The study of complex properties in a binary mixture of polar liquids has been carried out in the frequency range of 10 MHz to 30 GHz at 293 K and 298 K temperatures using time domain reflectometry.The complex properti...The study of complex properties in a binary mixture of polar liquids has been carried out in the frequency range of 10 MHz to 30 GHz at 293 K and 298 K temperatures using time domain reflectometry.The complex properties of polar liquids in binary mixture give information about the frequency dispersion in the dielectric permittivity(ε')and dielectric loss(ε").The information regarding the orientation of electric dipoles in a polar liquid mixture is given by Kirkwood parameters.The Bruggeman parameters are used as the indicator of liquid1 and liquid2 interaction.Molar entropy(ΔS)and molar enthalpy(ΔH)are also discussed at the end of the paper.展开更多
The Complex permittivity spectra of glycol ether(GE)compounds such as ethylene glycol mono-methyl ether(EGME)with water mixture over entire concentration range and in temperature range of 10-25℃ have been determined ...The Complex permittivity spectra of glycol ether(GE)compounds such as ethylene glycol mono-methyl ether(EGME)with water mixture over entire concentration range and in temperature range of 10-25℃ have been determined using Time Domain Reflectometry(TDR)technique in the frequency range 10MHz to 50 GHz.The complex permittivity spectra for EGME-water were fitted in the Cole-Davidson model.The Static dielectric constant(ε_(0)^(E)),Relaxation time(τ),effective Kirkwood correlation factor(g_(eff)),excess permittivity(ε_(0)),thermodynamic parameters(activation enthalpy and activation entropy)and Bruggeman factor(f_(B))have been calculated by the nonlinear least square fit method.The intermolecular interactions between EGME-water binary mixtures suggest the nonlinear behavior of dielectric parameters.The contribution of hydrogen bonding interactions among the solute-solvent mixtures is confirmed by Excess properties and Bruggeman factor.展开更多
The dielectric properties of binary mixtures of benzylamine-1,2,6-hexantriol mixtures at different volume fractions of 1,2,6-hexanetriol have been measured using Time Domain Reflectometry(TDR)technique in the frequenc...The dielectric properties of binary mixtures of benzylamine-1,2,6-hexantriol mixtures at different volume fractions of 1,2,6-hexanetriol have been measured using Time Domain Reflectometry(TDR)technique in the frequency range of 10 MHz to 30 GHz.Complex permittivity spectra were fitted using Havriliak-Negami equation.By using least square fit method the dielectric parameters such as static dielectric constant(ε_(0)),dielectric constant at high frequency(ε_(∞)),relaxation timeτ(ps)and relaxation distribution parameter(β)were extracted from complex permittivity spectra at 25℃.The intramolecular interaction of different molecules has been discussed using the Kirkwood correlation factor,Bruggeman factor.The Kirkwood correlation factor(gf)and effective Kirkwood correlation factor(g^(eff))indicate the dipole ordering of the binary mixtures.展开更多
Static permittivity(ε),refractive index(n)and density(ρ)of binary mixtures of ethylene glycol mono phenyl ether(EGMPE)with 1-butanol(1-BuOH)over the entire range of mole fraction and at temperatures(T=303:15,313.15 ...Static permittivity(ε),refractive index(n)and density(ρ)of binary mixtures of ethylene glycol mono phenyl ether(EGMPE)with 1-butanol(1-BuOH)over the entire range of mole fraction and at temperatures(T=303:15,313.15 and 323.15 K)have been measured.From the experimental data,parameters such as excess static permittivity(ε^(E)),excess permittivity at optical frequency(ε^(E)_(∞)),effective Kirkwood correlation factor(g^(eff)),corrective Kirkwood correlation factor(g^(f))and Bruggeman factor(f^(b))have been calculated to obtain qualitative and quantitative information about the complex formation through H-bond in binary system.In order to predict the static permittivity of polar–polar binary mixtures six mixing rules were applied and for refractive index five mixing rule were applied.Experimental results of permittivity(ε)and refractive index(n)are compared with those obtained from theoretical calculations.Excess parameters were fitted to the Redlich–Kister type polynomial equation.展开更多
Temperature dependence of the dielectric constant of oleic acid with different degrees of puritywas measured in the 233-313 K range.It was observed that the presence of impurities(palmiticand linolenic acids)strongly ...Temperature dependence of the dielectric constant of oleic acid with different degrees of puritywas measured in the 233-313 K range.It was observed that the presence of impurities(palmiticand linolenic acids)strongly influences the dielectric constant,melting point and dipole moment of the oleic acid.The values of apparent dipole moment and the Kirkwood correlation parameterswere evaluated using the Kirkwood's model and were estimated to be about 1.20,1.61 and 2.27 D,respectively for 60,90 and 97 wt%oleic acid.展开更多
The time-domain reflectometry technique was exercised to assess the complex permittivities of 1-chloropropane and ethanol along with their binary mixture in the frequency range of 10MHz–50 GHz and in the temperature ...The time-domain reflectometry technique was exercised to assess the complex permittivities of 1-chloropropane and ethanol along with their binary mixture in the frequency range of 10MHz–50 GHz and in the temperature range of 10–25℃.Dielectric parameters like static dielectric permittivity(ε_(0))and relaxation time(τ)have been acquired by the least-square-fit method.The obtained assessments of static permittivity and relaxation time were used to compute various dielectric parameters like excess dielectric constant,excess relaxation time,Kirkwood correlation factor and thermodynamic parameters.The experimental outcome illustrates the nonlinear variations in dielectric permittivity,relaxation time and authenticates the structural formation due to intermolecular interaction between 1-chloropropane and ethanol.Molecular rotary motion and dipole reorientation movements of these complex systems are presented in agreement with the molar entropy and enthalpy.展开更多
We present the isothermal susceptibility(XT)for the typical binary polycondensation system of Af-Bg type,and relate XT to the weight-average degree of polymerization in terms of the Kirkwood-Buff(KB)theory.The investi...We present the isothermal susceptibility(XT)for the typical binary polycondensation system of Af-Bg type,and relate XT to the weight-average degree of polymerization in terms of the Kirkwood-Buff(KB)theory.The investigation is based on a new expression of XT for mixtures,which is still expressed by the KB integrals(KBIs)but endowed with an explicit physical interpretation.For polymerization systems,it is proposed that the KBIs can be further decomposed according to whether there exists a bond between particles when conversions(extents of reaction)of functional groups are incorporated into the KBIs.In this way,XT is directly decomposed into its relevant components as well.This is especially useful to reveal the relationship between local structures and average properties of various polymerization systems.As a consequence,the effect of polymerization on XT is greatly simplified in comparison with the free energy route.Therefore,we have provided a very simple method to carry out some thermodynamic properties of polymerization systems.展开更多
Using time domain reflectometry (TDR),dielectric relaxation studies were carried out on binary mixtures of amides (N-methylformamide (NMF) and N,N-dimethylformamide (DMF)) with alcohols (1-butanol,1-pentanol,1-hexanol...Using time domain reflectometry (TDR),dielectric relaxation studies were carried out on binary mixtures of amides (N-methylformamide (NMF) and N,N-dimethylformamide (DMF)) with alcohols (1-butanol,1-pentanol,1-hexanol,1-heptanol,1-octanol,and 1-decanol) for various concentrations over the frequency range from 10 MHz to 10 GHz at 303 K. The Kirkwood correlation factor and excess dielectric constant properties were determined and discussed to yield information on the molecular interactions of the systems. The relaxation time varied with the chain length of alcohols and substituted amides were noticed. The Bruggeman plot shows a deviation from linearity. This deviation was attributed to some sort of molecular interaction which may take place between the alcohols and substituted amides. The excess static permittivity and excess inverse relaxation time values varied from negative to positive for all the systems indicating that the solute-solvent interaction existed between alcohols and substituted amides for all the dynamics of the mixture.展开更多
基金The Department of Science and Technology,New Delhi is gratefully acknowledged(Project no.SR/S2/LOP-25/2007)for laboratory facility.We are thankful to A.C.Kumbharkhane for providing TDR facility and Dr.S.C.Mehrotra,Ramanujan Chair Professor,Department of Computer Science and IT,Dr.B.A.M.University,Aurangabad for their valuable discussions and suggestions.
文摘The study of complex properties in a binary mixture of polar liquids has been carried out in the frequency range of 10 MHz to 30 GHz at 293 K and 298 K temperatures using time domain reflectometry.The complex properties of polar liquids in binary mixture give information about the frequency dispersion in the dielectric permittivity(ε')and dielectric loss(ε").The information regarding the orientation of electric dipoles in a polar liquid mixture is given by Kirkwood parameters.The Bruggeman parameters are used as the indicator of liquid1 and liquid2 interaction.Molar entropy(ΔS)and molar enthalpy(ΔH)are also discussed at the end of the paper.
基金This work was supported by the Department of Science and Technology,New Delhi(Project No.DST PROJECTSB/S2/LOP-032/2013)as well as School of Physical Sciences,SRTM University,Nanded,India for providing necessary facilities。
文摘The Complex permittivity spectra of glycol ether(GE)compounds such as ethylene glycol mono-methyl ether(EGME)with water mixture over entire concentration range and in temperature range of 10-25℃ have been determined using Time Domain Reflectometry(TDR)technique in the frequency range 10MHz to 50 GHz.The complex permittivity spectra for EGME-water were fitted in the Cole-Davidson model.The Static dielectric constant(ε_(0)^(E)),Relaxation time(τ),effective Kirkwood correlation factor(g_(eff)),excess permittivity(ε_(0)),thermodynamic parameters(activation enthalpy and activation entropy)and Bruggeman factor(f_(B))have been calculated by the nonlinear least square fit method.The intermolecular interactions between EGME-water binary mixtures suggest the nonlinear behavior of dielectric parameters.The contribution of hydrogen bonding interactions among the solute-solvent mixtures is confirmed by Excess properties and Bruggeman factor.
基金New Delhi is gratefully acknowledged(project No.SR/S2/LOP-25/2007)for laboratory facility.
文摘The dielectric properties of binary mixtures of benzylamine-1,2,6-hexantriol mixtures at different volume fractions of 1,2,6-hexanetriol have been measured using Time Domain Reflectometry(TDR)technique in the frequency range of 10 MHz to 30 GHz.Complex permittivity spectra were fitted using Havriliak-Negami equation.By using least square fit method the dielectric parameters such as static dielectric constant(ε_(0)),dielectric constant at high frequency(ε_(∞)),relaxation timeτ(ps)and relaxation distribution parameter(β)were extracted from complex permittivity spectra at 25℃.The intramolecular interaction of different molecules has been discussed using the Kirkwood correlation factor,Bruggeman factor.The Kirkwood correlation factor(gf)and effective Kirkwood correlation factor(g^(eff))indicate the dipole ordering of the binary mixtures.
基金Experimental facilities developed using financial assistance provided by Department of Sciences and Technology(DST),New Delhi through the DST-FIST(Level-I)project(SR/FST/PSI-001/2006)University Grant Commission(UGC),New Delhi through major research project(37-159/2009(SR))DRS-SAP program grant[No.F.530/10/DRS/2010(SAP-I)]have been utilized to carry out this work and it is gratefully acknowledged.
文摘Static permittivity(ε),refractive index(n)and density(ρ)of binary mixtures of ethylene glycol mono phenyl ether(EGMPE)with 1-butanol(1-BuOH)over the entire range of mole fraction and at temperatures(T=303:15,313.15 and 323.15 K)have been measured.From the experimental data,parameters such as excess static permittivity(ε^(E)),excess permittivity at optical frequency(ε^(E)_(∞)),effective Kirkwood correlation factor(g^(eff)),corrective Kirkwood correlation factor(g^(f))and Bruggeman factor(f^(b))have been calculated to obtain qualitative and quantitative information about the complex formation through H-bond in binary system.In order to predict the static permittivity of polar–polar binary mixtures six mixing rules were applied and for refractive index five mixing rule were applied.Experimental results of permittivity(ε)and refractive index(n)are compared with those obtained from theoretical calculations.Excess parameters were fitted to the Redlich–Kister type polynomial equation.
基金FFS acknowledges the support from MCT/CNPqEdital 14/2011(process.482495/2011-1)and theauthors thank the Brazilian institutions CAPES,FUNCAP,FAPESPA and CNPq for financial sup-port.Authors also acknowledge Dr.Jeanlex Sousafor a critical reading of the manuscript.
文摘Temperature dependence of the dielectric constant of oleic acid with different degrees of puritywas measured in the 233-313 K range.It was observed that the presence of impurities(palmiticand linolenic acids)strongly influences the dielectric constant,melting point and dipole moment of the oleic acid.The values of apparent dipole moment and the Kirkwood correlation parameterswere evaluated using the Kirkwood's model and were estimated to be about 1.20,1.61 and 2.27 D,respectively for 60,90 and 97 wt%oleic acid.
基金the Department of Science and Technology(DST),New Delhi,is gratefully acknowledged(Project No.DST PROJECT-SB/S2/LOP-032/2013).
文摘The time-domain reflectometry technique was exercised to assess the complex permittivities of 1-chloropropane and ethanol along with their binary mixture in the frequency range of 10MHz–50 GHz and in the temperature range of 10–25℃.Dielectric parameters like static dielectric permittivity(ε_(0))and relaxation time(τ)have been acquired by the least-square-fit method.The obtained assessments of static permittivity and relaxation time were used to compute various dielectric parameters like excess dielectric constant,excess relaxation time,Kirkwood correlation factor and thermodynamic parameters.The experimental outcome illustrates the nonlinear variations in dielectric permittivity,relaxation time and authenticates the structural formation due to intermolecular interaction between 1-chloropropane and ethanol.Molecular rotary motion and dipole reorientation movements of these complex systems are presented in agreement with the molar entropy and enthalpy.
基金supported by the Natural Science Foundation of Hebei Province,China(No.B2022201050)the Interdisciplinary Research Program of Natural Science of Hebei University,China(No.DXK202112).
文摘We present the isothermal susceptibility(XT)for the typical binary polycondensation system of Af-Bg type,and relate XT to the weight-average degree of polymerization in terms of the Kirkwood-Buff(KB)theory.The investigation is based on a new expression of XT for mixtures,which is still expressed by the KB integrals(KBIs)but endowed with an explicit physical interpretation.For polymerization systems,it is proposed that the KBIs can be further decomposed according to whether there exists a bond between particles when conversions(extents of reaction)of functional groups are incorporated into the KBIs.In this way,XT is directly decomposed into its relevant components as well.This is especially useful to reveal the relationship between local structures and average properties of various polymerization systems.As a consequence,the effect of polymerization on XT is greatly simplified in comparison with the free energy route.Therefore,we have provided a very simple method to carry out some thermodynamic properties of polymerization systems.
文摘Using time domain reflectometry (TDR),dielectric relaxation studies were carried out on binary mixtures of amides (N-methylformamide (NMF) and N,N-dimethylformamide (DMF)) with alcohols (1-butanol,1-pentanol,1-hexanol,1-heptanol,1-octanol,and 1-decanol) for various concentrations over the frequency range from 10 MHz to 10 GHz at 303 K. The Kirkwood correlation factor and excess dielectric constant properties were determined and discussed to yield information on the molecular interactions of the systems. The relaxation time varied with the chain length of alcohols and substituted amides were noticed. The Bruggeman plot shows a deviation from linearity. This deviation was attributed to some sort of molecular interaction which may take place between the alcohols and substituted amides. The excess static permittivity and excess inverse relaxation time values varied from negative to positive for all the systems indicating that the solute-solvent interaction existed between alcohols and substituted amides for all the dynamics of the mixture.
