Four ＂picket fence＂ porphyrin atropisomers were respectively synthesized from the four corresponding atropisomers of meso-tetra（o-aminophenyl）porphyrin that had been chromatographed on a column eluted with petrole...Four ＂picket fence＂ porphyrin atropisomers were respectively synthesized from the four corresponding atropisomers of meso-tetra（o-aminophenyl）porphyrin that had been chromatographed on a column eluted with petroleum ether and ethyl acetate. Results show that each atropisomer could be successfully synthesized by controlling the acylation temperature at 0 ℃. They were characterized by 1H NMR, HRMS, IR, UV-Vis and Langmuir-Blodgett（LB） film analyses. Although the results of HRMS, IR, UV-Vis analyses indicate there is no remarkable difference among the atropisomers, the results of the 1H NMR and the mean molecular areas obtained by LB film technique imply that the atropisomers are significantly discrepant. The former shows that the chemical shifts of the methyl and amide protons of each atropisomer are distinct, while the later presents that the different atropisomer molecules can occupy the different surface areas at the air/water interface.展开更多
Mixed Stearic acid and poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS) Langmuir- Blodgett(LB) films were successfully fabricated by the conventional vertical dipping method.Stearic acid and PEDOT...Mixed Stearic acid and poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS) Langmuir- Blodgett(LB) films were successfully fabricated by the conventional vertical dipping method.Stearic acid and PEDOT/PSS was dissolved in chloroform and spread on subphase containing 0.04wt% FeCl_3.Conductive Y-type mixed LB films was successfully prepared under the condition of surface pressure with 30 mN/m,pH 3.8,and 19℃.UV-VIS spectrum showed that well ordered layer-by-layer fabrication of mixed films were obtained and thickness of single layer film with about 5 nm was evaluated.The morphology image of mixed LB film was observed by atomic force microscopy (AFM).The conductivity of mixed LB film was about 1.8×10^(-5)S/cm and the film showed sensitivity to NH_3 at the same time.展开更多
An arachidic acid/poly （3, 4-ethylene dioxythiophene） （AA/PEDOT） multilayer Langmuir-Blodgett （LB） film was prepared by a modified LB film method. The theories were utilized to explain the effects between HCl mo...An arachidic acid/poly （3, 4-ethylene dioxythiophene） （AA/PEDOT） multilayer Langmuir-Blodgett （LB） film was prepared by a modified LB film method. The theories were utilized to explain the effects between HCl molecule and LB film. The gas sensitivity mechanism of poly （3, 4-ethylene dioxythiophene） （PEDOT） multilayer film can be explained by the charge transfer between p system of PEDOT and oxidization HCl system. The gas sensitivity of PEDOT LB film deposited interdigital electrode to HCl was tested. The results showed that film thickness, treating temperature, deposition speed had different influence on film gas sensitivity. The AA/PEDOT film deposited device exhibited nonlinear behavior to HCl gas at lower concentration （20-60 ppm） and linear response behavior at higher gas concentration was observed. The time of the compound LB film of the AA/PEDOT responding to the 30 ppm HCl gas is about 20 seconds, which is far quicker than the time of the film to the PEDOTPRESS film（about 80 seconds）. It is not higher film press to better film. When the film press attains 45 mNs/m, the sensitivity of the AA/PEDOT film on the contrary descends.展开更多
The surface morphologies of polyimide LB film and the SiC film pyrolyzed from polyimide LB film were studied with STM technique. The results show that molecular chains of polyimide LB film are highly oriented in certa...The surface morphologies of polyimide LB film and the SiC film pyrolyzed from polyimide LB film were studied with STM technique. The results show that molecular chains of polyimide LB film are highly oriented in certain scale, the SiC film keeps the similar regular structure to that of polyimide LB film, suggesting that the SiC formation reaction proceeds on the basis of the lattice of polyimide molecules.展开更多
A bolaform （BNC10） and single-headed （HNOA） amphiphilic Schiff bases containing naphthyl group were designed and their Langmuir-Blodgett films were investigated. It was found that both the LB films show acidichrom...A bolaform （BNC10） and single-headed （HNOA） amphiphilic Schiff bases containing naphthyl group were designed and their Langmuir-Blodgett films were investigated. It was found that both the LB films show acidichromism, i.e. a reversible color change upon alternatively exposing the films to HC1 and NH3 gases, respectively. It was further found that the bolaform Schiff bases film could trap NH3 gas during the acidichromic process.展开更多
The complex formation of 2-hexadecylcarbamoyl-8-hydroxyquinoline(HHQ) monolayers at the air/water interface by reaction with metal ions from the subphase was investigated using X-ray photoelectron spectroscopy. The fo...The complex formation of 2-hexadecylcarbamoyl-8-hydroxyquinoline(HHQ) monolayers at the air/water interface by reaction with metal ions from the subphase was investigated using X-ray photoelectron spectroscopy. The formation of HHQ-metal complexes leads to the appearance of new peaks assigned to the metal ions. The information on stoichimoetry provided by xps indicated that a metal ion is coordinated by two HHQ molecules for La3+ and Cd2+ ions, but by one HHQ molecule for Mn2+ and Ni2+ ions.展开更多
基金Supported by the National Natural Science Foundation of China(No.20806025)
文摘Four ＂picket fence＂ porphyrin atropisomers were respectively synthesized from the four corresponding atropisomers of meso-tetra（o-aminophenyl）porphyrin that had been chromatographed on a column eluted with petroleum ether and ethyl acetate. Results show that each atropisomer could be successfully synthesized by controlling the acylation temperature at 0 ℃. They were characterized by 1H NMR, HRMS, IR, UV-Vis and Langmuir-Blodgett（LB） film analyses. Although the results of HRMS, IR, UV-Vis analyses indicate there is no remarkable difference among the atropisomers, the results of the 1H NMR and the mean molecular areas obtained by LB film technique imply that the atropisomers are significantly discrepant. The former shows that the chemical shifts of the methyl and amide protons of each atropisomer are distinct, while the later presents that the different atropisomer molecules can occupy the different surface areas at the air/water interface.
文摘Mixed Stearic acid and poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS) Langmuir- Blodgett(LB) films were successfully fabricated by the conventional vertical dipping method.Stearic acid and PEDOT/PSS was dissolved in chloroform and spread on subphase containing 0.04wt% FeCl_3.Conductive Y-type mixed LB films was successfully prepared under the condition of surface pressure with 30 mN/m,pH 3.8,and 19℃.UV-VIS spectrum showed that well ordered layer-by-layer fabrication of mixed films were obtained and thickness of single layer film with about 5 nm was evaluated.The morphology image of mixed LB film was observed by atomic force microscopy (AFM).The conductivity of mixed LB film was about 1.8×10^(-5)S/cm and the film showed sensitivity to NH_3 at the same time.
基金Funded by the National Natural Science Foundation of China (No.60372002)
文摘An arachidic acid/poly （3, 4-ethylene dioxythiophene） （AA/PEDOT） multilayer Langmuir-Blodgett （LB） film was prepared by a modified LB film method. The theories were utilized to explain the effects between HCl molecule and LB film. The gas sensitivity mechanism of poly （3, 4-ethylene dioxythiophene） （PEDOT） multilayer film can be explained by the charge transfer between p system of PEDOT and oxidization HCl system. The gas sensitivity of PEDOT LB film deposited interdigital electrode to HCl was tested. The results showed that film thickness, treating temperature, deposition speed had different influence on film gas sensitivity. The AA/PEDOT film deposited device exhibited nonlinear behavior to HCl gas at lower concentration （20-60 ppm） and linear response behavior at higher gas concentration was observed. The time of the compound LB film of the AA/PEDOT responding to the 30 ppm HCl gas is about 20 seconds, which is far quicker than the time of the film to the PEDOTPRESS film（about 80 seconds）. It is not higher film press to better film. When the film press attains 45 mNs/m, the sensitivity of the AA/PEDOT film on the contrary descends.
文摘The surface morphologies of polyimide LB film and the SiC film pyrolyzed from polyimide LB film were studied with STM technique. The results show that molecular chains of polyimide LB film are highly oriented in certain scale, the SiC film keeps the similar regular structure to that of polyimide LB film, suggesting that the SiC formation reaction proceeds on the basis of the lattice of polyimide molecules.
基金This work was supported by the National Natural Science Foundation of China(Nos.20533050 and 90306002)the Fund of the Chinese Academy of Sciences
文摘A bolaform （BNC10） and single-headed （HNOA） amphiphilic Schiff bases containing naphthyl group were designed and their Langmuir-Blodgett films were investigated. It was found that both the LB films show acidichromism, i.e. a reversible color change upon alternatively exposing the films to HC1 and NH3 gases, respectively. It was further found that the bolaform Schiff bases film could trap NH3 gas during the acidichromic process.
文摘The complex formation of 2-hexadecylcarbamoyl-8-hydroxyquinoline(HHQ) monolayers at the air/water interface by reaction with metal ions from the subphase was investigated using X-ray photoelectron spectroscopy. The formation of HHQ-metal complexes leads to the appearance of new peaks assigned to the metal ions. The information on stoichimoetry provided by xps indicated that a metal ion is coordinated by two HHQ molecules for La3+ and Cd2+ ions, but by one HHQ molecule for Mn2+ and Ni2+ ions.
