Předkládaná dizertační práce se zabývá využitím techniky vysoce rozlišovací ultrazvukové spektroskopie (HRUS) při analýze huminových látek, za účelem získání hlubšího vhledu do problematiky vztahu mezi jejich primárními charakteristikami (elementární složení a rozložení uhlíku ve funkčních skupinách) a agregačními vlastnostmi. V literární rešerši jsou shrnuty nejnovější poznatky z oblasti studia huminových látek a představeny základní principy HRUS. Dále jsou uvedeny základní informace z oblasti fraktální analýzy a její aplikace na data získaná pomocí různých metod při studiu huminových látek. První úkol experimentální části je zaměřen na výhodné využití HRUS pro výzkum huminových látek, zde reprezentovaných standardy Mezinárodní společnosti pro huminové látky (IHSS) a to sodnými solemi huminových a fulvinových kyselin. Fulvinové kyseliny v jejich protonované formě byly taktéž zkoumány a to z důvodu objasnění vlivu sodného kationu. Pro popis chování vzorků byla použita mocninná funkce, jejíž empirické parametry byly korelovány s primárními charakteristikami. Byla vytvořena metoda fraktální analýzy a následně byla aplikována na data získána ultrazvukovou spektroskopií. Data získaná pomocí ultrazvukové spektroskopie byla zpracována i alternativní metodou. Ta spočívala v globálním pohledu na závislost ultrazvukové rychlosti na koncentraci a využití lineární regrese. Druhým z cílů práce je získání informací o vlivu teploty na stabilitu agregátů HS (IHSS standardy). Byl zkoumán vliv teplotních gradientů na chování agregátů při čtyřech různých koncentracích. V třetí části práce pak byly zkoumány koncentrační závislosti u vzorků pocházejících především z lokalit příliš nezasažených lidskou činností. HRUS data byla proložena mocninnou funkcí a zkoumána pomocí fraktální analýzy. Takto získané parametry byly korelovány s primárními vlastnostmi. Ze znalosti hustoty při dané koncentraci mohly být stanoveny velikosti hydratačních obálek. Jak se v současné době ukazuje, informace o agregačním chování huminových biomolekul mohou být v budoucnu velmi důležité pro navrhování průmyslových aplikací huminových látek, zejména v zemědělství a v ochraně životního prostředí, ale také například v medicíně.

One of the most prominent measurable parameters of the development of phases and phase transformations in inorganic systems are undoubtedly the volume changes of silicate matrix. The study of volume changes is crucial in the terms of usable durability of final product. They represent shrinkage or expansion of the material and may lead to significant decrease of technological and ecological parameters and often to complete destruction of these materials. Most often the volume changes can be observed when cement is used as a binder and in concretes, mortars, artificial aggregates and other similar materials. There are many methods to detect, define and determine the volume changes qualitatively or quantitatively. The development of phases was investigated as a part of the dissertation thesis and hence the volume changes were observed under the conditions closest to the real state in the construction industry. The raw materials and admixtures were selected which model the content of hazardous components present in conventional materials (both natural and secondary), used in construction and the relationship with volume changes was searched and demonstrated. The contacts for measuring the volume changes were attached to test surfaces of specimens and the physical - mechanical tests (volume changes, phase changes, strength, etc.), chemical analysis and ecotoxicity tests depending on the length of hydration were performed.

The deprotonation characteristics of fluorescent probes -naphthol and 8-hydroxypyrene-1,3,6-trisulphonic acid (HPTS) were studied in this diploma thesis, using steady-state and time-resolved fluorescence spectroscopy. Two cationic surfactants, Septonex and cetyltrimethylammonium bromide (CTAB), were studied. These surfactants were measured in the complex with hyaluronan (1.75 MDa, 1 MDa and 300 kDa). Steady-state fluorescence was used for determination of critical aggregation concentration of each surfactant and pKa*. Time-resolved fluorescence decays were used to calculate the average lifetimes and the deprotonation constants of naphthol and HPTS. The measurement with hyaluronan were compared with the polystyrenesulfonate (PSS) – surfactant system. The effect of hydration shell of hyaluronan on hyaluronan – surfactant complex formation results from the comparison of above mentioned systems. Large differences were found in the deprotonation characteristic between surfactants and even between individual molecular weights of hyaluronan. The measurement shows that the hydration shell is located near to the dissociated carboxyl groups of hyaluronan chain, where the interaction with the positively charged surfactants occurs. Furthermore, the aggregation number of Septonex was determined by quenching of pyrene using cetylpyridinium chloride (CPC) as a quencher. The aggregation number for 20 mM Septonex solution was determined as a value of 104 molecules. CPC was used for confirmation of the localization of -naphthol in the micelles of CTAB and polymer – CTAB, respectively.

Synthèse et hydratation de la phase ye’elimite Les ciments riches en ye’elimite ou les ciments sulfoalumineux (CSA) sont commercialisés pour la préparation des bétons à compensation de retrait. De plus, les ciments CSA présentent des caractéristiques écologiques associées à leur production, notamment une réduction de l'empreinte CO2. Le comportement expansif des ciments CSA est principalement contrôlé par la quantité de la phase ettringite, cette dernière est produite lors de l’hydratation de la phase importante, la ye’elimite [Ca4 (Al6O12)SO4]. Cette thèse présente, d’une part, les conditions optimales pour la synthèse de la phase ye’elimite la plus pure possible par des réactions à l’état solide, et d’autre part, une description fondamentale des mécanismes de formation de cette phase. Un autre aspect de ce travail vise à étudier l’influence de la finesse et de l’addition d’acide citrique sur la dissolution de la phase ye’elimite. Pour l’étude de l’effet de la finesse, une poudre fine et pure de ye’elimite a été synthétisée par des méthodes sol-gel, ces dernières méthodes de synthèse ont été développées d’une manière originale dans notre thèse. Plusieurs techniques expérimentales ont été réalisées pour mener à bien les différents aspects de la présente thèse, à savoir l'analyse quantitative par DRX (méthode Rietveld), l’analyse thermique (ATG, ATD, et dilatométrie), MEB (imagerie en rétrodiffusé et cartographie EDS), l’analyse BET, l’analyse granulométrique par diffraction laser, et l’analyse d'images (porosité 2D et analyse granulométrique 2D). / A Synthesis and hydration of ye’elimite Ye’elimite-rich cements or calcium sulfoaluminate (CSA) cements are commercialized to prepare shrinkage compensation and self-stressing concretes. Moreover, CSA cements show environmentally friendly characteristics associated to their production, which include reduced CO2 footprint. The expansive behavior of CSA cements is mainly controlled by ettringite amount, produced upon hydration of the key-phase, ye’elimite [Ca4(Al6O12)SO4]. This work presents, on one hand, the optimal conditions for the synthesis highly pure ye’elimite by solid state reactions, and on the other hand, it shows a fundamental description of ye’elimite formation mechanisms. Another aspect of the study encompasses the influence of fineness and citric acid addition on ye’elimite phase dissolution, then on hydrates composition of lab made ye’elimite-rich cement. For the fineness effect study, a highly fine and pure ye’elimite was originally synthetized by sol-gel methods. Various experimental techniques were performed to conduct the different aspects of the present study, namely XRD-Quantitative Rietveld analysis, Thermal analysis (TGA, DTG, DTA and Dilatometry), SEM (BSE imaging and EDS mapping), BET analysis, PSD by laser diffraction, and Image analysis (2D porosity and 2D PSD).

Cancer is responsible for upward of 13% of human deaths. Contemporary chemotherapy of disseminated cancer is often thwarted by dose limiting systemic toxicity and by multi-drug resistance (MDR). Riminophenazines are a novel class of potential anticancer agents that possess a potent multi-mechanistic antineoplastic action. Apart from their broad action against intrinsic, non-classical resistance, Riminophenazines inhibit the action of Pgp and hypothetically all ABC transporters demonstrating their great utility against classical MDR. Considering that combination chemotherapy is the norm, the vision directing R&D efforts was that Riminophenazines could be used with benefit within many standard chemotherapeutic regimes. The strategic intent of this project was to attain improved therapeutic benefit for patients through gains in both pharmaco dynamic and pharmacokinetic specificity for cancer cells over what is currently available. Tactically, this was driven through the use of synergistic Fixed-Ratio Drug Combinations (FRDC) encapsulated within tumour-targeting Nanoparticulate Drug Delivery Systems (NDDS). Long-term aims of this R&D project were to: 1) Screen FRDC of clofazimine (B663) and the lead derivative (B4125) with etoposide, paclitaxel and vinblastine for synergistic drug interactions in vitro. 2) Design, assemble and characterize a novel nanoparticulate, synergistic, anticancer co-formulation. 3) Evaluate the in vivo safety and efficacy of the developed product/s in accordance with international regulatory guidelines. Using the median effect and combination index equations, impressive in vitro synergistic drug interactions (CI<1) were shown for various FRDC of the three standard chemotherapeutics tested (etoposide, paclitaxel and vinblastine) in combination with either B663 or B4125 against MDR neoplastic cell cultures. Considering in vitro results and with the view to advance quickly to clinical studies, the already approved clofazimine (B663) was elected as the combination partner for paclitaxel (PTX). Considering the potency and wide action of PTX, a novel coformulation (designed to circumvent drug resistance) has the potential to greatly impact upon virtually all cancer types, particularly if selectively delivered through innovative delivery systems and loco-regional administration. A passively tumour targeting, micellular NDDS system called Riminocelles™ that encapsulates a synergistic FRDC of B663 and PTX has been designed, assembled using thin film hydration methods and characterized in terms of drug loading, particle size, zeta potential, CMC and drug retention under sink conditions. An acute toxicity and a GLP repeat dose toxicity study confirmed Riminocelles to be well tolerated and safe at clinically relevant dosages whilst Taxol® (QDx7) produced statistically significant (P<0.05) weight loss within 14 days. The same study demonstrated statistically significant (P<0.05) tumour growth delays superior to that of Taxol at an equivalent PTX dosage of 10 mg/kg. Importantly, all components (amphiphiles and drugs) used in assembly of Riminocelles are already individually approved for medicinal use - this promotes accelerated development towards advanced clinical trials and successful registration. Although these results are very promising (outperforming Taxol), this system was however found in a pharmacokinetic study to suffer from in vivo thermodynamic instability due to the high concentration (abundance) of albumin present in plasma. For this reason, in vivo longevity within circulation, permitting passive tumour accumulation was not fully realized. A second NDDS called the RiminoPLUS™ imaging system was additionally developed. This lipopolymeric nanoemulsion system has successfully entrapped Lipiodol® Ultra fluid (an oil based contrast agent) within the hydrophobic core of a monodisperse particle population with a size of roughly 100 nm and a stability of one week. This formulation is therefore thought capable of CT imaging of tumour tissue and drug targeting after either intravenous or loco-regional injection. In vivo proof of the imaging concept is warranted. The results of this study serve to highlight the great potential of in vitro optimized synergistic FRDC against drug resistant cancers. Lipopolymeric micelles are an effective way to formulate multiple hydrophobic drugs for intravenous administration and present a means by which cancer can be readily targeted; provided that the delivery system possess the prerequisite in vivo stability and surface attributes. Further experiments exploring synergistic drug and biological combinations as well as “intelligent” NDDS actively guided through specific molecular recognition are called for. / Thesis (PhD)--University of Pretoria, 2012. / Pharmacology / unrestricted

This dissertation aims to provide a comprehensive understanding of the evolution of solid phase composition with ongoing hydration in OPC‒rich and CAC‒CsHx rich ternary binders. The work is based on a multi‒method approach including XRD, TGA, MAS NMR spectroscopy, calorimetry, microscopy and thermodynamic calculations. From the combinations of results obtained from the different analytical methods, a schematic representation of the phase evolution with ongoing hydration in OPC and CAC‒CsHx rich combinations was achieved, along with plots showing the distributing hydrate phases in the ternary diagram OPC‒CAC‒CsHx. C‒S‒H, portlandite, ettringite and AFm phases stand as main hydration products in the OPC‒rich combinations. C‒S‒H accounts for ~70% of the X‒ray amorphous fraction. In the CAC‒CsHx rich combinations ettringite along with AH3, monosulphoaluminate, strätlingite and hydrogranet phases precipitate. The high portions of X‒ray amorphous fractions in such combinations were mainly attributed to AH3 gel and AFm phases. Additionally, comparison of QXRD results with stoichiometric calculations, thermal analysis and 27Al NMR revealed that a portion of the formed ettringite and portlandite are in an X‒ray amorphous state during hydration. The variation of CAC type and water content strongly influences the hydration mechanism and phase assemblage in the ternary binders, whereas differences in mixtures with different sulphate sources are mainly related to the different dissolution kinetics of the sulphate.

Numerous recurrent situations following mixing and pumping of mortars and concretes cause degradation of fluidity and hardening characteristics. Which, in turn, lead to adverse effects on the quality of workmanship and structural defects. Nonetheless, relatively little research on the mixing and pumping energies used for the onsite transport and preparation of mortar or concrete has been directed at the core reasons or mechanisms for changes in technological properties. This dissertation describes and explains the effects of various mixing and pumping parameters on the mortar characteristics in a field trial and on a laboratory scale. Observations using a rheograph revealed that shearing action does exhibit the most pronounced influence on the characteristics of mortars during the pumping. The performed investigations indicate that higher shearing actions, for example, excessive mixing duration and long-distance pumping lead to reduced flowability, accelerated and increased hydration rate, increased early compressive strength and early-age shrinkage. From these findings, the underlying mechanism responsible for acceleration and increase of hydration rate is pinpointed as: the increased dissolution from the active surface area due to the destruction of the protective superficial layers of cement grains, as well as a transition from flocculation to dispersion. The creation of new surfaces leads to further consumption of active super plasticizer in solution phase and to subsequent degrading changes in fluidity (decreasing flowability). The degradation of fluidity and densification of microstructure provoked by the hydration changes do increase the early age shrinkage of mortar.

Die Adsorption von Additiven an den Oberflächen eines Kristallisates wird als eine hauptsächliche Ursache für die Beeinflussung von Kristallwachstum und Morphologie angesehen und spielt bei vielen Kristallisationsprozessen eine entscheidende Rolle. Gerade für die Calciumsulfate, die im Millionen-Tonnen-Maßstab jährlich in Deutschland verarbeitet werden, stellt der Additiv-Einsatz einen Hauptkostenfaktor dar, während gleichzeitig die Additivwirkung mechanistisch nicht ausreichend gut verstanden und damit derzeit nicht vorhersagbar ist. Zur Erlangung eines besseren Verständnisses wurden mit Hilfe von molekulardynamischen Computersimulationen die Prozesse in den Grenzflächen zwischen festen Calciumsulfaten und wässriger Additivlösung auf atomarer Ebene analysiert. Wesentlicher Untersuchungsschwerpunkt war dabei die Rolle des polaren Lösungsmittels Wasser auf die Wechselwirkung zwischen verschiedenen ionischen Additivspezies und den Salzkristallen.:1. Einleitung und Zielsetzung 1 2. Literatur 6 2.1. Kristallstrukturen der Calciumsulfate 7 2.2. Kristallmorphologie und relevante Kristallflächen 10 2.2.1. Kristallwachstum und Morphologie der Calciumsulfate 10 2.2.2. Theoretische Methoden zur Morphologievorhersage 13 2.2.3. Morphologievorhersage für die Calciumsulfate 18 2.3. Struktur von Mineral-Wasser-Grenzflächen 20 2.3.1. Experimentelle Untersuchungen 20 2.3.2. Simulationen 25 2.4. Morphologiebeeinflussung der Calciumsulfate durch Additive 26 2.4.1. Additive für Calciumsulfate und deren Wirkungsweise 26 2.4.2. Beeinflussung der Gipsmorphologie durch Zitronensäure und Aminosäuren 28 2.5. Stand der Technik von Adsorptionssimulationen 31 2.5.1. Methodenüberblick 31 2.5.2. Molekulardynamische Adsorptionssimulationen 33 2.5.3. Modellierungen und Simulationen der Calciumsulfat-Additiv- Wechselwirkung 44 3. Methodik 47 3.1. Simulationsbasis 49 3.1.1. Randbedingungen und Annahmen 49 3.1.2. Simulationsmethoden und -parameter 51 3.1.3. Kraftfeld 55 3.1.4. Erstellen von Simulationsboxen 60 3.2. Simulationen zur Morphologievorhersage 65 3.2.1. Durchgeführte Simulationen 66 iiiInhaltsverzeichnis 3.2.2. Berechnung der Morphologie im Vakuum 68 3.2.3. Berechnung der Morphologie in Lösung 69 3.2.4. Zusammenfassung 72 3.3. Simulationen der CaSO 4 -Wasser-Grenzfläche 74 3.3.1. Durchgeführte Simulationen 74 3.3.2. Charakterisierung der Oberflächenstabilität 75 3.3.3. Strukturelle Charakterisierung der Hydratationsschichten 77 3.3.4. Kinetische Charakterisierung der Hydratationsschichten 82 3.3.5. Thermodynamische Charakterisierung der Hydratations- schichten 83 3.3.6. Zusammenfassung 87 3.4. Simulation der Adsorption 89 3.4.1. Durchgeführte Simulationen 89 3.4.2. Berechnung der Adsorptionsenergie 103 3.4.3. Berechnung der Freien Adsorptionsenergie 106 3.4.4. Zusammenfassung 112 4. Ergebnisse und Diskussion 114 4.1. Morphologievorhersage und Flächenauswahl 115 4.1.1. Die Morphologie im Vakuum 115 4.1.2. Die Morphologie in Lösung 123 4.1.3. Flächenauswahl 126 4.2. Die Mineral-Wasser-Grenzfläche 127 4.2.1. Oberflächenstabilität 127 4.2.2. Strukturelle Charakterisierung der Hydratationsschichten 133 4.2.3. Kinetische Charakterisierung der Hydratationsschichten 153 4.2.4. Thermodynamische Charakterisierung der Hydratations- schichten 162 4.2.5. Einfluss der Simulationsmethodik 166 4.3. Die Adsorption 167 4.3.1. Einfluss des Lösungsmittels 167 4.3.2. Einfluss des Additivs 176 4.3.3. Einfluss der Fläche 186 4.3.4. Einfluss der Simulationsmethodik 201 5. Zusammenfassung und Ausblick 211 ivInhaltsverzeichnis Abkürzungsverzeichnis V-1 Literaturverzeichnis V-6 Abbildungsverzeichnis V-34 Tabellenverzeichnis V-38 A. Methoden A-1 A.1. Erstellen von Simulationsboxen mit Kristallschichten A-2 A.1.1. Randbedingungen A-2 A.1.2. Erstellen der Elementarzelle A-3 A.1.3. Erstellen der Oberflächenelementarzelle A-3 A.2. Voruntersuchungen zur Adsorption A-8 A.2.1. Ausgangssituation A-8 A.2.2. Finden energetisch günstiger Konformationen A-11 A.2.3. Berechnung der Freien Adsorptionsenergie A-13 A.2.4. Berechnung der Adsorptionsenergie A-23 A.3. Clusteranalyse A-24 B. Tabellen B-1 C. Abbildungen C-1

Mit zunehmendem Alter zeigt das Verbundverhalten von Multifilamentgarnen aus alkaliresistentem Glas (AR-Glas) oder Kohlenstoff in Abhängigkeit von der Zusammensetzung der zementgebundenen Matrix eine sehr unterschiedliche Entwicklung. Während bei AR-Glas teilweise drastische Verluste des Leistungsvermögens zu verzeichnen sind, treten diese bei Kohlefasern nicht auf. Zur Untersuchung der Phänomene wurden beidseitige Garnauszugversuche durchgeführt und die Interphase zwischen Filamenten und Matrix im Rasterelektronenmikroskop (ESEM) untersucht. Die unterschiedlichen mechanischen Eigenschaften stehen in Zusammenhang mit verschieden ausgeprägten Mikrostrukturen der Interphasen. Welche Ursachen die unterschiedliche morphologische Entwicklung der Interphasen hat, ist Gegenstand aktueller Arbeiten.

Raman multivariate curve resolution (Raman-MCR) spectroscopy is used to study water-mediated interactions by decomposing Raman spectra of aqueous solutions into bulk water and solute-correlated (SC) spectral components. The SC spectra are minimum-area difference spectra that reveal solute-induced perturbations of water structure, including changes in water hydrogen-bonding strength, tetrahedral structure, and formation of dangling (non-hydrogen-bonded) OH defects in a solute's hydration shell. Additionally, Raman-active intramolecular vibrational modes of the solute may be used to uncover complementary information regarding solute--solute interactions. Herein, Raman-MCR is applied to address fundamental questions related to: (1) confined cavity water and its connection to host-guest binding, (2) hydrophobic hydration of fluorinated solutes, (3) specific ion effects on nonionic micelle formation, and (4) ion pairing in aqueous solutions.