Tatiana Psurek - Academia.edu (original) (raw)
Papers by Tatiana Psurek
Chem Phys, 2002
Two relaxation processes, involving dc conductivity and the glass (alpha) structural relaxation, ... more Two relaxation processes, involving dc conductivity and the glass (alpha) structural relaxation, respectively, were measured in the low-molecular-weight glass-forming liquid, bisphenol- A-propoxylate(1 PO/phenol)diglycidylether, by dielectric spectroscopy, as a function of temperature and pressure. We focused on the correlation between dc conductivity and the alpha-relaxation time, proving that the fractional Debye-Stokes-Einstein relation is valid for both isobaric and isothermal data. The
Regioregular effect transistor applications. While, the electrical mobility properties of P3HT ha... more Regioregular effect transistor applications. While, the electrical mobility properties of P3HT have been examined^ the dielectric poly(3-hexylthiophene) (P3HT) is a material typically used as an organic semiconductor in thin film field- relaxation processes have not been systematically studied. We investigated the dielectric response of P3HT films in the temperature range of 240 K to 315 K and at frequencies up to 12 GHz. In the low frequency range P3HT shows a semi-conducting character and the overall dielectric response is dominated by dc-conductivity with Ea = 17 kJ/mol. The apparent semi-conducting character cease at certain frequency above which, the material becomes a dielectric. At room temperature the semi-conducting to dielectric transition takes place at about 5 kHz. In the range of 10 kHz to 12 GHz the dielectric dispersion is insignificant and the dielectric constant is about 4. The dielectric relaxation process, with tau = 3*10-5s and Ea = 24 kJ/mol, can be attributed t...
NATO Science Series II: Mathematics, Physics and Chemistry, 2005
... STELLA HENSEL-BIELOWKA, MONIKA SEKULA, SEBASTIAN PAWLUS, TATIANA PSUREK AND MARIAN PALUCH Ins... more ... STELLA HENSEL-BIELOWKA, MONIKA SEKULA, SEBASTIAN PAWLUS, TATIANA PSUREK AND MARIAN PALUCH Institute of Physics, Silesian University ... Meier, G., Gerharz, B., Boese, D. and Fischer, EW (1990) Dynamical processes in organic glassforming van der Waals ...
Physical review. E, Statistical, nonlinear, and soft matter physics, 2001
From temperature studies at ambient pressure, it was pointed out for several glass-forming liquid... more From temperature studies at ambient pressure, it was pointed out for several glass-forming liquids that the alpha-relaxation time (tau) can be related to the dc-ionic conductivity (sigma) through the phenomenological fractional Debye-Stokes-Einstein (DSE) equation. In the present paper we test the validity of fractional DSE equation for relaxation data obtained from pressure variable experiments. To this end we carried out broadband dielectric measurements (10 mHz-10 MHz) in a wide range of pressures (0.1-300 MPa). The material under study were N,N-diglycidyl-4-glycidyloxyaniline and N,N-diglycidylaniline. As a result we found that the fractional DSE equation is also obeyed for pressure pathways.
MRS Proceedings, 2005
Complex impedance and conductivity were measured for regioregular poly(3hexylthiophene) (P3HT) at... more Complex impedance and conductivity were measured for regioregular poly(3hexylthiophene) (P3HT) at alternating current (AC) voltages using a waveform technique. The waveforms were Fourier transformed from time domain to frequency domain and analyzed at fundamental and higher order harmonic frequencies. It was found that the impedance of the semi-conducting P3HT decreases with increasing electric field strength. The non-linear charge transport is dominated by a third harmonic response that originates from extended polarizability of π-type electronic states. The third order non-linear conductivity can be used to quantify the effect of an electric field on the conduction mechanism and to correlate the intrinsic charge carriers mobility with molecular structure.
Physical Review E, 2006
Recent measurements have suggested that the antiplasticizing effect of glycerol on trehalose can ... more Recent measurements have suggested that the antiplasticizing effect of glycerol on trehalose can significantly increase the preservation times of proteins stored in this type of preservative formulation. In order to better understand the physical origin of this phenomenon, we examine the nature of antiplasticization in trehalose-glycerol mixtures by dielectric spectroscopy. These measurements cover a broad frequency range between 40 Hz to 18 GHz ͑covering the secondary relaxation range of the fragile glass-former trehalose and the primary relaxation range of the strong glass-former glycerol͒ and a temperature ͑T͒ range bracketing room temperature ͑220 K to 350 K͒. The Havriliak-Negami function precisely fits our relaxation data and allows us to determine the temperature and composition dependence of the relaxation time describing a relative fast dielectric relaxation process appropriate to the characterization of antiplasticization. We observe that increasing the glycerol concentration at fixed T increases ͑i.e., the extent of antiplasticization͒ until a temperature dependent critical "plasticization concentration" x wp is reached. At a fixed concentration, we find a temperature at which antiplasticization first occurs upon cooling and we designate this as the "antiplasticization temperature," T ant . The ratio of the values for the mixture and pure trehalose is found to provide a useful measure of the extent of antiplasticization, and we explore other potential measures of antiplasticization relating to the dielectric strength.
Physical Review E, 2004
Dielectric spectroscopy was employed to study the effects of water on the primary ␣-relaxation an... more Dielectric spectroscopy was employed to study the effects of water on the primary ␣-relaxation and the secondary -relaxation of xylitol. The measurements were made on anhydrous xylitol and mixtures of xylitol with water with three different water concentrations over a temperature range from 173 K to 293 K. The ␣-relaxation speeds up with increasing concentration of water in xylitol, whereas the rate of the -relaxation is essentially unchanged. Some systematic differences in the behavior of ␣-relaxation for anhydrous xylitol and the mixtures were observed. Our findings confirm all the observations of Nozaki et al. [R. Nozaki, H. Zenitani, A. Minoguchi, and K. Kitai, J. Non-Cryst. Solids 307, 349 (2002)] in sorbitol/water mixtures. Effects of water on both the ␣and -relaxation dynamics in xylitol and sorbitol are explained by using the coupling model.
Physical Review B, 2005
The  relaxation is a principal source of information about the dynamics in the glassy state; how... more The  relaxation is a principal source of information about the dynamics in the glassy state; however, the nature of this process remains a controversial issue. In this paper, we show that properties of the  relaxation measured below T g are sensitive to the structure of the glass; that is, the thermodynamic path from the equilibrium liquid strongly affects the  relaxation times, their distribution, and the activation energy quantifying their temperature dependence. These results support the idea that the Johari-Goldstein  process is the precursor to the structural relaxation transpiring at longer times. We discuss the experimental findings in light of the heterogeneous and homogeneous scenarios for the  process.
Physica A: Statistical Mechanics and its Applications, 2004
Dielectric measurements of 4,4 -methylenebis (N; N -diglicydilaniline) (MBDGA) have been carried ... more Dielectric measurements of 4,4 -methylenebis (N; N -diglicydilaniline) (MBDGA) have been carried out along both pressure and temperature pathways. The phenomenon of decoupling between the DC-conductivity and the structural ( -) relaxation time has been studied. We found that the exponent s in the fractional Debye-Stokes-Einstein relation is both temperature and pressure independent, and its value can be determined from the ratio of activation volumes for the DC-conductivity relaxation and the structural relaxation process, respectively. The results for MBDGA have been compared with results previously obtained for similar epoxies, i.e., N; N -diglycidylaniline and N; N -diglycidyl-4-glycidyloxyaniline. A correlation between the molecular size and the fractional exponent has been established.
Journal of Physics: Condensed Matter, 2002
Ionic conductivity data and structural relaxation times for poly(phenyl glycidyl ether)-co-formal... more Ionic conductivity data and structural relaxation times for poly(phenyl glycidyl ether)-co-formaldehyde (PPGE) are compared for the supercooled liquid under aw ide ra nge of temperatures and pressures. Conformance to the fractional Debye-Stokes-Einstein (fDSE) relation was observed under all conditions. The fDSE exponent, =0.81, provides an estimate of the relative magnitude of the activation volumes for conductivity and dielectric relaxation. The smaller activation volume for the forme rs uggests less free volume is necessary to accommodate ion diffusion in the PPG Et han that require df or dielectric relaxation. We also fit the combined temperature and pressure dependences of both the conductivity and relaxation times to the Avramov equation.
The Journal of Chemical Physics, 2000
The pressure and temperature dependent dielectric relaxation times are compared with the predicti... more The pressure and temperature dependent dielectric relaxation times are compared with the predictions of the model proposed by Avramov. Remarkable agreement is found in whole P and T plane. It was also pointed out that the tested model predicts no pressure effect on fragility and nonlinear character of pressure dependence of glass transition temperature. Our data provide also an assessment of the generalized Vogel-Fulcher-Tammann ͑VFT͒ law. However, it is inferred that the generalized VFT law is not able to accurately reproduce the surface described by experimental relaxation times. Additionally, isothermal data are analyzed by the pressure counterpart of the temperature VFT law. The isothermal data expressed in terms of the reduced relaxation time and reduced pressure form a master curve.
The Journal of Chemical Physics, 2002
Two relaxation processes, involving dc conductivity and the glass ͑␣͒ structural relaxation, resp... more Two relaxation processes, involving dc conductivity and the glass ͑␣͒ structural relaxation, respectively, were measured in the low-molecular-weight glass-forming liquid, bisphenol-A-propoxylate͑1 PO/phenol͒diglycidylether, by dielectric spectroscopy, as a function of temperature and pressure. We focused on the correlation between dc conductivity and the ␣-relaxation time, proving that the fractional Debye-Stokes-Einstein relation is valid for both isobaric and isothermal data. The value of the exponent was independent of both temperature and pressure, and related to the ratio of the apparent activation volume of the relaxation processes being considered. The shape of the dielectric loss ␣ peak did not change with either temperature or pressure; i.e., frequencytemperature-pressure superposition was valid in the vicinity of the glass transition.
The Journal of Physical Chemistry B, 2008
Additives to polymeric materials can lead to appreciable changes in the rates of relaxation and r... more Additives to polymeric materials can lead to appreciable changes in the rates of relaxation and reaction in these mixtures that can profoundly alter material properties and function. We develop a general theoretical framework for quantifying changes in the "high-frequency" relaxation dynamics of mixtures based on classical transition state theory, in conjunction with mathematical statements regarding the dependence of the entropy (S + ) and enthalpy (E + ) of activation of the high-frequency relaxation time on diluent mass fraction, x w . Specifically, we deduce a general classification scheme for diluents based on a consideration of the sign of the differential change in S + and E + with x w . Two of these classes of diluents exhibit a transition from plasticization to antiplasticization (defined specifically as a speeding up or slowing down of relaxation relative to the pure system, respectively) upon varying temperature through an "antiplasticization" temperature, T anti . Extensive dielectric relaxation measurements on polycarbonate (PC) as a function of temperature and diluent (Aroclor) concentration are utilized to illustrate our theoretical model, and we focus particularly on the Arrhenius " " dielectric relaxation process of these mixtures. Many aspects of our scheme for quantifying changes in the high-frequency dynamics of mixtures are rationalized by our mixture model. In particular, we show that the dilution of PC by Aroclor is consistent with a theoretically predicted (one of the two antiplasticization mixture classes mentioned above) transition from antiplasticization to plasticization with decreasing temperature. We briefly compare our findings from dielectric measurements with those from elastic incoherent neutron scattering and dynamical-mechanical measurements, providing further evidence for the antiplasticizationto-plasticization transition phenomena that we observe in our high-frequency dielectric measurements.
Chem Phys, 2002
Two relaxation processes, involving dc conductivity and the glass (alpha) structural relaxation, ... more Two relaxation processes, involving dc conductivity and the glass (alpha) structural relaxation, respectively, were measured in the low-molecular-weight glass-forming liquid, bisphenol- A-propoxylate(1 PO/phenol)diglycidylether, by dielectric spectroscopy, as a function of temperature and pressure. We focused on the correlation between dc conductivity and the alpha-relaxation time, proving that the fractional Debye-Stokes-Einstein relation is valid for both isobaric and isothermal data. The
Regioregular effect transistor applications. While, the electrical mobility properties of P3HT ha... more Regioregular effect transistor applications. While, the electrical mobility properties of P3HT have been examined^ the dielectric poly(3-hexylthiophene) (P3HT) is a material typically used as an organic semiconductor in thin film field- relaxation processes have not been systematically studied. We investigated the dielectric response of P3HT films in the temperature range of 240 K to 315 K and at frequencies up to 12 GHz. In the low frequency range P3HT shows a semi-conducting character and the overall dielectric response is dominated by dc-conductivity with Ea = 17 kJ/mol. The apparent semi-conducting character cease at certain frequency above which, the material becomes a dielectric. At room temperature the semi-conducting to dielectric transition takes place at about 5 kHz. In the range of 10 kHz to 12 GHz the dielectric dispersion is insignificant and the dielectric constant is about 4. The dielectric relaxation process, with tau = 3*10-5s and Ea = 24 kJ/mol, can be attributed t...
NATO Science Series II: Mathematics, Physics and Chemistry, 2005
... STELLA HENSEL-BIELOWKA, MONIKA SEKULA, SEBASTIAN PAWLUS, TATIANA PSUREK AND MARIAN PALUCH Ins... more ... STELLA HENSEL-BIELOWKA, MONIKA SEKULA, SEBASTIAN PAWLUS, TATIANA PSUREK AND MARIAN PALUCH Institute of Physics, Silesian University ... Meier, G., Gerharz, B., Boese, D. and Fischer, EW (1990) Dynamical processes in organic glassforming van der Waals ...
Physical review. E, Statistical, nonlinear, and soft matter physics, 2001
From temperature studies at ambient pressure, it was pointed out for several glass-forming liquid... more From temperature studies at ambient pressure, it was pointed out for several glass-forming liquids that the alpha-relaxation time (tau) can be related to the dc-ionic conductivity (sigma) through the phenomenological fractional Debye-Stokes-Einstein (DSE) equation. In the present paper we test the validity of fractional DSE equation for relaxation data obtained from pressure variable experiments. To this end we carried out broadband dielectric measurements (10 mHz-10 MHz) in a wide range of pressures (0.1-300 MPa). The material under study were N,N-diglycidyl-4-glycidyloxyaniline and N,N-diglycidylaniline. As a result we found that the fractional DSE equation is also obeyed for pressure pathways.
MRS Proceedings, 2005
Complex impedance and conductivity were measured for regioregular poly(3hexylthiophene) (P3HT) at... more Complex impedance and conductivity were measured for regioregular poly(3hexylthiophene) (P3HT) at alternating current (AC) voltages using a waveform technique. The waveforms were Fourier transformed from time domain to frequency domain and analyzed at fundamental and higher order harmonic frequencies. It was found that the impedance of the semi-conducting P3HT decreases with increasing electric field strength. The non-linear charge transport is dominated by a third harmonic response that originates from extended polarizability of π-type electronic states. The third order non-linear conductivity can be used to quantify the effect of an electric field on the conduction mechanism and to correlate the intrinsic charge carriers mobility with molecular structure.
Physical Review E, 2006
Recent measurements have suggested that the antiplasticizing effect of glycerol on trehalose can ... more Recent measurements have suggested that the antiplasticizing effect of glycerol on trehalose can significantly increase the preservation times of proteins stored in this type of preservative formulation. In order to better understand the physical origin of this phenomenon, we examine the nature of antiplasticization in trehalose-glycerol mixtures by dielectric spectroscopy. These measurements cover a broad frequency range between 40 Hz to 18 GHz ͑covering the secondary relaxation range of the fragile glass-former trehalose and the primary relaxation range of the strong glass-former glycerol͒ and a temperature ͑T͒ range bracketing room temperature ͑220 K to 350 K͒. The Havriliak-Negami function precisely fits our relaxation data and allows us to determine the temperature and composition dependence of the relaxation time describing a relative fast dielectric relaxation process appropriate to the characterization of antiplasticization. We observe that increasing the glycerol concentration at fixed T increases ͑i.e., the extent of antiplasticization͒ until a temperature dependent critical "plasticization concentration" x wp is reached. At a fixed concentration, we find a temperature at which antiplasticization first occurs upon cooling and we designate this as the "antiplasticization temperature," T ant . The ratio of the values for the mixture and pure trehalose is found to provide a useful measure of the extent of antiplasticization, and we explore other potential measures of antiplasticization relating to the dielectric strength.
Physical Review E, 2004
Dielectric spectroscopy was employed to study the effects of water on the primary ␣-relaxation an... more Dielectric spectroscopy was employed to study the effects of water on the primary ␣-relaxation and the secondary -relaxation of xylitol. The measurements were made on anhydrous xylitol and mixtures of xylitol with water with three different water concentrations over a temperature range from 173 K to 293 K. The ␣-relaxation speeds up with increasing concentration of water in xylitol, whereas the rate of the -relaxation is essentially unchanged. Some systematic differences in the behavior of ␣-relaxation for anhydrous xylitol and the mixtures were observed. Our findings confirm all the observations of Nozaki et al. [R. Nozaki, H. Zenitani, A. Minoguchi, and K. Kitai, J. Non-Cryst. Solids 307, 349 (2002)] in sorbitol/water mixtures. Effects of water on both the ␣and -relaxation dynamics in xylitol and sorbitol are explained by using the coupling model.
Physical Review B, 2005
The  relaxation is a principal source of information about the dynamics in the glassy state; how... more The  relaxation is a principal source of information about the dynamics in the glassy state; however, the nature of this process remains a controversial issue. In this paper, we show that properties of the  relaxation measured below T g are sensitive to the structure of the glass; that is, the thermodynamic path from the equilibrium liquid strongly affects the  relaxation times, their distribution, and the activation energy quantifying their temperature dependence. These results support the idea that the Johari-Goldstein  process is the precursor to the structural relaxation transpiring at longer times. We discuss the experimental findings in light of the heterogeneous and homogeneous scenarios for the  process.
Physica A: Statistical Mechanics and its Applications, 2004
Dielectric measurements of 4,4 -methylenebis (N; N -diglicydilaniline) (MBDGA) have been carried ... more Dielectric measurements of 4,4 -methylenebis (N; N -diglicydilaniline) (MBDGA) have been carried out along both pressure and temperature pathways. The phenomenon of decoupling between the DC-conductivity and the structural ( -) relaxation time has been studied. We found that the exponent s in the fractional Debye-Stokes-Einstein relation is both temperature and pressure independent, and its value can be determined from the ratio of activation volumes for the DC-conductivity relaxation and the structural relaxation process, respectively. The results for MBDGA have been compared with results previously obtained for similar epoxies, i.e., N; N -diglycidylaniline and N; N -diglycidyl-4-glycidyloxyaniline. A correlation between the molecular size and the fractional exponent has been established.
Journal of Physics: Condensed Matter, 2002
Ionic conductivity data and structural relaxation times for poly(phenyl glycidyl ether)-co-formal... more Ionic conductivity data and structural relaxation times for poly(phenyl glycidyl ether)-co-formaldehyde (PPGE) are compared for the supercooled liquid under aw ide ra nge of temperatures and pressures. Conformance to the fractional Debye-Stokes-Einstein (fDSE) relation was observed under all conditions. The fDSE exponent, =0.81, provides an estimate of the relative magnitude of the activation volumes for conductivity and dielectric relaxation. The smaller activation volume for the forme rs uggests less free volume is necessary to accommodate ion diffusion in the PPG Et han that require df or dielectric relaxation. We also fit the combined temperature and pressure dependences of both the conductivity and relaxation times to the Avramov equation.
The Journal of Chemical Physics, 2000
The pressure and temperature dependent dielectric relaxation times are compared with the predicti... more The pressure and temperature dependent dielectric relaxation times are compared with the predictions of the model proposed by Avramov. Remarkable agreement is found in whole P and T plane. It was also pointed out that the tested model predicts no pressure effect on fragility and nonlinear character of pressure dependence of glass transition temperature. Our data provide also an assessment of the generalized Vogel-Fulcher-Tammann ͑VFT͒ law. However, it is inferred that the generalized VFT law is not able to accurately reproduce the surface described by experimental relaxation times. Additionally, isothermal data are analyzed by the pressure counterpart of the temperature VFT law. The isothermal data expressed in terms of the reduced relaxation time and reduced pressure form a master curve.
The Journal of Chemical Physics, 2002
Two relaxation processes, involving dc conductivity and the glass ͑␣͒ structural relaxation, resp... more Two relaxation processes, involving dc conductivity and the glass ͑␣͒ structural relaxation, respectively, were measured in the low-molecular-weight glass-forming liquid, bisphenol-A-propoxylate͑1 PO/phenol͒diglycidylether, by dielectric spectroscopy, as a function of temperature and pressure. We focused on the correlation between dc conductivity and the ␣-relaxation time, proving that the fractional Debye-Stokes-Einstein relation is valid for both isobaric and isothermal data. The value of the exponent was independent of both temperature and pressure, and related to the ratio of the apparent activation volume of the relaxation processes being considered. The shape of the dielectric loss ␣ peak did not change with either temperature or pressure; i.e., frequencytemperature-pressure superposition was valid in the vicinity of the glass transition.
The Journal of Physical Chemistry B, 2008
Additives to polymeric materials can lead to appreciable changes in the rates of relaxation and r... more Additives to polymeric materials can lead to appreciable changes in the rates of relaxation and reaction in these mixtures that can profoundly alter material properties and function. We develop a general theoretical framework for quantifying changes in the "high-frequency" relaxation dynamics of mixtures based on classical transition state theory, in conjunction with mathematical statements regarding the dependence of the entropy (S + ) and enthalpy (E + ) of activation of the high-frequency relaxation time on diluent mass fraction, x w . Specifically, we deduce a general classification scheme for diluents based on a consideration of the sign of the differential change in S + and E + with x w . Two of these classes of diluents exhibit a transition from plasticization to antiplasticization (defined specifically as a speeding up or slowing down of relaxation relative to the pure system, respectively) upon varying temperature through an "antiplasticization" temperature, T anti . Extensive dielectric relaxation measurements on polycarbonate (PC) as a function of temperature and diluent (Aroclor) concentration are utilized to illustrate our theoretical model, and we focus particularly on the Arrhenius " " dielectric relaxation process of these mixtures. Many aspects of our scheme for quantifying changes in the high-frequency dynamics of mixtures are rationalized by our mixture model. In particular, we show that the dilution of PC by Aroclor is consistent with a theoretically predicted (one of the two antiplasticization mixture classes mentioned above) transition from antiplasticization to plasticization with decreasing temperature. We briefly compare our findings from dielectric measurements with those from elastic incoherent neutron scattering and dynamical-mechanical measurements, providing further evidence for the antiplasticizationto-plasticization transition phenomena that we observe in our high-frequency dielectric measurements.