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Characterization of carrageenan by densitometry
Poledňáková, Halina ; Krouská, Jitka (referee) ; Hurčíková, Andrea (advisor)
The density of the carrageenan solution was investigated by densitometry depending on temperature and concentration. Subsequently, ultrasonic velocity was examined using densitometry and high-resolution ultrasonic spectroscopy. The measurements were executed using aqueous and sodium chloride solutions of carrageenan in a broad range of concentrations. It was found that the carrageenan samples are not liable to irreversible changes of density and ultrasonic velocity in dependence on temperature and concentration . Furthermore, it was proved that carrageenan in both mediums is stable, the samples do not exhibit degradation or changes in the properties of the ionic strength effect.
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The intrecations of dextran with surfactant SDS
Marčanová, Milada ; Kalina, Michal (referee) ; Hurčíková, Andrea (advisor)
Before the itself of characterization interactions of dextran with surfactant SDS, there were investigated properties of dextran solution in water and in sodium chloride. At first it was measured by densitometer, where their density and ultrasonic velocity was investigated, depending on concentration and temperature. The ultrasonic velocity was further measured by high resolution ultrasonic spectroscopy. Subsequently the interactions of dextran with surfactant SDS was examined to determine the critical aggregation and critical micelle concentration.
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Temperature dependence of carrageenan and hyaluronan solutions
Poledňáková, Halina ; Smilek, Jiří (referee) ; Hurčíková, Andrea (advisor)
This diploma thesis focuses on the study of temperature dependence of -carrageen, hyaluronan of low molecular weight (250–450 kDa) and hyaluronan of high molecular weight (1 500–1 750 kDa) in aqueous solutions. The description of temperature depending changes in properties of these substance is based on rheological method. This work concentrates on the characterization of viscoelasticity through measurement of the storage (elastic) and loss (viscous) modulus using -carrageen and hyaluronan solutions of different molecular weights and different concentrations depending on temperature (20–50 °C, alternatively, in carrageen, 20–80 °C). The temperature dependence was further measured using an uncommon technique called high resolution ultrasonic spectroscopy (HR-US) which measured relative velocity of selected concentrations of -carrageen and hyaluronan of high molecular weight depending on the temperature of heating and cooling (20–80 °C). The measurements of temperature dependence were carried out for varied oscillation frequencies of rheometer sensor/frequency of ultrasonic waves. Knowledge of temperature dependence of the investigated substances may be applied in drug chemistry, primarily with respect to degradation due to high temperatures. The measured data gives information about sol-gel temperature and gel-sol temperature of carrageen.
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The intrecations of dextran with surfactant SDS
Marčanová, Milada ; Kalina, Michal (referee) ; Hurčíková, Andrea (advisor)
Before the itself of characterization interactions of dextran with surfactant SDS, there were investigated properties of dextran solution in water and in sodium chloride. At first it was measured by densitometer, where their density and ultrasonic velocity was investigated, depending on concentration and temperature. The ultrasonic velocity was further measured by high resolution ultrasonic spectroscopy. Subsequently the interactions of dextran with surfactant SDS was examined to determine the critical aggregation and critical micelle concentration.
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Temperature dependence of carrageenan and hyaluronan solutions
Poledňáková, Halina ; Smilek, Jiří (referee) ; Hurčíková, Andrea (advisor)
This diploma thesis focuses on the study of temperature dependence of -carrageen, hyaluronan of low molecular weight (250–450 kDa) and hyaluronan of high molecular weight (1 500–1 750 kDa) in aqueous solutions. The description of temperature depending changes in properties of these substance is based on rheological method. This work concentrates on the characterization of viscoelasticity through measurement of the storage (elastic) and loss (viscous) modulus using -carrageen and hyaluronan solutions of different molecular weights and different concentrations depending on temperature (20–50 °C, alternatively, in carrageen, 20–80 °C). The temperature dependence was further measured using an uncommon technique called high resolution ultrasonic spectroscopy (HR-US) which measured relative velocity of selected concentrations of -carrageen and hyaluronan of high molecular weight depending on the temperature of heating and cooling (20–80 °C). The measurements of temperature dependence were carried out for varied oscillation frequencies of rheometer sensor/frequency of ultrasonic waves. Knowledge of temperature dependence of the investigated substances may be applied in drug chemistry, primarily with respect to degradation due to high temperatures. The measured data gives information about sol-gel temperature and gel-sol temperature of carrageen.
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|
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Characterization of carrageenan by densitometry
Poledňáková, Halina ; Krouská, Jitka (referee) ; Hurčíková, Andrea (advisor)
The density of the carrageenan solution was investigated by densitometry depending on temperature and concentration. Subsequently, ultrasonic velocity was examined using densitometry and high-resolution ultrasonic spectroscopy. The measurements were executed using aqueous and sodium chloride solutions of carrageenan in a broad range of concentrations. It was found that the carrageenan samples are not liable to irreversible changes of density and ultrasonic velocity in dependence on temperature and concentration . Furthermore, it was proved that carrageenan in both mediums is stable, the samples do not exhibit degradation or changes in the properties of the ionic strength effect.
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