity plays very important roles on the deposition process, the higher the humidity, the higher the possibility that deposition happens. The dependence of deposition on the humidity suggests that the 1-octadecanethiol molecule is transported through the water layer on the gold surface. Meanwhile, the optimal deposition condition also depends on the characteristics of AFM tip.
文摘Self Assembled Monolayers(SAMs) of a series of mercapto contained azobenzene derivatives with the structure of C n H 2 n +1 AzoO(CH 2) m SH (where n =4,6,8,10,12; with m =3,5 respectively) were prepared and characterized.Wettability measurement of water on the SAMs demonstrates that molecular packing density in the monolayers increases while the alkyl chain in the molecules is lengthened. Both the n and m values have similar contribution to the wetting property of SAMs. The RA IR spectra reveal that the alkyl chains in the SAMs tilt away dramatically from the surface normal direction with the increase in their length. However, the orientation of azobenzene moiety is found to be influenced slightly by the alkyl chain length, which is due to the tenderness of the molecule.
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The end-group dominated molecular orientation in the azobenzene self-assembled monolayers (SAMs), CnAzoC2SH (n=1-4), on gold was evaluated for the first time by grazing incidence reflection absorption FTIR spectroscopy (RA-FTIR). All these azobenzene SAMs have highly-organized and closely-parked structures, with the molecule tilting away gradually from surface normal direction with the increase of end group alkyl length.
文摘Mutual coupling of surface electromagnetic wave between different silver particles onsilver island substrates is realized experimentally and its effect on surface enhanced infrared spec-troscopy is studied. Silvcr island substrates of different size and distribution of silver particleshave been prepared by the vacuum evaporation and rapid thermal annealing, and characterizedby atomic force microscopy (AFM) and UV-visiblc spectroscopy. The surface enhanced infraredspectra of 4-Octyl-4’-(3-carboxy-trimethylene -oxy)-azobenzene (referred as ABD) LB monolayerare studied on such silver island films. The results elucidates the important role of the coupling ofsurface electromagnetic wave between silver particles in surface enhanced infrared spectroscopy.
