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 colorimetric and fluorometric dual probe based on a water-soluble polythiophene derivative(PMTPBA)was designed and synthesized.It can be applied to determination of picric acid(PA) in 100% aqueous solution.The appro...A colorimetric and fluorometric dual probe based on a water-soluble polythiophene derivative(PMTPBA)was designed and synthesized.It can be applied to determination of picric acid(PA) in 100% aqueous solution.The approach relies on the formation of supramolecular polythiophene assemblies in the presence of PA through electrostatic,charge transfer and π-π stacking interactions.This probe could be utilized for the rapid and visual detection of PA both in aqueous solution and solid support with high specificity and sensitivity.The detection limit of this sensor is as low as 5.0 × 10^-8 mol/L.展开更多
Electrical and magnetic properties are two crucial factors for the designing of broadband electromagnetic wave absorption(EWA)materials.In this work,we synthesized various magnetic metal sulfides/carbon(M_(x)S_(y)/C)n...Electrical and magnetic properties are two crucial factors for the designing of broadband electromagnetic wave absorption(EWA)materials.In this work,we synthesized various magnetic metal sulfides/carbon(M_(x)S_(y)/C)nanocomposites from the precursor complex of metal in microporous polythiophene(MPT),and systematically investigated their EWA properties and mechanism.The characterization results indicate that M_(x)S_(y) were determined to be Fe_(7)S_(8)/C,Co_(9)S_(8)/C and Ni_(4)S_(3)/C,respectively.It is observed that M_(x)S_(y)/C nanocomposites exhibit remarkable EWA performances,where the maximal absorption gets to-51.3 dB,and efficient absorption can be realized in 10.32-18 GHz(7.68 GHz),which is superior to most reported magnetic carbonaceous EWA composites.Beside,the efficient absorption can be tuned to cover Ku band X band,demonstrating their great potential in practical applications.Improved conductance loss,obvious polarization relaxation,and apparent eddy current loss are deemed to make the predominant contributions to the high-performance EWA.This research opens up the exploration of novel nanocomposite coupling dielectric loss and magnetic loss using MPT-metal complex precursor for EWA applications.展开更多
In this study, we demonstrate a novel method for fabricating polythiophene patterns, i.e., cylindrical holes and cylinders, through blending of a thermally curable polythiophene carrying with tertiary ester groups(PT-...In this study, we demonstrate a novel method for fabricating polythiophene patterns, i.e., cylindrical holes and cylinders, through blending of a thermally curable polythiophene carrying with tertiary ester groups(PT-tert-ESTER) and poly(methyl methacrylate)(PMMA), followed by thermal conversion of the PT-tert-ESTER to an insoluble polythiophene via low-temperature cleavage of the tertiary ester groups and removal of the PMMA component via ultraviolet degradation. We show that the surface polarity of substrates, the mass ratio of PT-tert-ESTER to PMMA in the blend solutions as well as the concentration of the blend solutions strongly influence the formation of the polythiophene patterns. Cylindrical holes are more readily formed on less polar substrates when a PT-tert-ESTER dominated blend solution is used, while cylinders are more readily formed on more polar substrates when a PMMA dominated blend solution is used. Moreover, the diameters of both the cylindrical holes and the cylinders decrease as the PT-tert-ESTER concentration is increased in the respective ranges of the PT-tert-ESTER/PMMA ratios where the patterns are formed. Grazing incident X-ray diffraction data have indicated that the patterning of the PT-tert-ESTER component in the blend films improves the crystallinity of PT-tert-ESTER as well as the molecular packing of the insoluble polythiophene in the resultant patterned polythiophene films.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
The power conversion efficiencies(PCEs)of organic solar cells(OSCs)have reached 18%recently,which have already met the demand of practical application.However,these outstanding results were generally achieved with don...The power conversion efficiencies(PCEs)of organic solar cells(OSCs)have reached 18%recently,which have already met the demand of practical application.However,these outstanding results were generally achieved with donor-acceptor(D-A)type copolymer donors,which can hardly fulfill the low-cost largescale production due to their complicated synthesis processes.Therefore,developing polymer donors with simple chemical structures is urgent for realizing low-cost OSCs.Polythiophene(PT)derivatives are currently regarded as promising candidates for such kind of donor materials,which has been illustrated in many works.In this work,two new alkylthio substituted PT derivatives,P301 and P302,were synthesized and tested as donors in the OSCs using Y5 as the accepto r.In comparison,the introduction of fluorine atoms on the backbone of P302 can not only downshift the energy levels,but also greatly improve the phase separation morphologies of the active layers,which is ascribed to the enhanced aggregation effect and the reduced miscibility with the non-fullerene acceptor.As a result,the P302:Y5-based OSC exhibits a significantly improved PCE of 9.65%than that of P301:Y5-based one,indicating the important role of fluorination in the construction of efficient PT derivative donors.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
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
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
A water-soluble, polythiophene-based colorimetric sensor was designed for selective and sensitive detection of carbenicillin in HEPES buffer solution. Quaternized quinine was linked to thiophene through bis-functional...A water-soluble, polythiophene-based colorimetric sensor was designed for selective and sensitive detection of carbenicillin in HEPES buffer solution. Quaternized quinine was linked to thiophene through bis-functionality benzyl group, which can interact with carbenicillin via electrostatic interaction and geometric match effect. The sensor exhibited a colorimetric signal change upon the addition of carbenicillin because of the formation of more nonplanar structures. However, the addition of other beta-lactarn antibiotics or dicarboxylic acids into the sensor solution caused no obvious changes in absorbance intensity ratio. This result may be attributed to the cavity formed by the semi-rigid framework of PTQ2, which is suitable for the special binding with carbenicillin. This novel sensor can effectively distinguish carbenicillin from other beta-lactam antibiotics and has a wide linear range response in HEPES buffer solution. Linear calibration curves are obtained with 0 to 18 μmol/L of HEPES buffer solution, with a limit of detection of 0.54μmol/L.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
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
Electrorheological properties and creep-recovery behavior of polythiophene/polyoxymethylene-blend having PT（50%）/POM（50%） composition were investigated.Particle size,conductivity and dielectric values were measure...Electrorheological properties and creep-recovery behavior of polythiophene/polyoxymethylene-blend having PT（50%）/POM（50%） composition were investigated.Particle size,conductivity and dielectric values were measured to be 24.77μm,3.85×10^（-5） S·m^（-1） and 26.75,respectively.Sedimentation ratio was measured to be 64%at the end of 16 days.The effects of dispersed particle volume fraction,external electric field strength,shear rate,frequency and temperature on ER properties and storage modulus of PT/POM-blend/silicone oil（SO） suspensions were examined.Enhancement were observed in the electric field viscosities of the suspensions and thus they were classified as a smart material.Shear thinning non-Newtonian viscoelastic behavior was determined for PT/POM-blend/SO system.Further,time-dependent deformation was examined by creep-recovery tests and recoverable viscoelastic deformation established.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.
In polymers, the electronic activation energy depends on the fragmentation, crosslinking, dopants, moisture and in general on the structure-environment interaction. This has a special importance in plasma polymers bec...In polymers, the electronic activation energy depends on the fragmentation, crosslinking, dopants, moisture and in general on the structure-environment interaction. This has a special importance in plasma polymers because fragmentation and crosslinking are usually higher than in other polymers. In this work, DC electrical conductivity of polythiophene thin films prepared by plasma (pPTh) was studied using the Meyer-Neldel (MN) rule to calculate the characteristic MN energy and temperature as a function of moisture and metallic dopants. The experimental data for pPTh synthesized in different conditions indicated that EM = 32 meV and TM = 373 K, suggesting a thermally activated conduction mechanism;however, in polymer-metal matrices with metal concentration higher than the percolation threshold, the conduction mechanism is different causing that the MN rule was only partially fulfilled. The congruence of the experimental data with the multiexcitation entropy model is discussed.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.
基金financially supported by the National Natural Science Foundation of China(No.31871877)Chinese Universities Scientific Fund(Nos.2018QC151,2019TC036)+1 种基金the"Talents Scheme"Program of Beijing(No.31050003)the Research Fund Program of Guangdong Provincial Key Laboratory of Radionuclides Pollution Control and Resources(No.2017B030314182)。
文摘A colorimetric and fluorometric dual probe based on a water-soluble polythiophene derivative(PMTPBA)was designed and synthesized.It can be applied to determination of picric acid(PA) in 100% aqueous solution.The approach relies on the formation of supramolecular polythiophene assemblies in the presence of PA through electrostatic,charge transfer and π-π stacking interactions.This probe could be utilized for the rapid and visual detection of PA both in aqueous solution and solid support with high specificity and sensitivity.The detection limit of this sensor is as low as 5.0 × 10^-8 mol/L.
基金financially supported by the Fundamental Research Funds for the Central Universities(No.30920021107)the National Natural Science Foundation of China(No.51702161)。
文摘Electrical and magnetic properties are two crucial factors for the designing of broadband electromagnetic wave absorption(EWA)materials.In this work,we synthesized various magnetic metal sulfides/carbon(M_(x)S_(y)/C)nanocomposites from the precursor complex of metal in microporous polythiophene(MPT),and systematically investigated their EWA properties and mechanism.The characterization results indicate that M_(x)S_(y) were determined to be Fe_(7)S_(8)/C,Co_(9)S_(8)/C and Ni_(4)S_(3)/C,respectively.It is observed that M_(x)S_(y)/C nanocomposites exhibit remarkable EWA performances,where the maximal absorption gets to-51.3 dB,and efficient absorption can be realized in 10.32-18 GHz(7.68 GHz),which is superior to most reported magnetic carbonaceous EWA composites.Beside,the efficient absorption can be tuned to cover Ku band X band,demonstrating their great potential in practical applications.Improved conductance loss,obvious polarization relaxation,and apparent eddy current loss are deemed to make the predominant contributions to the high-performance EWA.This research opens up the exploration of novel nanocomposite coupling dielectric loss and magnetic loss using MPT-metal complex precursor for EWA applications.
基金financially supported by the National Natural Science Foundation of China(Nos.21274158 and 91333114)the National Research Laboratory Program of the Korea Science and Engineering Foundation(KOSEF)+1 种基金the World Class University Program(No.R32-2008-000-10142-0)the Center for Nanoscale Mechatronics&Manufacturing(08K140100414,CNMM)
文摘In this study, we demonstrate a novel method for fabricating polythiophene patterns, i.e., cylindrical holes and cylinders, through blending of a thermally curable polythiophene carrying with tertiary ester groups(PT-tert-ESTER) and poly(methyl methacrylate)(PMMA), followed by thermal conversion of the PT-tert-ESTER to an insoluble polythiophene via low-temperature cleavage of the tertiary ester groups and removal of the PMMA component via ultraviolet degradation. We show that the surface polarity of substrates, the mass ratio of PT-tert-ESTER to PMMA in the blend solutions as well as the concentration of the blend solutions strongly influence the formation of the polythiophene patterns. Cylindrical holes are more readily formed on less polar substrates when a PT-tert-ESTER dominated blend solution is used, while cylinders are more readily formed on more polar substrates when a PMMA dominated blend solution is used. Moreover, the diameters of both the cylindrical holes and the cylinders decrease as the PT-tert-ESTER concentration is increased in the respective ranges of the PT-tert-ESTER/PMMA ratios where the patterns are formed. Grazing incident X-ray diffraction data have indicated that the patterning of the PT-tert-ESTER component in the blend films improves the crystallinity of PT-tert-ESTER as well as the molecular packing of the insoluble polythiophene in the resultant patterned polythiophene films.
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.
基金the financial support from the Basic and Applied Basic Research Major Program of Guangdong Province(No.2019B030302007)the National Natural Science Foundation of China(Nos.21835006,91633301 and 22075017)+1 种基金the Fundamental Research Funds for the Central Universities,China(No.FRF-TP-19-047A2)Beijing National Laboratory for Molecular Sciences(No.BNLMS-CXXM-201903)。
文摘The power conversion efficiencies(PCEs)of organic solar cells(OSCs)have reached 18%recently,which have already met the demand of practical application.However,these outstanding results were generally achieved with donor-acceptor(D-A)type copolymer donors,which can hardly fulfill the low-cost largescale production due to their complicated synthesis processes.Therefore,developing polymer donors with simple chemical structures is urgent for realizing low-cost OSCs.Polythiophene(PT)derivatives are currently regarded as promising candidates for such kind of donor materials,which has been illustrated in many works.In this work,two new alkylthio substituted PT derivatives,P301 and P302,were synthesized and tested as donors in the OSCs using Y5 as the accepto r.In comparison,the introduction of fluorine atoms on the backbone of P302 can not only downshift the energy levels,but also greatly improve the phase separation morphologies of the active layers,which is ascribed to the enhanced aggregation effect and the reduced miscibility with the non-fullerene acceptor.As a result,the P302:Y5-based OSC exhibits a significantly improved PCE of 9.65%than that of P301:Y5-based one,indicating the important role of fluorination in the construction of efficient PT derivative donors.
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.
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financially supported by the National Natural Science Foundation of China(Nos.20903110 and 21173244)
文摘A water-soluble, polythiophene-based colorimetric sensor was designed for selective and sensitive detection of carbenicillin in HEPES buffer solution. Quaternized quinine was linked to thiophene through bis-functionality benzyl group, which can interact with carbenicillin via electrostatic interaction and geometric match effect. The sensor exhibited a colorimetric signal change upon the addition of carbenicillin because of the formation of more nonplanar structures. However, the addition of other beta-lactarn antibiotics or dicarboxylic acids into the sensor solution caused no obvious changes in absorbance intensity ratio. This result may be attributed to the cavity formed by the semi-rigid framework of PTQ2, which is suitable for the special binding with carbenicillin. This novel sensor can effectively distinguish carbenicillin from other beta-lactam antibiotics and has a wide linear range response in HEPES buffer solution. Linear calibration curves are obtained with 0 to 18 μmol/L of HEPES buffer solution, with a limit of detection of 0.54μmol/L.
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.
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.
基金financially supported by Turkish Scientific and Technological Research Council(No.107 T 711)
文摘Electrorheological properties and creep-recovery behavior of polythiophene/polyoxymethylene-blend having PT（50%）/POM（50%） composition were investigated.Particle size,conductivity and dielectric values were measured to be 24.77μm,3.85×10^（-5） S·m^（-1） and 26.75,respectively.Sedimentation ratio was measured to be 64%at the end of 16 days.The effects of dispersed particle volume fraction,external electric field strength,shear rate,frequency and temperature on ER properties and storage modulus of PT/POM-blend/silicone oil（SO） suspensions were examined.Enhancement were observed in the electric field viscosities of the suspensions and thus they were classified as a smart material.Shear thinning non-Newtonian viscoelastic behavior was determined for PT/POM-blend/SO system.Further,time-dependent deformation was examined by creep-recovery tests and recoverable viscoelastic deformation established.
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.
文摘In polymers, the electronic activation energy depends on the fragmentation, crosslinking, dopants, moisture and in general on the structure-environment interaction. This has a special importance in plasma polymers because fragmentation and crosslinking are usually higher than in other polymers. In this work, DC electrical conductivity of polythiophene thin films prepared by plasma (pPTh) was studied using the Meyer-Neldel (MN) rule to calculate the characteristic MN energy and temperature as a function of moisture and metallic dopants. The experimental data for pPTh synthesized in different conditions indicated that EM = 32 meV and TM = 373 K, suggesting a thermally activated conduction mechanism;however, in polymer-metal matrices with metal concentration higher than the percolation threshold, the conduction mechanism is different causing that the MN rule was only partially fulfilled. The congruence of the experimental data with the multiexcitation entropy model is discussed.
