The coordination numbers in the molecular interaction volume model (MIVM) can be calculated from the commonphysical quantities of pure liquid metals. A notable feature of the model lie in its capability to predict the...The coordination numbers in the molecular interaction volume model (MIVM) can be calculated from the commonphysical quantities of pure liquid metals. A notable feature of the model lie in its capability to predict the ther-modynamic properties of solutes in the Zn-Pb-In and Zn-Sn-Cd-Pb dilute solutions using only the binary infinitedilute activity coefficients, and the predicted values are in good agreement with the experimental data of the dilutesolutions.展开更多
Association behavior of ethylene vinyl acetate (EVA) copolymer in foursolvents 1, 2-dichloroethane (DCE), cyclohexane (CYH), xylene (XYL) and chloroform(CF) has been investigated by dilute solution viscometry The crit...Association behavior of ethylene vinyl acetate (EVA) copolymer in foursolvents 1, 2-dichloroethane (DCE), cyclohexane (CYH), xylene (XYL) and chloroform(CF) has been investigated by dilute solution viscometry The critical association concen-tration (C_A) was determined at which the incipient decrease in slope of the η_(sp)/C～ Ccurve in solutions at the dilute regime. Our results showed that whether the CA couldexist depends on solvent property. The values of CA in DCE increase with increasing, oftemperature and vinyl acetate (VA) content in EVA and decreasing of molecular weight ofEVA.展开更多
Excimer formation in pyrenyl labeled polystyrene has been investigated in dilutesolution region. The change of the intensity ratio of excimer to monomer (Ie/Im) with increasingconcentration (C), is interpreted by intr...Excimer formation in pyrenyl labeled polystyrene has been investigated in dilutesolution region. The change of the intensity ratio of excimer to monomer (Ie/Im) with increasingconcentration (C), is interpreted by intrachain and interchain interactions. The double logarithmicPlot of Ie/Im vs C displays two critical points, Cs at about 2.5×10-3g/ml and C+ at about 3.2×10-2g/ml. In dilute region C<Cs, excimer formation may be controlled by intrachain interaction.展开更多
The characteristics of macromolecular chains of cellulose in dilute solutions are discussed. Viscometry was used for the measurement of the intrinsic viscosity [η] of four cellulose samples, which were respectively d...The characteristics of macromolecular chains of cellulose in dilute solutions are discussed. Viscometry was used for the measurement of the intrinsic viscosity [η] of four cellulose samples, which were respectively dissolved in the solvent Tri-ethylenediamine cadmium hydroxide Cadoxen (Cadoxen), Cupriethylenediamine hydroxide(Cuen), iron sodium tartrate complex(EWNN) and N,N-dimethylacetamide(DMAc)with lithium chloride(LiCI, 9% w/w). The intrinsic viscosity of the four solutions decreased in the following manner:[η]DMAc/LiCl】[η]EWNN】[η]Cuen】[η]Cadoxen. The stability of cellulose (Sample α-cellulose) dissolved in solvents Cuen and EWNN was tested by plotting the intrinsic viscosity vs. time. The values of Huggins constant K_H for the cellulose samples dissolved in solvents Cadoxen,Cuen,EWNN and DMAc/LiCl (9% w/w ) were calculated.展开更多
Dilute solution behavior of chitosan was studied in formic acid, acetic acid, lactic acid andhydrochloric acid aqueous solution under different pH values. The reduced viscosities, η_(sp)/C,ofchitosan solutions were d...Dilute solution behavior of chitosan was studied in formic acid, acetic acid, lactic acid andhydrochloric acid aqueous solution under different pH values. The reduced viscosities, η_(sp)/C,ofchitosan solutions were dependent on the properties of acid and pH value of solvents. For a givenchitosan concentration, η^(sp)/C decreased with the increase of acid concentration, or decreasing pHof solvent, indicating shielding effect of excessive acid similar to adding salt into solution. Thestabilities of dilute chitosan solution in formic acid and lactic acid were better than that in acetic acid and hvdrochloric acid.展开更多
The interaction between poly(methymethacrylate) (PMMA) and poly(vinyl chloride) (PVC) has been studied indilute urea solutions of dimethylformamide (DMF) at 28℃ using a dilute solution viscometry method. The results ...The interaction between poly(methymethacrylate) (PMMA) and poly(vinyl chloride) (PVC) has been studied indilute urea solutions of dimethylformamide (DMF) at 28℃ using a dilute solution viscometry method. The results show thatthe polymer mixtures are compatible in DMF solution in the absence of urea. The influence of urea addition on the degree ofcompatibility of the polymer mixtures has been studied in terms of the compatibility parameters (△b_m and △[η]_m). It wasfound that the compatibility of the polymer mixtures is decreased with increasing urea addition, passing through a minimumat 0.5 M urea.展开更多
A novel amphiphile of 4-[4-(4-decyloxyphenylazo) naphthyloxy] butyl trimethylammonium bromide has been synthesized. It can form the stable bilayer in dilute aqueous solution.
The influences of both the volume of PS/toluene solution in the Ubbelohde viscometer and the precision of the time measuring on the viscosity behavior in dilute and extremely dilute concentration region are investigat...The influences of both the volume of PS/toluene solution in the Ubbelohde viscometer and the precision of the time measuring on the viscosity behavior in dilute and extremely dilute concentration region are investigated. It was found that the influence of the former can neglect, but that of the latter is so prominent that the data fluctuate bitterly and linearity of the curve of the reduced viscosity vs. concentration (hsp/c^c) becomes too bad to obey the Huggins equation down to the extremely dilute region, despite the error of the flow times Dt 0.2s, which is permitted by the conventional method of viscosity measurement. Through strict mathematical analyses, it was found that the error (E) of the reduced viscosity is in proportion and inverse proportion to Dt and concentration c, respectively. So the less the concentration, the more the error is. Consequently, a lowest concentration limit cL corresponding to given experimental error may exist and it will be meaningless for further operation below cL because of the great fluctuation of the data. Therefore, it needs to seriously reconsider the application of the conventional method of Ubbelohde viscosity measurement in the extremely dilute polymer solution under traditional conditions because of the great influence of the experimental error.展开更多
The uncertainty of standard solution plays an important role in detection of pesticide residues. It may affect the accuracy of detection results. In this study, the 14 organophosphorus pesticides mixed standard soluti...The uncertainty of standard solution plays an important role in detection of pesticide residues. It may affect the accuracy of detection results. In this study, the 14 organophosphorus pesticides mixed standard solution was used as the material to analyze all the influencing factors for the preparation of mixed standard solution with uncertainty as the only judging index. The preparation uncertainty of mixed standard solution was calculated with the top-down calculation method. In the end, the expanded uncertainty was presented. The results showed that the preparation of mixed standard solution from stock solution with precise pipettes had a relatively low uncertainty.展开更多
The original van Laar's theory has been modified. The internal pressures of components and mixture are expressed by Frank's relation and the excess entropy for mixing of components is also considered. A new ac...The original van Laar's theory has been modified. The internal pressures of components and mixture are expressed by Frank's relation and the excess entropy for mixing of components is also considered. A new activity coefficient equation, which can be satisfactorily applied to polymer solutions, is obtained. The calculated results for the VLE of 179 polymer solutions show that the accuracy of fit is evidently superior to UNIQUAC equation.展开更多
The design and performance prediction of efficient anticorrosion materials is a work full of value,novelty,and challenges.In this work,from the perspective of nanostructure and composition,ZnO-based dilute magnetic so...The design and performance prediction of efficient anticorrosion materials is a work full of value,novelty,and challenges.In this work,from the perspective of nanostructure and composition,ZnO-based dilute magnetic solid solution(DMSs)with hydrophobic micronano network structure was synthesized through the self-induced effect of raw materials,the impact-resistant network structure,complex micro-channels,and densely nested layers resisted electrolyte intrusion.Further,the doping of mixed valence Mn element endowed the solid solution with dilute magnetic properties,so the Lorentz force from micromagnetic field changed the movement path of electrons produced by the anode reaction to improve the corrosion inhibition ability of the protective layer.Under the synergy of morphology and magnetism,the corrosion resistance of the DMSs materials was 555.4%and 173.8%higher than that of epoxy resin and ZnO shielding layer,respectively.Besides,a valuable phenomenon was found that the photocatalytic property of DMSs materials was positively correlated with their corrosive defense.In conclusion,this research provided a novel design idea for new high-efficiency anticorrosion materials.展开更多
The commercialized poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)is usually used as hole transport layers(HTLs)in tin-based perovskite solar cells(TPSCs).However,the further development has been re...The commercialized poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)is usually used as hole transport layers(HTLs)in tin-based perovskite solar cells(TPSCs).However,the further development has been restricted due to the acidity that could damage the stability of TPSCs.Although the PEDOT:PSS solution can be diluted by water to decrease acidity and reduce the cost of device fabrication,the electrical conductivity will decrease obviously in diluted PEDOT:PSS solution.Herein,potassium thiocyanate(KSCN)is selected to regulate the properties of PEDOT:PSS HTLs from the diluted PEDOT:PSS aqueous solution by water with a volume ratio of 1:1 to prepare efficient TPSCs.The effect of KSCN addition on the structure and photoelectrical properties of PEDOT:PSS HTLs and TPSCs have been systematically studied.At the optimal KSCN concentration,the TPSCs based on KSCN-doped PEDOT:PSS HTLs(KSCN-PSCs)demonstrate the champion power conversion efficiency(PCE)of 8.39%,while the reference TPSCs only show a champioan PCE of 6.70%.The further analysis demonstrates that the KSCN additive increases the electrical conductivity of HTLs prepared by the diluted PEDOT:PSS solution,improves the microstructure of perovskite film,and inhibits carrier recombination in TPSCs,leading to the reduced hysteresis effect and enhanced PCE in KSCN-PSCs.This work gives a low-cost and practical strategy to develop a high-quality PEDOT:PSS HTLs from diluted PEDOT:PSS aqueous solution for efficient TPSCs.展开更多
基金This work was supported bv the Joint Fund of the National Natural Science Foundation of China and Baoshan Steel Complex of Shanghai under Crarit No.50274039.
文摘The coordination numbers in the molecular interaction volume model (MIVM) can be calculated from the commonphysical quantities of pure liquid metals. A notable feature of the model lie in its capability to predict the ther-modynamic properties of solutes in the Zn-Pb-In and Zn-Sn-Cd-Pb dilute solutions using only the binary infinitedilute activity coefficients, and the predicted values are in good agreement with the experimental data of the dilutesolutions.
基金This work was supported by the National Natural Science Foundation of China(No.29474168)
文摘Association behavior of ethylene vinyl acetate (EVA) copolymer in foursolvents 1, 2-dichloroethane (DCE), cyclohexane (CYH), xylene (XYL) and chloroform(CF) has been investigated by dilute solution viscometry The critical association concen-tration (C_A) was determined at which the incipient decrease in slope of the η_(sp)/C～ Ccurve in solutions at the dilute regime. Our results showed that whether the CA couldexist depends on solvent property. The values of CA in DCE increase with increasing, oftemperature and vinyl acetate (VA) content in EVA and decreasing of molecular weight ofEVA.
文摘Excimer formation in pyrenyl labeled polystyrene has been investigated in dilutesolution region. The change of the intensity ratio of excimer to monomer (Ie/Im) with increasingconcentration (C), is interpreted by intrachain and interchain interactions. The double logarithmicPlot of Ie/Im vs C displays two critical points, Cs at about 2.5×10-3g/ml and C+ at about 3.2×10-2g/ml. In dilute region C<Cs, excimer formation may be controlled by intrachain interaction.
文摘The characteristics of macromolecular chains of cellulose in dilute solutions are discussed. Viscometry was used for the measurement of the intrinsic viscosity [η] of four cellulose samples, which were respectively dissolved in the solvent Tri-ethylenediamine cadmium hydroxide Cadoxen (Cadoxen), Cupriethylenediamine hydroxide(Cuen), iron sodium tartrate complex(EWNN) and N,N-dimethylacetamide(DMAc)with lithium chloride(LiCI, 9% w/w). The intrinsic viscosity of the four solutions decreased in the following manner:[η]DMAc/LiCl】[η]EWNN】[η]Cuen】[η]Cadoxen. The stability of cellulose (Sample α-cellulose) dissolved in solvents Cuen and EWNN was tested by plotting the intrinsic viscosity vs. time. The values of Huggins constant K_H for the cellulose samples dissolved in solvents Cadoxen,Cuen,EWNN and DMAc/LiCl (9% w/w ) were calculated.
基金The project is supported by the National Natural Science Foundation of China
文摘Dilute solution behavior of chitosan was studied in formic acid, acetic acid, lactic acid andhydrochloric acid aqueous solution under different pH values. The reduced viscosities, η_(sp)/C,ofchitosan solutions were dependent on the properties of acid and pH value of solvents. For a givenchitosan concentration, η^(sp)/C decreased with the increase of acid concentration, or decreasing pHof solvent, indicating shielding effect of excessive acid similar to adding salt into solution. Thestabilities of dilute chitosan solution in formic acid and lactic acid were better than that in acetic acid and hvdrochloric acid.
文摘The interaction between poly(methymethacrylate) (PMMA) and poly(vinyl chloride) (PVC) has been studied indilute urea solutions of dimethylformamide (DMF) at 28℃ using a dilute solution viscometry method. The results show thatthe polymer mixtures are compatible in DMF solution in the absence of urea. The influence of urea addition on the degree ofcompatibility of the polymer mixtures has been studied in terms of the compatibility parameters (△b_m and △[η]_m). It wasfound that the compatibility of the polymer mixtures is decreased with increasing urea addition, passing through a minimumat 0.5 M urea.
文摘A novel amphiphile of 4-[4-(4-decyloxyphenylazo) naphthyloxy] butyl trimethylammonium bromide has been synthesized. It can form the stable bilayer in dilute aqueous solution.
文摘The influences of both the volume of PS/toluene solution in the Ubbelohde viscometer and the precision of the time measuring on the viscosity behavior in dilute and extremely dilute concentration region are investigated. It was found that the influence of the former can neglect, but that of the latter is so prominent that the data fluctuate bitterly and linearity of the curve of the reduced viscosity vs. concentration (hsp/c^c) becomes too bad to obey the Huggins equation down to the extremely dilute region, despite the error of the flow times Dt 0.2s, which is permitted by the conventional method of viscosity measurement. Through strict mathematical analyses, it was found that the error (E) of the reduced viscosity is in proportion and inverse proportion to Dt and concentration c, respectively. So the less the concentration, the more the error is. Consequently, a lowest concentration limit cL corresponding to given experimental error may exist and it will be meaningless for further operation below cL because of the great fluctuation of the data. Therefore, it needs to seriously reconsider the application of the conventional method of Ubbelohde viscosity measurement in the extremely dilute polymer solution under traditional conditions because of the great influence of the experimental error.
文摘The uncertainty of standard solution plays an important role in detection of pesticide residues. It may affect the accuracy of detection results. In this study, the 14 organophosphorus pesticides mixed standard solution was used as the material to analyze all the influencing factors for the preparation of mixed standard solution with uncertainty as the only judging index. The preparation uncertainty of mixed standard solution was calculated with the top-down calculation method. In the end, the expanded uncertainty was presented. The results showed that the preparation of mixed standard solution from stock solution with precise pipettes had a relatively low uncertainty.
基金Supported by the National Natural Science Foundation of China(No.29376236).
文摘The original van Laar's theory has been modified. The internal pressures of components and mixture are expressed by Frank's relation and the excess entropy for mixing of components is also considered. A new activity coefficient equation, which can be satisfactorily applied to polymer solutions, is obtained. The calculated results for the VLE of 179 polymer solutions show that the accuracy of fit is evidently superior to UNIQUAC equation.
基金supported by the National Natural Science Foundation of China(No.21878090)the Opening Project of Material Corrosion and Protection Key Laboratory of Sichuan Province(No.2020CL04).
文摘The design and performance prediction of efficient anticorrosion materials is a work full of value,novelty,and challenges.In this work,from the perspective of nanostructure and composition,ZnO-based dilute magnetic solid solution(DMSs)with hydrophobic micronano network structure was synthesized through the self-induced effect of raw materials,the impact-resistant network structure,complex micro-channels,and densely nested layers resisted electrolyte intrusion.Further,the doping of mixed valence Mn element endowed the solid solution with dilute magnetic properties,so the Lorentz force from micromagnetic field changed the movement path of electrons produced by the anode reaction to improve the corrosion inhibition ability of the protective layer.Under the synergy of morphology and magnetism,the corrosion resistance of the DMSs materials was 555.4%and 173.8%higher than that of epoxy resin and ZnO shielding layer,respectively.Besides,a valuable phenomenon was found that the photocatalytic property of DMSs materials was positively correlated with their corrosive defense.In conclusion,this research provided a novel design idea for new high-efficiency anticorrosion materials.
基金sponsored by Guangzhou Basic and Applied Basic Research Foundation(No.303523)。
文摘The commercialized poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)is usually used as hole transport layers(HTLs)in tin-based perovskite solar cells(TPSCs).However,the further development has been restricted due to the acidity that could damage the stability of TPSCs.Although the PEDOT:PSS solution can be diluted by water to decrease acidity and reduce the cost of device fabrication,the electrical conductivity will decrease obviously in diluted PEDOT:PSS solution.Herein,potassium thiocyanate(KSCN)is selected to regulate the properties of PEDOT:PSS HTLs from the diluted PEDOT:PSS aqueous solution by water with a volume ratio of 1:1 to prepare efficient TPSCs.The effect of KSCN addition on the structure and photoelectrical properties of PEDOT:PSS HTLs and TPSCs have been systematically studied.At the optimal KSCN concentration,the TPSCs based on KSCN-doped PEDOT:PSS HTLs(KSCN-PSCs)demonstrate the champion power conversion efficiency(PCE)of 8.39%,while the reference TPSCs only show a champioan PCE of 6.70%.The further analysis demonstrates that the KSCN additive increases the electrical conductivity of HTLs prepared by the diluted PEDOT:PSS solution,improves the microstructure of perovskite film,and inhibits carrier recombination in TPSCs,leading to the reduced hysteresis effect and enhanced PCE in KSCN-PSCs.This work gives a low-cost and practical strategy to develop a high-quality PEDOT:PSS HTLs from diluted PEDOT:PSS aqueous solution for efficient TPSCs.
