Iveta Papučová - Academia.edu (original) (raw)

Papers by Iveta Papučová

Journal of Thermal Analysis and Calorimetry, 2020

For utilization of TiO2 in advanced applications, TiO2 after thermal treatment has to be in cryst... more For utilization of TiO2 in advanced applications, TiO2 after thermal treatment has to be in crystalline phase of anatase, because it gives the desired (photocatalytic) properties to material. The work deals with the study of anatase crystallization in TiO2 xerogel (dried at 80 °C) which was prepared from sol in “titanium isopropoxide–isopropyl alcohol–nitric acid–distilled water” system. DTA/TG analysis at heating rates of 10 and 2 °C min−1 was used for study of processes which take place during the thermal treatment of xerogel. Besides assumed anatase crystallization, the processes connected with mass loss were observed, and therefore, the process of thermal treatment of xerogel was observed using high-temperature Raman spectroscopy and high-temperature X-ray diffraction. Based on the comparison of results of all analyses, it can be concluded that the anatase is formed from xerogel by sequent processes in the temperature range of 280–400 °C—the first process represents the decomposition of xerogel and subsequent formation of amorphous TiO2 and the second process represents the formation of crystalline anatase, respectively.

Ceramics - Silikaty, 2021

The paper deals with the treatment temperature influence of inorganic-organic films on their surf... more The paper deals with the treatment temperature influence of inorganic-organic films on their surface properties. Inorganic-organic films were prepared by sol-gel method in "tetraethoxysilane-triethoxy(octyl)silane-water-nitric acid-isopropyl alcohol" system, and they were treated at temperatures of 140, 160, 180, 200 and 220 °C. The atomic force microscopy and sessile drop technique were used for characterization of film surface. The morphology, rms-roughness, and surface wettability (hydrophobicity) were evaluated. Surface free energy and its polar and dispersion component were calculated by Owens-Wendt-Rabel-Kaelble (OWRK) method, using contact angles of water and diiodomethane. On the basis of results of all studied properties, the films can be divided into two groups. The first group is represented by films prepared at temperatures of 140, 160 and 180 °C because there is the evaporation of present solvents. The second group is represented by films prepared at temperatures of 200 and 220 °C because the degradation processes of inorganic-organic components are in progress in films.

MATEC Web of Conferences

The aim of given paper is to study selected polymers using dynamic mechanical analysis method (DM... more The aim of given paper is to study selected polymers using dynamic mechanical analysis method (DMA). DMA is one of the most useful techniques for the study of the viscoelastic behaviour of thermoplastic polymers. In relation to DMA, an oscillatory stress and strain is applied to the material at specific frequencies and temperatures and based on this mentioned fact hereinbefore, the resulting changes after the loading in the material are measured. This technique allows detecting the melting temperature and the glass transition temperature of the thermoplastic materials. Furthermore, some spectroscopy techniques, such as energy dispersive X-ray spectroscopy (EDX) and infrared spectroscopy (IR), were also used for the investigation of the thermoplastics. The thermoplastics used for examination, namely polyethylene, polystyrene, polypropylene and polyethylene terephthalate, were gained from the waste of the packaging.

Journal of Coatings Technology and Research, 2022

This work deals with utilization of nano building blocks (NBBs) approach for modification of prop... more This work deals with utilization of nano building blocks (NBBs) approach for modification of properties of nanocomposite inorganic–organic films. Using the NBBs approach and acid-catalyzed reactions of tetraethoxysilane and triethoxy(octyl)silane, different procedures were used for preparation of six sols. Besides three different ways of mixing of initial precursors, two temperatures with different reaction time were used. The films were prepared by dip-coating technique and treated at temperature of 170°C. The sols were characterized by method of dynamic light scattering. The surface of films was characterized by atomic force microscopy and sessile drop technique. The influence of sol preparation procedure and reaction conditions on particles size in sols as well as the properties of films surface, such as hydrophobicity, morphology and rms-roughness, was observed. The procedure of sol preparation markedly influences the surface morphology of prepared nanocomposite inorganic–organic films. The changes in the studied properties were mainly observed for films, which were deposited from sols prepared at boiling temperature of isopropyl alcohol.

Applied Clay Science, 2021

Abstract From the aspect of the modern approach, it is necessary to increase the intercalation ef... more Abstract From the aspect of the modern approach, it is necessary to increase the intercalation efficiency for the objective of widespread market application of kaolinite. The submitted article deals with the microwave-assisted modification of kaolinite (Kaol). Using potassium acetate (KAc) solution and dimethyl sulphoxide (DMSO), Kaol was treated chemically by a microwave radiation at different time intervals at a set constant temperature. Different techniques, such as X-ray diffraction patterns analysis (XRD), Fourier transformed infrared spectroscopy (FT-IR) spectroscopy, thermogravimetry/ differential scanning calorimetry (TG/DSC), and scanning electron microscopy (SEM) were used to characterize Kaol and modified kaolinite samples. The modification was observed after microwave radiation was applied for a short time (30 min). Finally, for the supplementation of the results, the model rubber compounds, filled with Kaol, modified Kaol-KAc and Kaol-DMSO samples in the amount of 10 phr (parts per hundred rubber), were prepared. The effect of modified kaolinite on the curing characteristics and mechanical properties in sulphur-cured natural rubber (NR) compounds was investigated. Partial substitution of carbon black with Kaol-DMSO led to the lower minimum torque and the acceleration of the crosslinking reaction. Moreover, the NR vulcanizates containing Kaol-DMSO showed higher tensile strength and hardness along with high maximum torque that are indicators of the reinforcing effect of the modified kaolinite.

IOP Conference Series: Materials Science and Engineering, 2020

The given introduced paper deals with determination of contamination, content of elements, change... more The given introduced paper deals with determination of contamination, content of elements, change of composition and stability against the oxidation of motor oils. This work is aimed at chaining the individual properties of engine oil in dependence on the use of oil in traffic. Results show, that properties of engine oils do not depend only on the time of use but they also depend on other factors, such as state of the vehicle, the way of driving the vehicle, and the condition of maitenance.

IOP Conference Series: Materials Science and Engineering, 2020

The paper deals with the surface modification of the glass substrates using diffuse coplanar surf... more The paper deals with the surface modification of the glass substrates using diffuse coplanar surface barrier discharge (DCSBD). The changes of surface properties after modification with plasma discharge were observed in time. During eight days, contact angles were measured by the method of sessile drop, using distilled water and diiodomethane as testing liquids. The surface free energy and its polar and dispersion component were calculated using Fowkes method. The morphology and rms-roughness of modificated substrates were evaluated, using atomic force microscopy. The effect of modification by plasma discharge on the observed surface properties is the most noticeable immediately after modification. After 3 days, the observed surface properties of the modified surface are comparable to the unmodified surface.

IOP Conference Series: Materials Science and Engineering, 2020

The work deals with the influence of water corrosion on the surface properties of inorganic-organ... more The work deals with the influence of water corrosion on the surface properties of inorganic-organic SiO2 films, which were prepared from the sols in “tetraethoxysilane-isopropyl alcohol-water-nitric acid-triethoxy(octyl)silane” system. The atomic force microscopy and sessile drop technique was used on the characterization of surface properties. The morphology, rms-roughness, adhesion force and stiffness of prepared films were evaluated. Surface free energy and its polar and dispersion component were calculated by Owens-Wendt method using contact angles of distilled water and diiodomethane. The influence of corrosion on all of the studied properties of films was significant in the case of films prepared from sol with molar ratio of x(H2O) : x(SiO2) = 2.

Procedia Engineering, 2016

Occurrence of corrosion layers on observed glass samples has been monitored by means of cyclic te... more Occurrence of corrosion layers on observed glass samples has been monitored by means of cyclic tests in distilled water. Occurred corrosion layers were characterized by their thickness and refractive index. Characteristics of corrosion layers were calculated from dependence of reflectance on wavelength in visible spectrum area for particular observed glass and corrosion times. Thickness of corrosion layers reached tens of nanometers. Refractive index of corrosion layer for all observed glass samples was lower than refractive index of original glass. Dependence of layer thickness on time was regarded as result of leaching kinetics for observed glass. Initial layer thickness growth is stabilized in the course of time for glass samples with ZrO2 content of 0.00 wt. % and 0.41 wt. %. There is considerable trend in layer thickness growth along with corrosion time for glass samples with ZrO2 content of 0.81 wt. %, 1.26 wt. % and 1.66 wt. %. From dependence of refractive index on time we have found out that refractive index of corrosion layers occurring on particular glass samples were changed. We have found difference in values of refractive index amongst particular glass samples and we have explained it via their different porosity.

Procedia Engineering, 2016

The sol-gel method was used for preparation of sols and the precursor sols were prepared from a m... more The sol-gel method was used for preparation of sols and the precursor sols were prepared from a mixture of titanium(IV) tetraisopropoxide, isopropanol, water, nitric acid and "small molecule" as stabilizing reagent. The acetylacetone and acetic acid were used as small molecules ("stabilizers"). Three TiO2 xerogels were studied by DTA-TG analysis in combination with the XRD analysis. The crystallization was determined by non-isothermal analysis. The values of activation energy of crystallization were calculated using Johnson-Mehl-Avrami model. For xerogel without "small molecules" and xerogel with acetic acid, the activation energy of anatase crystallization is E = (1.07 ± 0.02)•10 5 J.mol-1 and E = (0.78 ± 0.02)•10 5 J.mol-1 , respectively. According to Avrami coefficient M ~ 1 for both xerogels, the mechanism of crystallization is surface nucleation. There is no crystallization of anatase in xerogel with acetylacetone.

Journal of Sol-Gel Science and Technology, 2018

The presented study deals with relation between chemical composition of precursor sols and surfac... more The presented study deals with relation between chemical composition of precursor sols and surface free energy of inorganic-organic films. Inorganic-organic films were prepared from precursor sols in "tetraethoxysilane (TEOS)-triethoxy (octyl)silane (OTES)-distilled water-nitric acid-isopropyl alcohol" system. The fifteen sols were prepared, where the ratio of K = x(OTES)/(x(TEOS) + x(OTES)) varied from 0 to 0.5 and ratio of R = x(H 2 O)/(x(TEOS) + x(OTES)) varied from 2 to 6. The relationship between chemical composition and surface free energy of inorganic-organic films was quantified by model selection approach. Model, which describes the studied relationship in the best way, was selected on the basis of Akaike information criterion. Based on the analysis of selected (the best describing) model, it was found out that the surface free energy as well as its dispersion and polar component are dependent only on K ratio in observed range of K and R values. Form the physico-chemical aspect, the observed dependences of surface free energy, its dispersive and polar component on chemical composition of precursor sols are explained by the influence of octyl groups on the sequences of hydrolysis and condensation reactions leading to formation of particles in precursor sol. In addition, the arrangement of octyl groups is used for explanation of particles arrangement on film surface.

IOP Conference Series: Materials Science and Engineering, Apr 2, 2020

The work deals with the influence of TiO2 films corrosion in distilled water on the surface prope... more The work deals with the influence of TiO2 films corrosion in distilled water on the surface properties of TiO2 films. Films were prepared from the sol in “Ti(i-PrO)4 - IPA - H2O - HNO3” system by dip-coating technique. The surface properties of films were observed using atomic force microscopy and sessile drop method. The morphology and rms-roughness of prepared films were evaluated. On the basis of Fowkes method, the contact angles of films, using distilled water and diiodomethane, were used for determination of surface free energy and its polar and dispersion components. The given surface properties of TiO2 films were compared from the aspect of their preparation temperature (200, 300 and 400 °C) as well as corrosion in water. It was observed, that the film preparation temperature did not have noticeable influence on studied surface properties for non-corroded films. The influence of corrosion was observed only for films prepared at temperature of 300 °C and 400 °C. The corrosion in water influenced the morphology of film surface, increased the roughness, contact angle for water as well as the value of dispersion component of surface free energy.

Journal of Thermal Analysis and Calorimetry, 2020

For utilization of TiO2 in advanced applications, TiO2 after thermal treatment has to be in cryst... more For utilization of TiO2 in advanced applications, TiO2 after thermal treatment has to be in crystalline phase of anatase, because it gives the desired (photocatalytic) properties to material. The work deals with the study of anatase crystallization in TiO2 xerogel (dried at 80 °C) which was prepared from sol in “titanium isopropoxide–isopropyl alcohol–nitric acid–distilled water” system. DTA/TG analysis at heating rates of 10 and 2 °C min−1 was used for study of processes which take place during the thermal treatment of xerogel. Besides assumed anatase crystallization, the processes connected with mass loss were observed, and therefore, the process of thermal treatment of xerogel was observed using high-temperature Raman spectroscopy and high-temperature X-ray diffraction. Based on the comparison of results of all analyses, it can be concluded that the anatase is formed from xerogel by sequent processes in the temperature range of 280–400 °C—the first process represents the decomposition of xerogel and subsequent formation of amorphous TiO2 and the second process represents the formation of crystalline anatase, respectively.

Ceramics - Silikaty, 2021

The paper deals with the treatment temperature influence of inorganic-organic films on their surf... more The paper deals with the treatment temperature influence of inorganic-organic films on their surface properties. Inorganic-organic films were prepared by sol-gel method in "tetraethoxysilane-triethoxy(octyl)silane-water-nitric acid-isopropyl alcohol" system, and they were treated at temperatures of 140, 160, 180, 200 and 220 °C. The atomic force microscopy and sessile drop technique were used for characterization of film surface. The morphology, rms-roughness, and surface wettability (hydrophobicity) were evaluated. Surface free energy and its polar and dispersion component were calculated by Owens-Wendt-Rabel-Kaelble (OWRK) method, using contact angles of water and diiodomethane. On the basis of results of all studied properties, the films can be divided into two groups. The first group is represented by films prepared at temperatures of 140, 160 and 180 °C because there is the evaporation of present solvents. The second group is represented by films prepared at temperatures of 200 and 220 °C because the degradation processes of inorganic-organic components are in progress in films.

MATEC Web of Conferences

The aim of given paper is to study selected polymers using dynamic mechanical analysis method (DM... more The aim of given paper is to study selected polymers using dynamic mechanical analysis method (DMA). DMA is one of the most useful techniques for the study of the viscoelastic behaviour of thermoplastic polymers. In relation to DMA, an oscillatory stress and strain is applied to the material at specific frequencies and temperatures and based on this mentioned fact hereinbefore, the resulting changes after the loading in the material are measured. This technique allows detecting the melting temperature and the glass transition temperature of the thermoplastic materials. Furthermore, some spectroscopy techniques, such as energy dispersive X-ray spectroscopy (EDX) and infrared spectroscopy (IR), were also used for the investigation of the thermoplastics. The thermoplastics used for examination, namely polyethylene, polystyrene, polypropylene and polyethylene terephthalate, were gained from the waste of the packaging.

Journal of Coatings Technology and Research, 2022

This work deals with utilization of nano building blocks (NBBs) approach for modification of prop... more This work deals with utilization of nano building blocks (NBBs) approach for modification of properties of nanocomposite inorganic–organic films. Using the NBBs approach and acid-catalyzed reactions of tetraethoxysilane and triethoxy(octyl)silane, different procedures were used for preparation of six sols. Besides three different ways of mixing of initial precursors, two temperatures with different reaction time were used. The films were prepared by dip-coating technique and treated at temperature of 170°C. The sols were characterized by method of dynamic light scattering. The surface of films was characterized by atomic force microscopy and sessile drop technique. The influence of sol preparation procedure and reaction conditions on particles size in sols as well as the properties of films surface, such as hydrophobicity, morphology and rms-roughness, was observed. The procedure of sol preparation markedly influences the surface morphology of prepared nanocomposite inorganic–organic films. The changes in the studied properties were mainly observed for films, which were deposited from sols prepared at boiling temperature of isopropyl alcohol.

Applied Clay Science, 2021

Abstract From the aspect of the modern approach, it is necessary to increase the intercalation ef... more Abstract From the aspect of the modern approach, it is necessary to increase the intercalation efficiency for the objective of widespread market application of kaolinite. The submitted article deals with the microwave-assisted modification of kaolinite (Kaol). Using potassium acetate (KAc) solution and dimethyl sulphoxide (DMSO), Kaol was treated chemically by a microwave radiation at different time intervals at a set constant temperature. Different techniques, such as X-ray diffraction patterns analysis (XRD), Fourier transformed infrared spectroscopy (FT-IR) spectroscopy, thermogravimetry/ differential scanning calorimetry (TG/DSC), and scanning electron microscopy (SEM) were used to characterize Kaol and modified kaolinite samples. The modification was observed after microwave radiation was applied for a short time (30 min). Finally, for the supplementation of the results, the model rubber compounds, filled with Kaol, modified Kaol-KAc and Kaol-DMSO samples in the amount of 10 phr (parts per hundred rubber), were prepared. The effect of modified kaolinite on the curing characteristics and mechanical properties in sulphur-cured natural rubber (NR) compounds was investigated. Partial substitution of carbon black with Kaol-DMSO led to the lower minimum torque and the acceleration of the crosslinking reaction. Moreover, the NR vulcanizates containing Kaol-DMSO showed higher tensile strength and hardness along with high maximum torque that are indicators of the reinforcing effect of the modified kaolinite.

IOP Conference Series: Materials Science and Engineering, 2020

The given introduced paper deals with determination of contamination, content of elements, change... more The given introduced paper deals with determination of contamination, content of elements, change of composition and stability against the oxidation of motor oils. This work is aimed at chaining the individual properties of engine oil in dependence on the use of oil in traffic. Results show, that properties of engine oils do not depend only on the time of use but they also depend on other factors, such as state of the vehicle, the way of driving the vehicle, and the condition of maitenance.

IOP Conference Series: Materials Science and Engineering, 2020

The paper deals with the surface modification of the glass substrates using diffuse coplanar surf... more The paper deals with the surface modification of the glass substrates using diffuse coplanar surface barrier discharge (DCSBD). The changes of surface properties after modification with plasma discharge were observed in time. During eight days, contact angles were measured by the method of sessile drop, using distilled water and diiodomethane as testing liquids. The surface free energy and its polar and dispersion component were calculated using Fowkes method. The morphology and rms-roughness of modificated substrates were evaluated, using atomic force microscopy. The effect of modification by plasma discharge on the observed surface properties is the most noticeable immediately after modification. After 3 days, the observed surface properties of the modified surface are comparable to the unmodified surface.

IOP Conference Series: Materials Science and Engineering, 2020

The work deals with the influence of water corrosion on the surface properties of inorganic-organ... more The work deals with the influence of water corrosion on the surface properties of inorganic-organic SiO2 films, which were prepared from the sols in “tetraethoxysilane-isopropyl alcohol-water-nitric acid-triethoxy(octyl)silane” system. The atomic force microscopy and sessile drop technique was used on the characterization of surface properties. The morphology, rms-roughness, adhesion force and stiffness of prepared films were evaluated. Surface free energy and its polar and dispersion component were calculated by Owens-Wendt method using contact angles of distilled water and diiodomethane. The influence of corrosion on all of the studied properties of films was significant in the case of films prepared from sol with molar ratio of x(H2O) : x(SiO2) = 2.

Procedia Engineering, 2016

Occurrence of corrosion layers on observed glass samples has been monitored by means of cyclic te... more Occurrence of corrosion layers on observed glass samples has been monitored by means of cyclic tests in distilled water. Occurred corrosion layers were characterized by their thickness and refractive index. Characteristics of corrosion layers were calculated from dependence of reflectance on wavelength in visible spectrum area for particular observed glass and corrosion times. Thickness of corrosion layers reached tens of nanometers. Refractive index of corrosion layer for all observed glass samples was lower than refractive index of original glass. Dependence of layer thickness on time was regarded as result of leaching kinetics for observed glass. Initial layer thickness growth is stabilized in the course of time for glass samples with ZrO2 content of 0.00 wt. % and 0.41 wt. %. There is considerable trend in layer thickness growth along with corrosion time for glass samples with ZrO2 content of 0.81 wt. %, 1.26 wt. % and 1.66 wt. %. From dependence of refractive index on time we have found out that refractive index of corrosion layers occurring on particular glass samples were changed. We have found difference in values of refractive index amongst particular glass samples and we have explained it via their different porosity.

Procedia Engineering, 2016

The sol-gel method was used for preparation of sols and the precursor sols were prepared from a m... more The sol-gel method was used for preparation of sols and the precursor sols were prepared from a mixture of titanium(IV) tetraisopropoxide, isopropanol, water, nitric acid and "small molecule" as stabilizing reagent. The acetylacetone and acetic acid were used as small molecules ("stabilizers"). Three TiO2 xerogels were studied by DTA-TG analysis in combination with the XRD analysis. The crystallization was determined by non-isothermal analysis. The values of activation energy of crystallization were calculated using Johnson-Mehl-Avrami model. For xerogel without "small molecules" and xerogel with acetic acid, the activation energy of anatase crystallization is E = (1.07 ± 0.02)•10 5 J.mol-1 and E = (0.78 ± 0.02)•10 5 J.mol-1 , respectively. According to Avrami coefficient M ~ 1 for both xerogels, the mechanism of crystallization is surface nucleation. There is no crystallization of anatase in xerogel with acetylacetone.

Journal of Sol-Gel Science and Technology, 2018

The presented study deals with relation between chemical composition of precursor sols and surfac... more The presented study deals with relation between chemical composition of precursor sols and surface free energy of inorganic-organic films. Inorganic-organic films were prepared from precursor sols in "tetraethoxysilane (TEOS)-triethoxy (octyl)silane (OTES)-distilled water-nitric acid-isopropyl alcohol" system. The fifteen sols were prepared, where the ratio of K = x(OTES)/(x(TEOS) + x(OTES)) varied from 0 to 0.5 and ratio of R = x(H 2 O)/(x(TEOS) + x(OTES)) varied from 2 to 6. The relationship between chemical composition and surface free energy of inorganic-organic films was quantified by model selection approach. Model, which describes the studied relationship in the best way, was selected on the basis of Akaike information criterion. Based on the analysis of selected (the best describing) model, it was found out that the surface free energy as well as its dispersion and polar component are dependent only on K ratio in observed range of K and R values. Form the physico-chemical aspect, the observed dependences of surface free energy, its dispersive and polar component on chemical composition of precursor sols are explained by the influence of octyl groups on the sequences of hydrolysis and condensation reactions leading to formation of particles in precursor sol. In addition, the arrangement of octyl groups is used for explanation of particles arrangement on film surface.

IOP Conference Series: Materials Science and Engineering, Apr 2, 2020

The work deals with the influence of TiO2 films corrosion in distilled water on the surface prope... more The work deals with the influence of TiO2 films corrosion in distilled water on the surface properties of TiO2 films. Films were prepared from the sol in “Ti(i-PrO)4 - IPA - H2O - HNO3” system by dip-coating technique. The surface properties of films were observed using atomic force microscopy and sessile drop method. The morphology and rms-roughness of prepared films were evaluated. On the basis of Fowkes method, the contact angles of films, using distilled water and diiodomethane, were used for determination of surface free energy and its polar and dispersion components. The given surface properties of TiO2 films were compared from the aspect of their preparation temperature (200, 300 and 400 °C) as well as corrosion in water. It was observed, that the film preparation temperature did not have noticeable influence on studied surface properties for non-corroded films. The influence of corrosion was observed only for films prepared at temperature of 300 °C and 400 °C. The corrosion in water influenced the morphology of film surface, increased the roughness, contact angle for water as well as the value of dispersion component of surface free energy.