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The Study of Dynamic Behaviour and Interactions During the Temperature-Induced Phase Separation in Polymer Solutions
Kouřilová, Hana ; Hanyková, Lenka (advisor) ; Štěpánková, Helena (referee) ; Dušková - Smrčková, Miroslava (referee)
Title: The Study of Dynamic Behaviour and Interactions During the Tempera- ture-Induced Phase Separation in Polymer Solutions Author: Hana Kouřilová Department / Institute: Charles University in Prague, Faculty of Mathemat- ics and Physics, Department of Macromolecular Physics Supervisor of the doctoral thesis: doc. RNDr. Lenka Hanyková, Dr. Abstract: 1 H and 13 C high-resolution NMR spectroscopies were used for the phase separation investigation in three types of polymer solutions: i) poly(N -isopropylmethacrylamide)/D2O/ethanol with or without negatively charged comonomer sodium methacrylate, ii) random copolymers poly(N -isopro- pylmethacrylamide-co-acrylamide) in D2O, D2O/ethanol and D2O/acetone and iii) D2O solutions of polymer mixtures poly(N -isopropylmethacrylamide)/poly(N - vinylcaprolactam). For i) cononsolvency effect and influence of temperature on the phase separation was studied. Differences between mesoglobules formed as a consequence of cononsolvency effect and of temperature were found. While inside the cononsolvency-induced mesoglobules no bound ethanol molecules were detect- ed, in the mesoglobules formed by the effect of temperature ethanol molecules were present. The charge introduced into the polymer chains strenghtens polymer- solvent interactions. For ii) mesoglobules were found to be...
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The Study of Dynamic Behaviour and Interactions During the Temperature-Induced Phase Separation in Polymer Solutions
Kouřilová, Hana
Title: The Study of Dynamic Behaviour and Interactions During the Tempera- ture-Induced Phase Separation in Polymer Solutions Author: Hana Kouřilová Department / Institute: Charles University in Prague, Faculty of Mathemat- ics and Physics, Department of Macromolecular Physics Supervisor of the doctoral thesis: doc. RNDr. Lenka Hanyková, Dr. Abstract: 1 H and 13 C high-resolution NMR spectroscopies were used for the phase separation investigation in three types of polymer solutions: i) poly(N -isopropylmethacrylamide)/D2O/ethanol with or without negatively charged comonomer sodium methacrylate, ii) random copolymers poly(N -isopro- pylmethacrylamide-co-acrylamide) in D2O, D2O/ethanol and D2O/acetone and iii) D2O solutions of polymer mixtures poly(N -isopropylmethacrylamide)/poly(N - vinylcaprolactam). For i) cononsolvency effect and influence of temperature on the phase separation was studied. Differences between mesoglobules formed as a consequence of cononsolvency effect and of temperature were found. While inside the cononsolvency-induced mesoglobules no bound ethanol molecules were detect- ed, in the mesoglobules formed by the effect of temperature ethanol molecules were present. The charge introduced into the polymer chains strenghtens polymer- solvent interactions. For ii) mesoglobules were found to be...
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Temperature-sensitive hydrogels
Šestáková, Eliška ; Hanyková, Lenka (advisor) ; Kouřilová, Hana (referee)
Hydrogely jsou měkké látky složené z polymerních sítí nabotnalých ve vodě. Některé z nich při změně teploty reagují skokovou změnou objemu. Tento fázový přechod je označován jako kolaps a odpovídá konformační změně, při které polymerní řetězce přechází z konformace klubka do konformace globule. Vlastnostmi se hydrogely podobají živým tkáním (chrupavkám, šlachám a sval·m), nejen proto jsou perspektivními materiály ohledně aplikací v biotechnologiích a farmacii. Tato práce se zabývá studiem kolapsu v hydrogelech tvořenými jednoduchými a dvojitými sítěmi (speciální případ dvou interpenetrujících polymerních sítí). Připravené vzorky (PNIPAAm, PNNDEAAm, PAMPS, PAAm a odpovídající dvojité sítě s PAAm jako druhou složkou) byly zkoumány pomocí botnacích, DSC a NMR experiment·. Botnací experimenty prokázaly, že dvojité sítě vykazují větší míru nabotnání a také vyšší kritickou teplotu než příslušné sítě jednoduché. Pomocí NMR a DSC experiment· byla určena entalpie kolapsu. Bylo zjištěno, že na signálech NMR se podílí jen část polymerních jednotek teplotně citlivého hydrogelu kv·li velké hustotě sesí'ování. 1
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Studium teplotně citlivých porfyrinů a jejich supramolekulárních komplexů
Hrubovský, Martin ; Kouřilová, Hana (advisor) ; Srb, Pavel (referee)
Study of thermoresponsive porphyrins and their supramolecular complexes Abstract: We studied the water-soluble artificial compound meso-tetrakis{3,4,5-tris[2-(2-(2- methoxyethoxy)ethoxy)ethoxy]phenyl}porphyrin prepared at NIMS, Japan, using the high-resolution NMR spectroscopy experimental method. We observed its LCST-type phase separation and applied the Flory-Huggins theory of polymer solutions in order to find its phase diagram (binodal and spinodal curves of the phase separation) and we also obtained molar enthalpies, entropies and critical temperatures of its phase separation; from the Flory-Huggins theory we discovered that its molecules form dimers in aqueous solutions. We also studied its host-guest interactions with the S-camphorsulfonic acid; we learned that the porphyrin binds cations and the porphyrin dimers break down when dissolved cations are available for complexation. We observed no phase separation in chloroform. We obtained no proof of the existence of molecular stacks larger than dimers. 1
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Nuclear magnetic resonance study of local changes in DNA double-helix stability induced by cytosine methylation
Socha, Ondřej ; Římal, Václav (advisor) ; Kouřilová, Hana (referee)
Cytosine methylation in CpG dinucleotides plays an important role in regulation of gene expression and cell differentiation. The structure of DNA double-helix is only weakly affected by cytosine methylation in CpG containing oligonucleotides, but a significant change of the duplex stability is caused. In this thesis, the melting preoperties of two self-complementary oligonucleotides CAAC GTTG and CAAm5C GTTG are studied using nuclear magnetic resonance spectroscopy. We measured 1H spectra at temperature range (276-350)K. The equilibrium and kinetic parameters of chemical exchange between duplexes and single strands were obtained by fitting the spectral lineshapes. Methylation of cytosine in the central CpG dinucleotide increases the melting temperature of each base pair. Thus, a high degree of cooperativity during chemical exchange is observed in our samples. Powered by TCPDF (www.tcpdf.org)
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The Study of Dynamic Behaviour and Interactions During the Temperature-Induced Phase Separation in Polymer Solutions
Kouřilová, Hana
Title: The Study of Dynamic Behaviour and Interactions During the Tempera- ture-Induced Phase Separation in Polymer Solutions Author: Hana Kouřilová Department / Institute: Charles University in Prague, Faculty of Mathemat- ics and Physics, Department of Macromolecular Physics Supervisor of the doctoral thesis: doc. RNDr. Lenka Hanyková, Dr. Abstract: 1 H and 13 C high-resolution NMR spectroscopies were used for the phase separation investigation in three types of polymer solutions: i) poly(N -isopropylmethacrylamide)/D2O/ethanol with or without negatively charged comonomer sodium methacrylate, ii) random copolymers poly(N -isopro- pylmethacrylamide-co-acrylamide) in D2O, D2O/ethanol and D2O/acetone and iii) D2O solutions of polymer mixtures poly(N -isopropylmethacrylamide)/poly(N - vinylcaprolactam). For i) cononsolvency effect and influence of temperature on the phase separation was studied. Differences between mesoglobules formed as a consequence of cononsolvency effect and of temperature were found. While inside the cononsolvency-induced mesoglobules no bound ethanol molecules were detect- ed, in the mesoglobules formed by the effect of temperature ethanol molecules were present. The charge introduced into the polymer chains strenghtens polymer- solvent interactions. For ii) mesoglobules were found to be...
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The Study of Dynamic Behaviour and Interactions During the Temperature-Induced Phase Separation in Polymer Solutions
Kouřilová, Hana ; Hanyková, Lenka (advisor) ; Štěpánková, Helena (referee) ; Dušková - Smrčková, Miroslava (referee)
Title: The Study of Dynamic Behaviour and Interactions During the Tempera- ture-Induced Phase Separation in Polymer Solutions Author: Hana Kouřilová Department / Institute: Charles University in Prague, Faculty of Mathemat- ics and Physics, Department of Macromolecular Physics Supervisor of the doctoral thesis: doc. RNDr. Lenka Hanyková, Dr. Abstract: 1 H and 13 C high-resolution NMR spectroscopies were used for the phase separation investigation in three types of polymer solutions: i) poly(N -isopropylmethacrylamide)/D2O/ethanol with or without negatively charged comonomer sodium methacrylate, ii) random copolymers poly(N -isopro- pylmethacrylamide-co-acrylamide) in D2O, D2O/ethanol and D2O/acetone and iii) D2O solutions of polymer mixtures poly(N -isopropylmethacrylamide)/poly(N - vinylcaprolactam). For i) cononsolvency effect and influence of temperature on the phase separation was studied. Differences between mesoglobules formed as a consequence of cononsolvency effect and of temperature were found. While inside the cononsolvency-induced mesoglobules no bound ethanol molecules were detect- ed, in the mesoglobules formed by the effect of temperature ethanol molecules were present. The charge introduced into the polymer chains strenghtens polymer- solvent interactions. For ii) mesoglobules were found to be...
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