Miroslaw Chorazewski | University of Silesia in Katowice (original) (raw)

Uploads

Papers by Miroslaw Chorazewski

ACS Applied Materials & Interfaces

The Journal of Physical Chemistry C

Herein, we tested the validity of the thermodynamic scaling of two (α and δ) relaxation processes... more Herein, we tested the validity of the thermodynamic scaling of two (α and δ) relaxation processes observed in the isotropic and nematic phases of itraconazole, that is classified as a liquid crystal (LC). As illustrated, relaxation times of both processes obtained at various thermodynamic conditions can be successfully superposed over 1/TVγ with different scaling exponents, γ, satisfying the thermodynamic scaling law. However, it was found that γ parameters determined in the isotropic phase are higher than those estimated for respective relaxation processes in the nematic state [J. Chem. Phys. 2015, 142, 224507]. It seems that differences in the arrangements of molecules within LC phases significantly affect the effective intermolecular potential resulting in the variation of scaling exponent and disagreement between γ and γEOS (estimated from the equation of state). The observed behavior suggests that both variables depend not only on the intermolecular potential but also on the degree of molecular ordering.

Understanding the effect of liquid viscosity in nanoconfinement is of paramount importance from b... more Understanding the effect of liquid viscosity in nanoconfinement is of paramount importance from both the fundamental and practical points of view. In particular, unexpected dynamic phenomena are ubiquitous in a broad range of nanofluidic applications. In this work, we used state-of-the-art high-pressure (P,V,T) calorimetry for direct observation of pressure, volume, temperature, and thermal effects during controlled intrusion/extrusion of liquids in nanoporous materials. It was discovered that the liquid extrusion pressure and the accompanying thermal effects can be controlled by changing solely the liquid viscosity. Such knowledge allowed us to propose the {nanoporous material + nonwetting liquid} system as a self-recovering nanobumper and to clarify the parameters for its optimization. Experimental results were interpreted in terms of confined classical nucleation theory as the slowdown of bubble expansion in the nanopores because of the high liquid viscosity. The present results are of practical value ...

Journal of Chemical and Engineering Data, 2011

Industrial & Engineering Chemistry Research, 2015

ABSTRACT

Journal of Agricultural and Food Chemistry, 2015

A new method of determining antioxidant capacity based on a mathematical model is presented in th... more A new method of determining antioxidant capacity based on a mathematical model is presented in this paper. The model was fitted to 1000 data points of electron paramagnetic resonance (EPR) spectroscopy measurements of various food product samples such as tea, wine, juice, and herbs with Trolox equivalent antioxidant capacity (TEAC) values from 20 to 2000 μmol TE/100 mL. The proposed mathematical equation allows for a determination of TEAC of food products based on a single EPR spectroscopy measurement. The model was tested on the basis of 80 EPR spectroscopy measurements of herbs, tea, coffee, and juice samples. The proposed model works for both strong and weak antioxidants (TEAC values from 21 to 2347 μmol TE/100 mL). The determination coefficient between TEAC values obtained experimentally and TEAC values calculated with proposed mathematical equation was found to be R(2) = 0.98. Therefore, the proposed new method of TEAC determination based on a mathematical model is a good alternative to the standard EPR method due to its being fast, accurate, inexpensive, and simple to perform.

Archives of Acoustics, 2015

It is with great sadness that we inform our readers about the recent death of Professor Stefan Er... more It is with great sadness that we inform our readers about the recent death of Professor Stefan Ernst. Stefan Ernst was born in Piaśniki, Upper Silesia, on November 03, 1934, to parents of Polish-German descent. His primary education started during the war at a German-speaking school in Wirek and continued in Olesno, where he also got his secondary education. As chemistry studies were not yet available at the University ofWrocław in 1953, he started studying biology and switched to chemistry a year later. He received his master’s degree in chemistry in 1959, as one of the first graduates in that major. Then, he started his work on application of thermodynamics and molecular acoustics in investigation of liquid phases under the guidance of the Prof. Bogusława Jeżowska-Trzebiatowska. On 28 November 1967, he defended his PhD thesis entitled “Association-Dissociation Equilibria and the Structure of Uranyl Compounds in Organic Solvents” at the University of Wrocław. Professor Stefan Ernst...

Journal of Solution Chemistry, 2015

The speeds of sound in dibromomethane, bromochloromethane, and dichloromethane have been measured... more The speeds of sound in dibromomethane, bromochloromethane, and dichloromethane have been measured in the temperature range from 293.15 to 313.15 K and at pressures up to 100 MPa. Densities and isobaric heat capacities at atmospheric pressure have been also determined. Experimental results were used to calculate the densities and isobaric heat capacities as the function of temperature and pressure by means of a numerical integration technique. Moreover, experimental data at atmospheric pressure were then used to determine the SAFT-VR Mie molecular parameters for these liquids. The accuracy of the model has been then evaluated using a comparison of derived experimental high-pressure data with those predicted using SAFT. It was found that the model provide the possibility to predict also the isobaric heat capacity of all selected haloalkanes within an error up to 6%.

The Supplementary Information includes experimental isothermal data of the isobaric thermal expan... more The Supplementary Information includes experimental isothermal data of the isobaric thermal expansivities α p for 1,3-dichloropropane and 1,5-dichloropentane (details of the materials are given at the end of the document) measured by the scanning trasitiometry (Table 1) as well as values of the parameters (collected in Tables 2 and 3) for their fits (for which the reference state has been fixed at the melting temperature at ambient pressure (i.e., p 0 =0.1MPa, and respectively T 0 =174.15K and T 0 =201.15K) to the temperature-pressure functions

The Journal of Chemical Thermodynamics, 2005

The molar isobaric heat capacities for the binary mixtures (1-butanol + 1,3-butanediol) were dete... more The molar isobaric heat capacities for the binary mixtures (1-butanol + 1,3-butanediol) were determined in the temperature range from (285 to 353) K from measurements of isobaric specific heat capacity in a differential scanning calorimeter. The composition dependencies of the excess molar isobaric heat capacities obtained from the experimental results were fitted by the Redlich-Kister polynomials. Below the temperature 318.15 K, the excesses are positive and between the temperatures (323.15 and 348.15) K the excess curves are s-shaped. At the temperature 353.15 K, the excess is negative. In addition, the molar isochoric heat capacities at the temperature 298.15 K were estimated.

ACS Applied Materials & Interfaces

The Journal of Physical Chemistry C

Herein, we tested the validity of the thermodynamic scaling of two (α and δ) relaxation processes... more Herein, we tested the validity of the thermodynamic scaling of two (α and δ) relaxation processes observed in the isotropic and nematic phases of itraconazole, that is classified as a liquid crystal (LC). As illustrated, relaxation times of both processes obtained at various thermodynamic conditions can be successfully superposed over 1/TVγ with different scaling exponents, γ, satisfying the thermodynamic scaling law. However, it was found that γ parameters determined in the isotropic phase are higher than those estimated for respective relaxation processes in the nematic state [J. Chem. Phys. 2015, 142, 224507]. It seems that differences in the arrangements of molecules within LC phases significantly affect the effective intermolecular potential resulting in the variation of scaling exponent and disagreement between γ and γEOS (estimated from the equation of state). The observed behavior suggests that both variables depend not only on the intermolecular potential but also on the degree of molecular ordering.

Understanding the effect of liquid viscosity in nanoconfinement is of paramount importance from b... more Understanding the effect of liquid viscosity in nanoconfinement is of paramount importance from both the fundamental and practical points of view. In particular, unexpected dynamic phenomena are ubiquitous in a broad range of nanofluidic applications. In this work, we used state-of-the-art high-pressure (P,V,T) calorimetry for direct observation of pressure, volume, temperature, and thermal effects during controlled intrusion/extrusion of liquids in nanoporous materials. It was discovered that the liquid extrusion pressure and the accompanying thermal effects can be controlled by changing solely the liquid viscosity. Such knowledge allowed us to propose the {nanoporous material + nonwetting liquid} system as a self-recovering nanobumper and to clarify the parameters for its optimization. Experimental results were interpreted in terms of confined classical nucleation theory as the slowdown of bubble expansion in the nanopores because of the high liquid viscosity. The present results are of practical value ...

Journal of Chemical and Engineering Data, 2011

Industrial & Engineering Chemistry Research, 2015

ABSTRACT

Journal of Agricultural and Food Chemistry, 2015

A new method of determining antioxidant capacity based on a mathematical model is presented in th... more A new method of determining antioxidant capacity based on a mathematical model is presented in this paper. The model was fitted to 1000 data points of electron paramagnetic resonance (EPR) spectroscopy measurements of various food product samples such as tea, wine, juice, and herbs with Trolox equivalent antioxidant capacity (TEAC) values from 20 to 2000 μmol TE/100 mL. The proposed mathematical equation allows for a determination of TEAC of food products based on a single EPR spectroscopy measurement. The model was tested on the basis of 80 EPR spectroscopy measurements of herbs, tea, coffee, and juice samples. The proposed model works for both strong and weak antioxidants (TEAC values from 21 to 2347 μmol TE/100 mL). The determination coefficient between TEAC values obtained experimentally and TEAC values calculated with proposed mathematical equation was found to be R(2) = 0.98. Therefore, the proposed new method of TEAC determination based on a mathematical model is a good alternative to the standard EPR method due to its being fast, accurate, inexpensive, and simple to perform.

Archives of Acoustics, 2015

It is with great sadness that we inform our readers about the recent death of Professor Stefan Er... more It is with great sadness that we inform our readers about the recent death of Professor Stefan Ernst. Stefan Ernst was born in Piaśniki, Upper Silesia, on November 03, 1934, to parents of Polish-German descent. His primary education started during the war at a German-speaking school in Wirek and continued in Olesno, where he also got his secondary education. As chemistry studies were not yet available at the University ofWrocław in 1953, he started studying biology and switched to chemistry a year later. He received his master’s degree in chemistry in 1959, as one of the first graduates in that major. Then, he started his work on application of thermodynamics and molecular acoustics in investigation of liquid phases under the guidance of the Prof. Bogusława Jeżowska-Trzebiatowska. On 28 November 1967, he defended his PhD thesis entitled “Association-Dissociation Equilibria and the Structure of Uranyl Compounds in Organic Solvents” at the University of Wrocław. Professor Stefan Ernst...

Journal of Solution Chemistry, 2015

The speeds of sound in dibromomethane, bromochloromethane, and dichloromethane have been measured... more The speeds of sound in dibromomethane, bromochloromethane, and dichloromethane have been measured in the temperature range from 293.15 to 313.15 K and at pressures up to 100 MPa. Densities and isobaric heat capacities at atmospheric pressure have been also determined. Experimental results were used to calculate the densities and isobaric heat capacities as the function of temperature and pressure by means of a numerical integration technique. Moreover, experimental data at atmospheric pressure were then used to determine the SAFT-VR Mie molecular parameters for these liquids. The accuracy of the model has been then evaluated using a comparison of derived experimental high-pressure data with those predicted using SAFT. It was found that the model provide the possibility to predict also the isobaric heat capacity of all selected haloalkanes within an error up to 6%.

The Supplementary Information includes experimental isothermal data of the isobaric thermal expan... more The Supplementary Information includes experimental isothermal data of the isobaric thermal expansivities α p for 1,3-dichloropropane and 1,5-dichloropentane (details of the materials are given at the end of the document) measured by the scanning trasitiometry (Table 1) as well as values of the parameters (collected in Tables 2 and 3) for their fits (for which the reference state has been fixed at the melting temperature at ambient pressure (i.e., p 0 =0.1MPa, and respectively T 0 =174.15K and T 0 =201.15K) to the temperature-pressure functions

The Journal of Chemical Thermodynamics, 2005

The molar isobaric heat capacities for the binary mixtures (1-butanol + 1,3-butanediol) were dete... more The molar isobaric heat capacities for the binary mixtures (1-butanol + 1,3-butanediol) were determined in the temperature range from (285 to 353) K from measurements of isobaric specific heat capacity in a differential scanning calorimeter. The composition dependencies of the excess molar isobaric heat capacities obtained from the experimental results were fitted by the Redlich-Kister polynomials. Below the temperature 318.15 K, the excesses are positive and between the temperatures (323.15 and 348.15) K the excess curves are s-shaped. At the temperature 353.15 K, the excess is negative. In addition, the molar isochoric heat capacities at the temperature 298.15 K were estimated.