Polythiophene （PTP） was prepared by a chemical oxidative polymerization and nanosized WO3 was prepared by a colloidal chemical method. The organic-inorganic PTP/WO3 hybrids with different mass fractions of PTP were ...Polythiophene （PTP） was prepared by a chemical oxidative polymerization and nanosized WO3 was prepared by a colloidal chemical method. The organic-inorganic PTP/WO3 hybrids with different mass fractions of PTP were obtained by a simple mechanically mixing the prepared PTP and WO3. The as-prepared PTP/WO3 hybrids have a higher thermal stability than the pure PTP. The gas sensing measurements demonstrate that the PTP/WO3 hybrid sensors exhibit higher response for detecting NO2 at low temperature than the pure PTP and WO3 sensor. The sensing mechanism is suggested to be related to the existence of p-n heterojunctions in the PTP/WO3 hybrids. The response of the PTP/WO3 hybrids is markedly influenced by the PTP mass fraction. The 20% PTP/WO3 hybrid shows high response and good selectivity to NO2 at low temperature （〈90℃）. Therefore, the PTP/WO3 hybrids can be expected to be potentially used as gas sensor material for detecting NO2 at low temperature.展开更多
Polythiophene (PTh) was prepared by the direct electrochemical synthesis in an ionic liquid ([BMIM]PF6) containing 0.1 mol/L thiophene by cyclic voltammetry, constant potential and constant current techniques. It is ...Polythiophene (PTh) was prepared by the direct electrochemical synthesis in an ionic liquid ([BMIM]PF6) containing 0.1 mol/L thiophene by cyclic voltammetry, constant potential and constant current techniques. It is found that smooth and bluegreen PTh films can be obtained at a potential of ca. +1.75 V ( vs. Ag/AgCl ) or a current of ca. 1.5 mA cm-2 in the ionic liquid.展开更多
The deformation measurement of electrosynthesized polythiophene(Pth) thin films is difficult because of the small thickness and highflexibility of the specimen. An electronic speckle patterninterferom- etry (ESPI) met...The deformation measurement of electrosynthesized polythiophene(Pth) thin films is difficult because of the small thickness and highflexibility of the specimen. An electronic speckle patterninterferom- etry (ESPI) method is used to measure the deformation ofPth films of thicknesses in the range of 4-65 μm . Theirstress-strain curves are obtained. It is found that the mechanicalproperties of Pth films are sensitive to the specimen thickness. Thetensile strength increases with decreasing thickness of thin filmfrom 10 μm. The influence of the electrochemical synthesisconditions on the mechanical properties of Pth films is also dis-Cussed.展开更多
Polythiophene/WO3（PTP/WO3）organic-inorganic hybrids were synthesized by an in situ chemical oxidative polymerization method,and char- acterized by X-ray diffraction（XRD）,transmission electron microscopy（TEM）and ...Polythiophene/WO3（PTP/WO3）organic-inorganic hybrids were synthesized by an in situ chemical oxidative polymerization method,and char- acterized by X-ray diffraction（XRD）,transmission electron microscopy（TEM）and thermo-gravimetric analysis（TGA）.The Polythiophene/ WO3 hybrids have higher thermal stability than pure polythiophene,which is beneficial to potential application as chemical sensors.Gas sensing measurements demonstrate that the gas sensor based on the Polythiophene/WO3 hybrids has high response and good selectivity for de- tecting NO2 of ppm level at low temperature.Both the operating temperature and PTP contents have an influence on the response of PTP/WO3 hybrids to NO2.The 10 wt%PTP/WO3 hybrid showed the highest response at low operating temperature of 70-C.It is expected that the PTP/WO3 hybrids can be potentially used as gas sensor material for detecting the low concentration of NO2 at low temperature.展开更多
The Complexation of thiophene with a Lewis acid with moderate acidity as a solvent, such as BF3-ethyl ether (BFEE) remarkedly lowered the electrochemical polymerization potential. The positively charged metal surface ...The Complexation of thiophene with a Lewis acid with moderate acidity as a solvent, such as BF3-ethyl ether (BFEE) remarkedly lowered the electrochemical polymerization potential. The positively charged metal surface of electrode in the process of electrochemical deposition enhanced the coordination interaction between pi-electrons of thiophene unit and the metal, which makes thiophene rings lie parallel to the surface of electrode, resulting in a highly ordered polymeric structure. Because of the large intra-chain transfer integrals, the transport of charge is believed to be principally along the conjugated chains, which is much greater than the inter-chain hopping. The specific electrical resistance across the polythiophene film thickness is more than 10(4) times than that along the surface plane of the film. In this paper we review the recent development of polymerization technique by low potential electrochemical method performed in our lab and several electrical devices in which the compact polythiophene films, such as anionic and cationic sieves, and laminate film junction of undoped polythiophene derivatives were used.展开更多
A polythiophene film was electrochemically deposited on a Pt micro plate electrode and investigated by cyclic voltammetry and in situ reflection microscopic FTIR spectroscopy. The FTIR analysis showed that the e...A polythiophene film was electrochemically deposited on a Pt micro plate electrode and investigated by cyclic voltammetry and in situ reflection microscopic FTIR spectroscopy. The FTIR analysis showed that the electropolymerization of thiophene on the Pt surface was affected by the surface adsorption processes of thiophene molecules. Two adsorption modes were identified. Two structure models of the polythiophene chain were observed simultaneously. It was proposed that the good conductibility of the polythiophene film was originated from a co vibratory equilibrium of the link part of model Ⅰ and model Ⅱ.展开更多
Electrochemical polymerization of 3-fluoroalkoxy and 3-fluoroether thiophenes gives polymers with relatively high molecular weights and good processibility. Investigation of these polymers by means of GPC indicates th...Electrochemical polymerization of 3-fluoroalkoxy and 3-fluoroether thiophenes gives polymers with relatively high molecular weights and good processibility. Investigation of these polymers by means of GPC indicates that an increase in the number of fluorine atoms in the fluorinated group results in a decrease in degree of polymerization of the polymers in the same polythiophene series. As shown by NMR and FTIR, the polyfluorinated group substituted polythiophenes have regular 2, 5-coupling in their main chains. The SEM micrographs of the polymer films exhibit that polymer (1)-poly [3-2, 2, 3, 3-tetrafluoro-propoxy) thiophene] possesses more regular structure than the other polymers do. Substitution of polythiophenes by fluorinated groups leads to the polymers with high electric, electrochemical and thermal stability.展开更多
4,4＇-dibromo-2-nitro-biphenyl and 4,4＇-dibromo-2,3＇-dinitro-biphenyl have been synthesized via nitration reaction with 4,4＇-dibromobiphenyl as the raw material. Three novel thiophene derivatives, 4, 4＇-di（4-hexy...4,4＇-dibromo-2-nitro-biphenyl and 4,4＇-dibromo-2,3＇-dinitro-biphenyl have been synthesized via nitration reaction with 4,4＇-dibromobiphenyl as the raw material. Three novel thiophene derivatives, 4, 4＇-di（4-hexyl-thiophen-2-yl）biphenyl, 4,4＇-di（4-hexyl-thiophen-2-yl）-2- nitro-biphenyl and 4,4＇-di（4- hexyl-thiophen-2-yl）-2,3＇-dinitrobiphenyl were synthesized through Stille coupling reaction, followed by polymerization in the presence of FeC13, respectively. UV-vis absorption spectra, fluorescence spectra, photoluminescence spectra and electrochemical properties of the polymers were investigated. And the band-gap （Eg）, HOMO orbital energy （EHCMO）, and LUMO orbital energy （EUJMO） of the polymers were calculated. Among the polymers, polymer PBTN and PBTD show lower band-gap （2.67 and 2.63 eV）, lower HOMO energy level （-5.38 and -5.4 eV） and broader wavelength （432 and 438 nm） than that of polymer PBTB （2.69 eV, -5.36 eV and 424 nm） with incorporation of one nitro group or two nitro groups in the main chain, respectively.展开更多
The charge and spin-dependent thermoelectric properties of different lengths of polythiophene in a molecular junction are investigated using the B ¨uttiker probe method within Green function formalism in linear r...The charge and spin-dependent thermoelectric properties of different lengths of polythiophene in a molecular junction are investigated using the B ¨uttiker probe method within Green function formalism in linear response regime. The coupling of the molecular chain to three-dimensional ferromagnetic electrodes is described by a tight-binding model for both parallel and antiparallel spin configurations. The decrease of height of transmission probability peaks and thermoelectric coefficients are observed in the presence of the B ¨uttiker probes. The reduction is more intensive in the strong dephased chains.Results show that the spin magnetothermopower is bigger than the charge magnetothermopower due to the larger difference between the spin thermopowers with respect to the charge ones. In addition, we observed that the kind of carriers participating in the thermoelectric transport depends on the number of the thiophene rings.展开更多
We present a first-principles calculation on the electronic and optical properties of a hybrid nanotube system consisting of a （13, 0） single-walled carbon nanotube encapsulated by polythiophene. This hybrid-system ...We present a first-principles calculation on the electronic and optical properties of a hybrid nanotube system consisting of a （13, 0） single-walled carbon nanotube encapsulated by polythiophene. This hybrid-system represents a complete new type of matter and is known as the peapod system. We analyze bow the polythiophene changes the electronic and optical properties of the nanotube. In particular, we examine new features in the dielectric function due to the transitions between the states of the polymer and the nanotube. The electronic structure of the combined system appears to be a simple superposition of the individual constituents. The density functional theory calculations demonstrate van der Waals interaction as the bonding mechanism between the tube and the encapsulated molecule.展开更多
Three series of polythiophenes containing fluoroalkoxy and fluoroether substituents were prepared by electrochemical polymerization. The effect of substituents with fluoroalkoxy or ether functional groups on the elect...Three series of polythiophenes containing fluoroalkoxy and fluoroether substituents were prepared by electrochemical polymerization. The effect of substituents with fluoroalkoxy or ether functional groups on the electrochemical polymerization of thiophene monomers and properties of the obtained polymers were analyzed. The introduction of a fluoroether functional group at the 3-position of the thiophene ring leads to an increase of the oxidation potential of the monomer and to a decrease of the conductivity of the resulting polymers, even with the use of a CH2 group as spacer. Conversely, the presence of an oxygen atom directly at the 3-position of the thiophene ring, which offsets the negative withdrawing effect of fluoroalkyl groups, facilitates the synthesis of highly conducting polythiophenes.展开更多
Polythiophene and its derivatives are getting more andmore attention as a new kind of conducting polymers.Their conductivity,application,possible processingmethods and development are discussed in this article.
The dynamical process of charge injection from metal electrode to a nondegenerate polymer in a metal/polythiophene （PT）/metal structure has been investigated by using a nonadiabatic dynamic approach. It is found tha...The dynamical process of charge injection from metal electrode to a nondegenerate polymer in a metal/polythiophene （PT）/metal structure has been investigated by using a nonadiabatic dynamic approach. It is found that the injected charges form wave packets due to the strong electron-lattice interaction in PT. We demonstrate that the dynamical formation of the wave packet sensitively depends on the strength of applied voltage, the electric field, and the contact between PT and electrode. At a strength of the electric field more than 3.0 × 10^4 V/cm, the carriers can be ejected from the PT into the right electrode. At an electric field more than 3.0 × 10^5 V/cm, the wave packet cannot form while it moves rapidly to the right PT/metal interface. It is shown that the ejected quantity of charge is noninteger.展开更多
基金Foundation item: Project (21171099) supported by the National Natural Science Foundation of ChinaProjects (09JCYBJC03600,10JCYBJC03900) supported by Technology Commission Foundation of Tianjin,China
文摘Polythiophene （PTP） was prepared by a chemical oxidative polymerization and nanosized WO3 was prepared by a colloidal chemical method. The organic-inorganic PTP/WO3 hybrids with different mass fractions of PTP were obtained by a simple mechanically mixing the prepared PTP and WO3. The as-prepared PTP/WO3 hybrids have a higher thermal stability than the pure PTP. The gas sensing measurements demonstrate that the PTP/WO3 hybrid sensors exhibit higher response for detecting NO2 at low temperature than the pure PTP and WO3 sensor. The sensing mechanism is suggested to be related to the existence of p-n heterojunctions in the PTP/WO3 hybrids. The response of the PTP/WO3 hybrids is markedly influenced by the PTP mass fraction. The 20% PTP/WO3 hybrid shows high response and good selectivity to NO2 at low temperature （〈90℃）. Therefore, the PTP/WO3 hybrids can be expected to be potentially used as gas sensor material for detecting NO2 at low temperature.
基金support from the National Natural Science Foundation of China(20004010)
文摘Polythiophene (PTh) was prepared by the direct electrochemical synthesis in an ionic liquid ([BMIM]PF6) containing 0.1 mol/L thiophene by cyclic voltammetry, constant potential and constant current techniques. It is found that smooth and bluegreen PTh films can be obtained at a potential of ca. +1.75 V ( vs. Ag/AgCl ) or a current of ca. 1.5 mA cm-2 in the ionic liquid.
基金the Basic-Research Foundation of Tsinghua University(JC2000057)the Visiting Scholar Foundation of Solid Mechanical Key Lab in Tongji University of the Ministry of Education of China
文摘The deformation measurement of electrosynthesized polythiophene(Pth) thin films is difficult because of the small thickness and highflexibility of the specimen. An electronic speckle patterninterferom- etry (ESPI) method is used to measure the deformation ofPth films of thicknesses in the range of 4-65 μm . Theirstress-strain curves are obtained. It is found that the mechanicalproperties of Pth films are sensitive to the specimen thickness. Thetensile strength increases with decreasing thickness of thin filmfrom 10 μm. The influence of the electrochemical synthesisconditions on the mechanical properties of Pth films is also dis-Cussed.
基金financially supported by the National Natural Science Foundation of China(No.20871071)the Science and Technology Commission Foundation of Tianjin(No.09JCYBJC03600 and 10JCYBJC03900)
文摘Polythiophene/WO3（PTP/WO3）organic-inorganic hybrids were synthesized by an in situ chemical oxidative polymerization method,and char- acterized by X-ray diffraction（XRD）,transmission electron microscopy（TEM）and thermo-gravimetric analysis（TGA）.The Polythiophene/ WO3 hybrids have higher thermal stability than pure polythiophene,which is beneficial to potential application as chemical sensors.Gas sensing measurements demonstrate that the gas sensor based on the Polythiophene/WO3 hybrids has high response and good selectivity for de- tecting NO2 of ppm level at low temperature.Both the operating temperature and PTP contents have an influence on the response of PTP/WO3 hybrids to NO2.The 10 wt%PTP/WO3 hybrid showed the highest response at low operating temperature of 70-C.It is expected that the PTP/WO3 hybrids can be potentially used as gas sensor material for detecting the low concentration of NO2 at low temperature.
文摘The Complexation of thiophene with a Lewis acid with moderate acidity as a solvent, such as BF3-ethyl ether (BFEE) remarkedly lowered the electrochemical polymerization potential. The positively charged metal surface of electrode in the process of electrochemical deposition enhanced the coordination interaction between pi-electrons of thiophene unit and the metal, which makes thiophene rings lie parallel to the surface of electrode, resulting in a highly ordered polymeric structure. Because of the large intra-chain transfer integrals, the transport of charge is believed to be principally along the conjugated chains, which is much greater than the inter-chain hopping. The specific electrical resistance across the polythiophene film thickness is more than 10(4) times than that along the surface plane of the film. In this paper we review the recent development of polymerization technique by low potential electrochemical method performed in our lab and several electrical devices in which the compact polythiophene films, such as anionic and cationic sieves, and laminate film junction of undoped polythiophene derivatives were used.
文摘A polythiophene film was electrochemically deposited on a Pt micro plate electrode and investigated by cyclic voltammetry and in situ reflection microscopic FTIR spectroscopy. The FTIR analysis showed that the electropolymerization of thiophene on the Pt surface was affected by the surface adsorption processes of thiophene molecules. Two adsorption modes were identified. Two structure models of the polythiophene chain were observed simultaneously. It was proposed that the good conductibility of the polythiophene film was originated from a co vibratory equilibrium of the link part of model Ⅰ and model Ⅱ.
基金This work was supported by the National Natural Science Foundation of China.
文摘Electrochemical polymerization of 3-fluoroalkoxy and 3-fluoroether thiophenes gives polymers with relatively high molecular weights and good processibility. Investigation of these polymers by means of GPC indicates that an increase in the number of fluorine atoms in the fluorinated group results in a decrease in degree of polymerization of the polymers in the same polythiophene series. As shown by NMR and FTIR, the polyfluorinated group substituted polythiophenes have regular 2, 5-coupling in their main chains. The SEM micrographs of the polymer films exhibit that polymer (1)-poly [3-2, 2, 3, 3-tetrafluoro-propoxy) thiophene] possesses more regular structure than the other polymers do. Substitution of polythiophenes by fluorinated groups leads to the polymers with high electric, electrochemical and thermal stability.
基金Supported by the National Natural Science Foundation of China(No.21176193)
文摘4,4＇-dibromo-2-nitro-biphenyl and 4,4＇-dibromo-2,3＇-dinitro-biphenyl have been synthesized via nitration reaction with 4,4＇-dibromobiphenyl as the raw material. Three novel thiophene derivatives, 4, 4＇-di（4-hexyl-thiophen-2-yl）biphenyl, 4,4＇-di（4-hexyl-thiophen-2-yl）-2- nitro-biphenyl and 4,4＇-di（4- hexyl-thiophen-2-yl）-2,3＇-dinitrobiphenyl were synthesized through Stille coupling reaction, followed by polymerization in the presence of FeC13, respectively. UV-vis absorption spectra, fluorescence spectra, photoluminescence spectra and electrochemical properties of the polymers were investigated. And the band-gap （Eg）, HOMO orbital energy （EHCMO）, and LUMO orbital energy （EUJMO） of the polymers were calculated. Among the polymers, polymer PBTN and PBTD show lower band-gap （2.67 and 2.63 eV）, lower HOMO energy level （-5.38 and -5.4 eV） and broader wavelength （432 and 438 nm） than that of polymer PBTB （2.69 eV, -5.36 eV and 424 nm） with incorporation of one nitro group or two nitro groups in the main chain, respectively.
文摘The charge and spin-dependent thermoelectric properties of different lengths of polythiophene in a molecular junction are investigated using the B ¨uttiker probe method within Green function formalism in linear response regime. The coupling of the molecular chain to three-dimensional ferromagnetic electrodes is described by a tight-binding model for both parallel and antiparallel spin configurations. The decrease of height of transmission probability peaks and thermoelectric coefficients are observed in the presence of the B ¨uttiker probes. The reduction is more intensive in the strong dephased chains.Results show that the spin magnetothermopower is bigger than the charge magnetothermopower due to the larger difference between the spin thermopowers with respect to the charge ones. In addition, we observed that the kind of carriers participating in the thermoelectric transport depends on the number of the thiophene rings.
文摘We present a first-principles calculation on the electronic and optical properties of a hybrid nanotube system consisting of a （13, 0） single-walled carbon nanotube encapsulated by polythiophene. This hybrid-system represents a complete new type of matter and is known as the peapod system. We analyze bow the polythiophene changes the electronic and optical properties of the nanotube. In particular, we examine new features in the dielectric function due to the transitions between the states of the polymer and the nanotube. The electronic structure of the combined system appears to be a simple superposition of the individual constituents. The density functional theory calculations demonstrate van der Waals interaction as the bonding mechanism between the tube and the encapsulated molecule.
基金This work was supported by the National Natural Science Foundation of China.
文摘Three series of polythiophenes containing fluoroalkoxy and fluoroether substituents were prepared by electrochemical polymerization. The effect of substituents with fluoroalkoxy or ether functional groups on the electrochemical polymerization of thiophene monomers and properties of the obtained polymers were analyzed. The introduction of a fluoroether functional group at the 3-position of the thiophene ring leads to an increase of the oxidation potential of the monomer and to a decrease of the conductivity of the resulting polymers, even with the use of a CH2 group as spacer. Conversely, the presence of an oxygen atom directly at the 3-position of the thiophene ring, which offsets the negative withdrawing effect of fluoroalkyl groups, facilitates the synthesis of highly conducting polythiophenes.
文摘Polythiophene and its derivatives are getting more andmore attention as a new kind of conducting polymers.Their conductivity,application,possible processingmethods and development are discussed in this article.
基金Project supported by the State Key Program of National Natural Science of China (Grant Nos 10474056 and 10574082)the Natural Science Foundation of Shandong Province (Grant No Z2005A01)
文摘The dynamical process of charge injection from metal electrode to a nondegenerate polymer in a metal/polythiophene （PT）/metal structure has been investigated by using a nonadiabatic dynamic approach. It is found that the injected charges form wave packets due to the strong electron-lattice interaction in PT. We demonstrate that the dynamical formation of the wave packet sensitively depends on the strength of applied voltage, the electric field, and the contact between PT and electrode. At a strength of the electric field more than 3.0 × 10^4 V/cm, the carriers can be ejected from the PT into the right electrode. At an electric field more than 3.0 × 10^5 V/cm, the wave packet cannot form while it moves rapidly to the right PT/metal interface. It is shown that the ejected quantity of charge is noninteger.
