Metal-organic frameworks(MOFs)have gained attention in the development of MOFs/polymer hybrid membranes for pervaporation.However,the agglomeration of MOFs particles and interfacial defects limit its further applicati...Metal-organic frameworks(MOFs)have gained attention in the development of MOFs/polymer hybrid membranes for pervaporation.However,the agglomeration of MOFs particles and interfacial defects limit its further application.In this study,we present a novel approach to fabricate a ZIF-8@PEBAX/PVDF nanocomposite membrane for removing thiophene from the model gasoline by combination of selfassembly and in-situ growth.Firstly,a PVDF supporting membrane was modified to have a negative charge.Next,positively charged zinc ions were attracted onto the negatively charged PVDF supporting membrane through electrostatic interaction.Afterwards,the Zinc ions deposited PVDF membrane was immersed into dimethylimidazole solution to form a uniform ZIF-8 layer.Finally,the ZIF-8 layer was coated with poly(ether-block-amide)(PEBAX)using the pouring method.Experimental results showed that the separating efficiency of the ZIF-8@PEBAX/PVDF nanocomposite membrane was improved significantly compared to that of pristine PEBAX membrane.The optimal permeation flux and enrichment factor of membrane were 27.80 kg(m^(2)h)^(-1)and 6.9,respectively.展开更多
Thiophene C4H4S and 3-methylthiophene3-MC4H4S are typical thiophenenic sulfur compounds that exist in fluid catalytic cracking FCC gasoline. Oxidation of C4H4S and 3-MC4H4S were conducted in hydrogen peroxide H2O2 and...Thiophene C4H4S and 3-methylthiophene3-MC4H4S are typical thiophenenic sulfur compounds that exist in fluid catalytic cracking FCC gasoline. Oxidation of C4H4S and 3-MC4H4S were conducted in hydrogen peroxide H2O2 and formic acid system over a series of silica gel loaded with metal oxide. The silica gel loaded with copper and cobalt 1:1 oxide was found very active for the model compound oxidation using H2O2formic acid, while the silica gel unloaded with metal oxide was less active. The sulfur removal rate of thiophenes was dif- ferent as solvent was changed. And the conversation of C4H4S and 3-MC4H4S was improved at higher temperature, but reduced when olefin was added. The sulfur removal rate of model sulfur compounds was enhanced when the phase transfer catalyst emulsifier polyethylene glycol octyl phenyl ether or tetrabutylammonium bromideTBAB was added. The sulfur removal rate of simulated gasoline containing 524μg·ml-1 sulfur reached 90%. Interestingly, in a H2O2 and formic acid system with the addition of TBAB, a bromine substitution trend appeared in the oxidation of thiophenes, suggesting the influence of TBAB.展开更多
Photocatalytic oxidation kinetics of thiophene in n-octane/water extraction system was studied with fluorine and ferric ion codoped nano-TiO<sub>2</sub>(nano-F<sup>-</sup>/Fe<sup>3+</s...Photocatalytic oxidation kinetics of thiophene in n-octane/water extraction system was studied with fluorine and ferric ion codoped nano-TiO<sub>2</sub>(nano-F<sup>-</sup>/Fe<sup>3+</sup>/TiO<sub>2</sub>) powders used as the photocatalyst.Effects of initial concentration of thiophene and additional dosage of F<sup>-</sup>/Fe<sup>3+</sup>/TiO<sub>2</sub> on the reaction rate constant and half-life were investigated.The results showed that the appropriately added dosage of F<sup>-</sup>/Fe<sup>3+</sup>/TiO<sub>2</sub> was 0.1 g in the 100-mL reaction system and the photooxidative kinetics of thiophene in the presence of F<sup>-</sup>/Fe<sup>3+</sup>/TiO<sub>2</sub> catalyst was of first-order with a rate constant of 0.6508 h<sup>-1</sup> and a half-life of 1.0651 h.The desulfurization rate of thiophene was 98.1%in 5 h and the sulfur content could be reduced from 800 ppm to 15 ppm.The reaction rate constant increased with a decreasing initial concentration of thiophene.展开更多
The HY,Hβ,HZSM-5,and SAPO-11 zeolites were investigated in the alkylation reaction of thiophene and olefins.As a result,some sulfur-containing impurities could be converted to higher molecular weight components with ...The HY,Hβ,HZSM-5,and SAPO-11 zeolites were investigated in the alkylation reaction of thiophene and olefins.As a result,some sulfur-containing impurities could be converted to higher molecular weight components with their boiling point being in the range of diesel fraction.HZSM-5 had the highest activity and selectivity of desulfurization.At the same time,extensive oligomerization of olefins was not found and coke yield was very low,which could lead to high yield of gasoline products.The main reaction mechanism verifies that the second order alkylation reaction can be carried out on the outer surface and/or pores of the catalyst.The catalytic performance of the HZSM-5 catalyst which is poisoned by 2,4-dimethylquinoline during alkylation to form larger molecules of sulfur compounds is obviously weakened due to the decrease of the acid sites on the outer surface and at the mouth of pores.展开更多
A novel macrocycle containing thiophene （L） was prepared first by the interaction of 2,5-bis-（chloromethyl）-thiophene （A） and salicylaldehyde to give 2, 5-bis-（2-formylphenoxymethyl）-thiophene （B）, and then ...A novel macrocycle containing thiophene （L） was prepared first by the interaction of 2,5-bis-（chloromethyl）-thiophene （A） and salicylaldehyde to give 2, 5-bis-（2-formylphenoxymethyl）-thiophene （B）, and then by the nontemplate cyclocondensation of 1,3-diaminopropane with （B） followed by a "onepot" reduction without isolation of the diimine intermediate. The corresponding silver complex, AgLClO<sub>4</sub>, was also prepared. The macrocycle was characterized by IR, elemental analysis, MS and <sup>1</sup>HNMR.展开更多
The selection and design of an optimal solvent for extractive distillation require reliable vapour-liquid phase equilibrium data and knowledge of extraction mechanisms.Compared with time-consuming experiments,molecula...The selection and design of an optimal solvent for extractive distillation require reliable vapour-liquid phase equilibrium data and knowledge of extraction mechanisms.Compared with time-consuming experiments,molecular simulation presents great potential in research on the properties of fluids.Therefore,in this work,Gibbs ensemble Monte Carlo was applied to successfully predict the vapour-liquid phase equilibrium data of binary and ternary systems containing benzene,thiophene and N,Ndimethylformamide(DMF) at P=101.3 kPa.The explicit hydrogen version of the transferable potentials for phase equilibria potential model was chosen for benzene and thiophene,whereas the OPLS potential model was selected for DMF.The predicted phase diagrams were compared with experimental data and the UNIQUAC thermodynamic model.A good agreement was obtained,which corroborated the validity of the potential models.In addition,the extraction mechanism was explored by radial distribution function(RDF) of the liquid-phase structure.The RDFs showed that thiophene and benzene shared a similar liquidphase structure because of the intermolecular interaction.The distinct difference between the RDFs of DMF/benzene and those of DMF/thiophene is that the oxygen atom of DMF is more associated with hydrogen atoms of thiophene than that of benzene,which may be responsible for the extraction effect of DMF.展开更多
The second-order nonlinear optical properties of thiophene S,S -dioxides derivatives were studied by using the ZINDO-SOS method. The computed results show that the thiophene S,S -dioxide derivatives exhibit larger sec...The second-order nonlinear optical properties of thiophene S,S -dioxides derivatives were studied by using the ZINDO-SOS method. The computed results show that the thiophene S,S -dioxide derivatives exhibit larger second-order polarizabilities than their thiophene precursors. In order to clarify the origin of the different NLO responses among these chromophores, their electron properties and frontier orbital properties were investigated as well. These thiophene S,S -dioxides derivatives are good candidates for their application in electro-optical device due to their high nonlinearities, good thermal and photo stabilities.展开更多
Competition of hydrocarbon compounds with sulfides in gasoline has caused a not very high selectivity of sulfides in adsorption desulfurization so far,resulting in a reduction of catalyst lifetime as well as more sulf...Competition of hydrocarbon compounds with sulfides in gasoline has caused a not very high selectivity of sulfides in adsorption desulfurization so far,resulting in a reduction of catalyst lifetime as well as more sulfur oxide emissions.Tostudy the whole competitive process changing with the increase of the loading,the dynamic competition adsorption mechanism of cyclohexene and thiophene in siliceous faujasite(FAU)zeolite was analyzed by the Monte Carlo simulation.The results showed that with the increase of the loading,thiophene and cyclohexene had different performances before and after the inflection point of 40 molecule/UC.The adsorbates were distributed ideally at optimal sites during the stage that occurred before the inflection point,which is called the“optimal-displacement adsorption”stage.When approaching the inflection point,the competition became apparent and the displacement appeared accordingly,some thiophene molecules at S sites(refers to the sites inside the supercages)were displaced by cyclohexene.After the inflection point,the concentration of adsorbates at W sites(refers to the 12-membered ring connecting the supercages)was significantly reduced,whereas the adsorbates at S sites got more concentrated.The stage some cyclohexene molecules displaced by thiophene and inserted into the center of the supercage can be named as the“insertion-displacement adsorption”stage,and both the adsorption behavior and the competitive relationship became localized when the adsorption amount became saturated.This shift in the competitive adsorption mechanism was due to the sharp increase of interaction energy between the adsorbates.Besides,the increase in temperature and ratio of Si/Al will allow the adsorbates,especially thiophene molecules to occupy more adsorption sites,and it is beneficial to improve the desulfurization selectivity.展开更多
Lewis acid–base passivation is a significant technique to achieve structural stability of perovskite solar cells(PSCs) by overcoming the issues of wide grain boundaries, crystal defects, and the instability of PSCs. ...Lewis acid–base passivation is a significant technique to achieve structural stability of perovskite solar cells(PSCs) by overcoming the issues of wide grain boundaries, crystal defects, and the instability of PSCs. In this work, the combined effects of thiophene with phthalocyanine(Pc) as isomers(S2 and S3)on the photovoltaic performance of PSCs were studied for the first time. Through density functional theory calculations, we confirmed that the position of the S atom in the structure affects Lewis acid–base interactions with under-coordinated Pb^(2+) sites. The morphology of methylammonium lead iodide(MAPbI_(3)) for passivated devices was improved and thin dense layers with compact surface and large grain size were observed, leading to improvement of the charge extraction ability and reduction of non-radiative recombination and the trap density. A highest power conversion efficiency of 18% was achieved for the Pc S3 passivated device, which was 6.69% more than that of the controlled device.Furthermore, the Pcs passivated devices demonstrated remarkable stability under high-moisture and high-temperature conditions.展开更多
The reaction mechanism of thiophene on vanadium oxides under FCC operating conditions hadbeen preliminary studied using in-situ FT-IR analysis of thiophene and atmospheric pressure continuousfixed-bed reaction, follow...The reaction mechanism of thiophene on vanadium oxides under FCC operating conditions hadbeen preliminary studied using in-situ FT-IR analysis of thiophene and atmospheric pressure continuousfixed-bed reaction, followed by characterization via pyridine adsorption-temperature programmed desorptionmethod, and FT-IR and XPS spectra. The research had discovered that, under 500℃ thiophene could undergothe redox reaction with V2O5, while being converted into CO, CO2 as well as SO2 with its conversion ratereaching 41.2%. At the same time the oxidation number of vanadium decreased. The existence of a few Brnstedacid centers on V2O5 could lead to an increase of H2S yield among the products derived from the reaction withthiophene.展开更多
The mass transfer of thiophene through pervaporation(PV)membranes could be facilitated by certain transitional metal ions like Ag^+,Mn^2+,and Cr^3+thanks to their p complexation with thiophene.In this study,Ag^+,Mn^2+...The mass transfer of thiophene through pervaporation(PV)membranes could be facilitated by certain transitional metal ions like Ag^+,Mn^2+,and Cr^3+thanks to their p complexation with thiophene.In this study,Ag^+,Mn^2+,and Cr^3+ions were loaded onto the polyether block amide(PEBAX)/PAN composite membranes and were tested on the performance for separation of thiophene/n-heptane mixture.Pervaporation test results showed that the pervaporative separation index increased significantly to 73.1%,75.5%,and 97.2%at 30℃for the Ag^+-,Mn2^+-,Cr3^+-loaded PEBAX membranes,respectively,as compared to the pristine PEBAX/PAN composite membrane.展开更多
A new method for the synthesis of substituted thiophenes was through intramolecular aldol condensation ofα-oxo ketene dibenzylthioacetals.All products were confirmed with IR, 1 H NMR and elemental analysis.
A novel monomer, (trans)-7-[4-N,N-(di-β-hydroxyethyl) amino-benzene]-ethenyl-3,5-dinitro-thiophene (HBDT), was synthesized and characterized. The details of synthesizing the monomer andprepolymer, polyurethane with t...A novel monomer, (trans)-7-[4-N,N-(di-β-hydroxyethyl) amino-benzene]-ethenyl-3,5-dinitro-thiophene (HBDT), was synthesized and characterized. The details of synthesizing the monomer andprepolymer, polyurethane with the monomer covalently incorporated are presented. The prepolymer andpolyurethane exhibited good solubility in common organic solvents. Molecular nonlinear optical properties ofthe monomer (HBDT) substituted thiophene based stilbenes is presented.展开更多
A series of conjugated copolymers derived from 9-ethylhexyl-2,7-carbazole(Cz)and 4,7-di(4-hexylthien-2-yl)- 2,1,3-benzothiadiazole(DHTBT)was synthesized by Suzuki polycondensation.The photo-and electro-luminescent pro...A series of conjugated copolymers derived from 9-ethylhexyl-2,7-carbazole(Cz)and 4,7-di(4-hexylthien-2-yl)- 2,1,3-benzothiadiazole(DHTBT)was synthesized by Suzuki polycondensation.The photo-and electro-luminescent properties of these polymers were investigated.Efficient energy transfer from the Cz segment to the DHTBT unit occurs even if the DHTBT content as low as 1 mol%.PL emission was red-shifted significantly from 645 nm to 700 nm with the increase in DHTBT content by 1-50 mol%.PL efficiencies decrea...展开更多
The performance of polymer field-effect transistors is improved by thermal crosslinking of poly(3-hexylthiophene),using ditert butyl peroxide as the crosslinker.The device performance depends on the crosslinker concen...The performance of polymer field-effect transistors is improved by thermal crosslinking of poly(3-hexylthiophene),using ditert butyl peroxide as the crosslinker.The device performance depends on the crosslinker concentration significantly.We obtain an optimal on/off ratio of 105 and the saturate field-effect mobility of 0.34 cm2V−1s−1,by using a suitable ratios of ditert butyl peroxide,0.5 wt%of poly(3-hexylthiophene).The microstructure images show that the crosslinked poly(3-hexylthiophene)active layers simultaneously possess appropriate crystallinity and smooth morphology.Moreover,crosslinking of poly(3-hexylthiophene)prevents the transistors from large threshold voltage shifts under ambient bias-stressing,showing an advantage in encouraging device environmental and operating stability.展开更多
The starting 1-phenylbutane-1,3-dione (1) was used as key intermediate for the synthesis of several new thiophene and pyrazole derivatives. The newly synthesized compounds were evaluated for in vitro cytotoxicity agai...The starting 1-phenylbutane-1,3-dione (1) was used as key intermediate for the synthesis of several new thiophene and pyrazole derivatives. The newly synthesized compounds were evaluated for in vitro cytotoxicity against an Ehrlich ascites cells and in vivo cytotoxicity for compound 10d using EAC assay and 5-fluorouracil is used as reference drug. Compounds 7c, e and 10c, d showed significant activity in certain cancer cell and have been targeted for further studies, compound 10d is more effective and showed the highest activity. Structures of the newly prepared compounds were confirmed by both spectral, analytical data and molecular calculations.展开更多
基金the National Natural Science Foundation of China(22271022)Hubei Three Gorges Laboratory(SK212001).
文摘Metal-organic frameworks(MOFs)have gained attention in the development of MOFs/polymer hybrid membranes for pervaporation.However,the agglomeration of MOFs particles and interfacial defects limit its further application.In this study,we present a novel approach to fabricate a ZIF-8@PEBAX/PVDF nanocomposite membrane for removing thiophene from the model gasoline by combination of selfassembly and in-situ growth.Firstly,a PVDF supporting membrane was modified to have a negative charge.Next,positively charged zinc ions were attracted onto the negatively charged PVDF supporting membrane through electrostatic interaction.Afterwards,the Zinc ions deposited PVDF membrane was immersed into dimethylimidazole solution to form a uniform ZIF-8 layer.Finally,the ZIF-8 layer was coated with poly(ether-block-amide)(PEBAX)using the pouring method.Experimental results showed that the separating efficiency of the ZIF-8@PEBAX/PVDF nanocomposite membrane was improved significantly compared to that of pristine PEBAX membrane.The optimal permeation flux and enrichment factor of membrane were 27.80 kg(m^(2)h)^(-1)and 6.9,respectively.
基金the National Natural Science Foundation of China (No.20276015) the Natural Science Foundation of HebeiProvince (No.203364)
文摘Thiophene C4H4S and 3-methylthiophene3-MC4H4S are typical thiophenenic sulfur compounds that exist in fluid catalytic cracking FCC gasoline. Oxidation of C4H4S and 3-MC4H4S were conducted in hydrogen peroxide H2O2 and formic acid system over a series of silica gel loaded with metal oxide. The silica gel loaded with copper and cobalt 1:1 oxide was found very active for the model compound oxidation using H2O2formic acid, while the silica gel unloaded with metal oxide was less active. The sulfur removal rate of thiophenes was dif- ferent as solvent was changed. And the conversation of C4H4S and 3-MC4H4S was improved at higher temperature, but reduced when olefin was added. The sulfur removal rate of model sulfur compounds was enhanced when the phase transfer catalyst emulsifier polyethylene glycol octyl phenyl ether or tetrabutylammonium bromideTBAB was added. The sulfur removal rate of simulated gasoline containing 524μg·ml-1 sulfur reached 90%. Interestingly, in a H2O2 and formic acid system with the addition of TBAB, a bromine substitution trend appeared in the oxidation of thiophenes, suggesting the influence of TBAB.
文摘Photocatalytic oxidation kinetics of thiophene in n-octane/water extraction system was studied with fluorine and ferric ion codoped nano-TiO<sub>2</sub>(nano-F<sup>-</sup>/Fe<sup>3+</sup>/TiO<sub>2</sub>) powders used as the photocatalyst.Effects of initial concentration of thiophene and additional dosage of F<sup>-</sup>/Fe<sup>3+</sup>/TiO<sub>2</sub> on the reaction rate constant and half-life were investigated.The results showed that the appropriately added dosage of F<sup>-</sup>/Fe<sup>3+</sup>/TiO<sub>2</sub> was 0.1 g in the 100-mL reaction system and the photooxidative kinetics of thiophene in the presence of F<sup>-</sup>/Fe<sup>3+</sup>/TiO<sub>2</sub> catalyst was of first-order with a rate constant of 0.6508 h<sup>-1</sup> and a half-life of 1.0651 h.The desulfurization rate of thiophene was 98.1%in 5 h and the sulfur content could be reduced from 800 ppm to 15 ppm.The reaction rate constant increased with a decreasing initial concentration of thiophene.
文摘The HY,Hβ,HZSM-5,and SAPO-11 zeolites were investigated in the alkylation reaction of thiophene and olefins.As a result,some sulfur-containing impurities could be converted to higher molecular weight components with their boiling point being in the range of diesel fraction.HZSM-5 had the highest activity and selectivity of desulfurization.At the same time,extensive oligomerization of olefins was not found and coke yield was very low,which could lead to high yield of gasoline products.The main reaction mechanism verifies that the second order alkylation reaction can be carried out on the outer surface and/or pores of the catalyst.The catalytic performance of the HZSM-5 catalyst which is poisoned by 2,4-dimethylquinoline during alkylation to form larger molecules of sulfur compounds is obviously weakened due to the decrease of the acid sites on the outer surface and at the mouth of pores.
基金This project is supported by the National Natural Science Foundation of China.
文摘A novel macrocycle containing thiophene （L） was prepared first by the interaction of 2,5-bis-（chloromethyl）-thiophene （A） and salicylaldehyde to give 2, 5-bis-（2-formylphenoxymethyl）-thiophene （B）, and then by the nontemplate cyclocondensation of 1,3-diaminopropane with （B） followed by a "onepot" reduction without isolation of the diimine intermediate. The corresponding silver complex, AgLClO<sub>4</sub>, was also prepared. The macrocycle was characterized by IR, elemental analysis, MS and <sup>1</sup>HNMR.
文摘The selection and design of an optimal solvent for extractive distillation require reliable vapour-liquid phase equilibrium data and knowledge of extraction mechanisms.Compared with time-consuming experiments,molecular simulation presents great potential in research on the properties of fluids.Therefore,in this work,Gibbs ensemble Monte Carlo was applied to successfully predict the vapour-liquid phase equilibrium data of binary and ternary systems containing benzene,thiophene and N,Ndimethylformamide(DMF) at P=101.3 kPa.The explicit hydrogen version of the transferable potentials for phase equilibria potential model was chosen for benzene and thiophene,whereas the OPLS potential model was selected for DMF.The predicted phase diagrams were compared with experimental data and the UNIQUAC thermodynamic model.A good agreement was obtained,which corroborated the validity of the potential models.In addition,the extraction mechanism was explored by radial distribution function(RDF) of the liquid-phase structure.The RDFs showed that thiophene and benzene shared a similar liquidphase structure because of the intermolecular interaction.The distinct difference between the RDFs of DMF/benzene and those of DMF/thiophene is that the oxygen atom of DMF is more associated with hydrogen atoms of thiophene than that of benzene,which may be responsible for the extraction effect of DMF.
基金Supported by the National Natural Science Foundation of China(No. 2 98730 2 5 )
文摘The second-order nonlinear optical properties of thiophene S,S -dioxides derivatives were studied by using the ZINDO-SOS method. The computed results show that the thiophene S,S -dioxide derivatives exhibit larger second-order polarizabilities than their thiophene precursors. In order to clarify the origin of the different NLO responses among these chromophores, their electron properties and frontier orbital properties were investigated as well. These thiophene S,S -dioxides derivatives are good candidates for their application in electro-optical device due to their high nonlinearities, good thermal and photo stabilities.
基金the National Natural Science Foundation of China(21822810,21838011)the National Key Research and Development Program(2018YFC1902603).
文摘Competition of hydrocarbon compounds with sulfides in gasoline has caused a not very high selectivity of sulfides in adsorption desulfurization so far,resulting in a reduction of catalyst lifetime as well as more sulfur oxide emissions.Tostudy the whole competitive process changing with the increase of the loading,the dynamic competition adsorption mechanism of cyclohexene and thiophene in siliceous faujasite(FAU)zeolite was analyzed by the Monte Carlo simulation.The results showed that with the increase of the loading,thiophene and cyclohexene had different performances before and after the inflection point of 40 molecule/UC.The adsorbates were distributed ideally at optimal sites during the stage that occurred before the inflection point,which is called the“optimal-displacement adsorption”stage.When approaching the inflection point,the competition became apparent and the displacement appeared accordingly,some thiophene molecules at S sites(refers to the sites inside the supercages)were displaced by cyclohexene.After the inflection point,the concentration of adsorbates at W sites(refers to the 12-membered ring connecting the supercages)was significantly reduced,whereas the adsorbates at S sites got more concentrated.The stage some cyclohexene molecules displaced by thiophene and inserted into the center of the supercage can be named as the“insertion-displacement adsorption”stage,and both the adsorption behavior and the competitive relationship became localized when the adsorption amount became saturated.This shift in the competitive adsorption mechanism was due to the sharp increase of interaction energy between the adsorbates.Besides,the increase in temperature and ratio of Si/Al will allow the adsorbates,especially thiophene molecules to occupy more adsorption sites,and it is beneficial to improve the desulfurization selectivity.
基金supported by the National Natural Science Foundation of China(21975116)the Guangdong-Hong Kong-Macao Joint Laboratory(2019B121205001)the Major Program of Guangdong Basic and Applied Research(2019B030302009)。
文摘Lewis acid–base passivation is a significant technique to achieve structural stability of perovskite solar cells(PSCs) by overcoming the issues of wide grain boundaries, crystal defects, and the instability of PSCs. In this work, the combined effects of thiophene with phthalocyanine(Pc) as isomers(S2 and S3)on the photovoltaic performance of PSCs were studied for the first time. Through density functional theory calculations, we confirmed that the position of the S atom in the structure affects Lewis acid–base interactions with under-coordinated Pb^(2+) sites. The morphology of methylammonium lead iodide(MAPbI_(3)) for passivated devices was improved and thin dense layers with compact surface and large grain size were observed, leading to improvement of the charge extraction ability and reduction of non-radiative recombination and the trap density. A highest power conversion efficiency of 18% was achieved for the Pc S3 passivated device, which was 6.69% more than that of the controlled device.Furthermore, the Pcs passivated devices demonstrated remarkable stability under high-moisture and high-temperature conditions.
文摘The reaction mechanism of thiophene on vanadium oxides under FCC operating conditions hadbeen preliminary studied using in-situ FT-IR analysis of thiophene and atmospheric pressure continuousfixed-bed reaction, followed by characterization via pyridine adsorption-temperature programmed desorptionmethod, and FT-IR and XPS spectra. The research had discovered that, under 500℃ thiophene could undergothe redox reaction with V2O5, while being converted into CO, CO2 as well as SO2 with its conversion ratereaching 41.2%. At the same time the oxidation number of vanadium decreased. The existence of a few Brnstedacid centers on V2O5 could lead to an increase of H2S yield among the products derived from the reaction withthiophene.
基金The financial support from the Dean Project of Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology (2013Z009)the Guangxi Natural Science Fund (2014jjAA20079)the Guangdong Province of Quality and Technical Supervision Bureau (2018ZZ01) is greatly appreciated
文摘The mass transfer of thiophene through pervaporation(PV)membranes could be facilitated by certain transitional metal ions like Ag^+,Mn^2+,and Cr^3+thanks to their p complexation with thiophene.In this study,Ag^+,Mn^2+,and Cr^3+ions were loaded onto the polyether block amide(PEBAX)/PAN composite membranes and were tested on the performance for separation of thiophene/n-heptane mixture.Pervaporation test results showed that the pervaporative separation index increased significantly to 73.1%,75.5%,and 97.2%at 30℃for the Ag^+-,Mn2^+-,Cr3^+-loaded PEBAX membranes,respectively,as compared to the pristine PEBAX/PAN composite membrane.
文摘A new method for the synthesis of substituted thiophenes was through intramolecular aldol condensation ofα-oxo ketene dibenzylthioacetals.All products were confirmed with IR, 1 H NMR and elemental analysis.
基金This research was supported by the National Natural Science Foundation of China(No.69637010).
文摘A novel monomer, (trans)-7-[4-N,N-(di-β-hydroxyethyl) amino-benzene]-ethenyl-3,5-dinitro-thiophene (HBDT), was synthesized and characterized. The details of synthesizing the monomer andprepolymer, polyurethane with the monomer covalently incorporated are presented. The prepolymer andpolyurethane exhibited good solubility in common organic solvents. Molecular nonlinear optical properties ofthe monomer (HBDT) substituted thiophene based stilbenes is presented.
基金This work was supported by the Ministry of Science and Technology of China(No.2002CB613402)the National Natural Science Foundation of China(No.50433030).
文摘A series of conjugated copolymers derived from 9-ethylhexyl-2,7-carbazole(Cz)and 4,7-di(4-hexylthien-2-yl)- 2,1,3-benzothiadiazole(DHTBT)was synthesized by Suzuki polycondensation.The photo-and electro-luminescent properties of these polymers were investigated.Efficient energy transfer from the Cz segment to the DHTBT unit occurs even if the DHTBT content as low as 1 mol%.PL emission was red-shifted significantly from 645 nm to 700 nm with the increase in DHTBT content by 1-50 mol%.PL efficiencies decrea...
基金by the National Natural Science Foundation of China under Grant Nos 60676051,60876046,60976048 and 61076065,Tianjin Natural Science Foundation(06TXTJJC14603,07JCYBJC12700)Key Project of the Ministry of Education of China(209007)+2 种基金Tianjin Natural Science Council(10ZCKFGX01900)Scientific Developing Foundation of Tianjin Education Commission(20100723)the Tianjin Key Discipline of Material Physics and Chemistry.
文摘The performance of polymer field-effect transistors is improved by thermal crosslinking of poly(3-hexylthiophene),using ditert butyl peroxide as the crosslinker.The device performance depends on the crosslinker concentration significantly.We obtain an optimal on/off ratio of 105 and the saturate field-effect mobility of 0.34 cm2V−1s−1,by using a suitable ratios of ditert butyl peroxide,0.5 wt%of poly(3-hexylthiophene).The microstructure images show that the crosslinked poly(3-hexylthiophene)active layers simultaneously possess appropriate crystallinity and smooth morphology.Moreover,crosslinking of poly(3-hexylthiophene)prevents the transistors from large threshold voltage shifts under ambient bias-stressing,showing an advantage in encouraging device environmental and operating stability.
文摘The starting 1-phenylbutane-1,3-dione (1) was used as key intermediate for the synthesis of several new thiophene and pyrazole derivatives. The newly synthesized compounds were evaluated for in vitro cytotoxicity against an Ehrlich ascites cells and in vivo cytotoxicity for compound 10d using EAC assay and 5-fluorouracil is used as reference drug. Compounds 7c, e and 10c, d showed significant activity in certain cancer cell and have been targeted for further studies, compound 10d is more effective and showed the highest activity. Structures of the newly prepared compounds were confirmed by both spectral, analytical data and molecular calculations.
