ABSTRACT THE EFFECTS OF COLOR CONCENTRATES ON THE RHEOLOGY OF TINT BASES Douglas James Herrick Waterborne coatings are formulated with a number of different ingredients; water, latex polymers, pigments, surfactants, dispersants, defoamers, biocides, coalescing aids, and rheology modifiers or thickeners. Rheology modifiers are necessary in order to improve the physical properties of the coating before, during, and after application to a substrate. There are two kinds of rheology modifiers used in waterborne coatings; associative thickeners and non-associative thickeners. Coatings formulated with associative thickeners are quite sensitive to coating variations; the slightest change in the formulation has profound effects on the rheology of the coating. The opposite is true for coatings formulated with non-associative thickeners, where the rheology of the coating is not affected by minor changes in the formulation. The rheological properties of coatings are most influenced by the latex, thickener, and surfactant components of the coating. Previous studies have shown that the most ideal balance of rheological properties come from using associative thickeners. However, when waterborne coatings with associative thickeners are tinted with colorants containing high levels of surfactants they exhibit a significant decrease in viscosity. This change in viscosity results in poor sag resistance, poor brush loading, and may also cause a reduction in tint strength of the coating. In this work, the effect of tinting paints with six different colorants on the viscosity of the paint was studied for four different paint formulations: a pastel base and a deeptone base formulated with hydroxyethylcellulose (HEC-type) non-associative thickeners, and a pastel base and a deeptone base formulated with hydrophobically-modified, ethoxylated polyurethane (HEUR-type) associative thickeners. Gloss values and tinting strengths were obtained in accordance with ASTM methods D523-08 and D4838-88. In addition, dynamic stress and frequency sweeps were taken in order to study the effect of colorant addition on the viscoelastic properties of each sample. Colorant addition had little to no effects on the viscosity of the bases formulated with HEC thickeners, while there was a dramatic decrease in viscosity upon colorant addition to the bases with HEUR thickeners. Similar results were observed in the viscoelastic property analysis: little to no effects on the elastic and viscous moduli was seen with the tinted coatings formulated with the non-associative thickeners, while both the elastic and viscous moduli decreased for the coatings formulated with associative thickeners. A few of the deeptone bases showed increased moduli upon tinting compared to the parent deeptone base. The addition of colorant resulted in a decrease in tinting strength and an increase in gloss for those samples with associative thickeners, while the opposite was found for those samples with non-associative thickeners.

Das Surfactant-Protein C (SP-C) moduliert die Rheologie der Liquor cerebrospinalis (CSF). Während des Alterns geht sein abnehmender Spiegel mit einer erhöhten Belastung durch Läsionen der weißen Substanz einher. Pulmonale SP-C-Zwischenprodukte, die die BRICHOS-Domäne enthalten, verhindern Proteinfehlfaltung in der Lunge. So könnten zerebrale SP-C-Zwischenprodukte der zerebralen β-Amyloidose, einem Kennzeichen der Alzheimer-Krankheit, entgegenwirken. Es fehlen jedoch Daten über die molekulare Neuroanatomie von SP-C und seine Veränderungen in Wildtyp- und triple-transgenen (3xTg) Mäusen, die wesentliche Elemente der AD-Neuropathologie aufweisen. In dieser Studie wurden daher SP-C-haltige Strukturen im Vorderhirn von Mäusen und ihre räumlichen Beziehungen zu vaskulären, glialen und neuronalen Komponenten der neurovaskulären Einheit untersucht. Durch Fluoreszenzmarkierung wurde neuronales SP-C in der medialen Habenula, dem Indusium griseum und dem Hippocampus nachgewiesen. Die Glia-Gegenfärbung zeigte Astrozyten im Corpus callosum, die SP-C und S100β gemeinsam exprimieren. Insbesondere waren perineuronale Netze mit SP-C im Nucleus reticularis thalami, im lateralen Hypothalamus und im retrosplenialen Kortex assoziiert. Im Hippocampus älterer 3xTg-Mäuse wurden neben AD-ähnlichen Läsionen vermehrt punktförmige Ablagerungen gefunden, die SP-C und Reelin enthielten, aber keine BRICHOS-Immunreaktivität aufwiesen. Wildtyp- und 3xTg-Mäuse zeigten eine altersabhängige Zunahme solcher Ablagerungen, die bei etwa 24 Monate alten 3xTg-Mäusen deutlich ausgeprägt war. Die SP-C-Konzentrationen in den intra- und extrazellulären Kompartimenten jeder Gruppe zeigten eine umgekehrte Korrelation zwischen SP-C und Reelin, wobei insbesondere bei 3xTg-Mäusen eine altersabhängige Abnahme von SP-C und eine Zunahme von Reelin zu beobachten war. Zusammenfassend lässt sich sagen, dass extrazelluläres SP-C als Modulator der glymphatischen Clearance und potenzieller Ligand von PNs während des Alterns bei 3xTg-Mäusen abnimmt.:Inhaltsverzeichnis 1. Einführung...........................................................................................................1 2. Grundlagen .........................................................................................................4 2.1 Alzheimersche Erkrankung ...............................................................................4 2.2 Glymphatisches System....................................................................................6 2.3 Surfactant-Protein C..........................................................................................8 3. Zielsetzung..........................................................................................................12 4. Material und Methoden .......................................................................................13 4.1 Versuchstiere ....................................................................................................13 4.2 Gewebeaufbereitung für die Histochemie .........................................................14 4.3 Immunhistochemische Färbungen ....................................................................14 4.4 SP-C, gliale und neurovaskuläre Marker............................................................15 4.5 Doppelfärbungen in Kombination mit der Cy2-Markierung von SP-C................16 4.6 Mikroskopie und Bildgebung ..............................................................................17 4.7 Semiquantifizierung der SP-C-Ablagerungen im Hippokampus ........................18 4.8 Biochemische Analyse des SP-C- und Reelin-Gehalts in Mäusehirnen.............19 4.9 Statistische Auswertung der ELISA-Ergebnisse.................................................20 5. Ergebnisse ...........................................................................................................22 5.1 Qualitative Analyse der SP-C-Verteilung im Vorderhirn von Mäusen.................22 5.2 Semiquantitative Auswertung hippokampaler SP-C-Ablagerungen ..................39 5.3 Quantitative Analyse des SP-C- und Reelin-Gehalts in Mäusehirnen...............41 6. Diskussion............................................................................................................52 6.1 Technische Betrachtungen.................................................................................52 6.2 SP-C bei Drainage und Amyloidogenese ..........................................................53 6.3 SP-C und gliale Marker .....................................................................................55 6.4 SP-C und perineuronale Netze .........................................................................56 7. Zusammenfassung der Arbeit .............................................................................58 8. Literaturverzeichnis..............................................................................................63 Erklärung über die eigenständige Abfassung der Arbeit..........................................80 Lebenslauf................................................................................................................81 Danksagung ............................................................................................................83

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Per- and polyfluorinated substances (PFASs) have become an urgent topic in the water treatment industry in recent years as a consequence of new scientific discoveries of the correlation between the ingestion of some PFASs and their toxicity in humans and other organisms. PFASs are synthetic compounds present in a variety of products. Due to their desirable physical and chemical properties, PFASs are found in everything from clothes and furniture to aqueous fire-fighting foams. These compounds have also been identified in food and drinking water. The flourine-carbon bond present in these chemicals are exceptionally strong. Hence PFASs are persistent in nature when leaked to the environment. Additionally, the mobility properties of PFASs in the soil leads to contamination of surface and groundwater, necessitating actions from drinking water treatment plants (DWTP).  Nanofiltration plants have shown to successfully reduce the PFASs content in contaminated waters. The accumulation of PFASs in the concentrate is a potent source of these compounds and requires treatment before leaving the DWTP. Foam fractionation (FF) is an aeration technique that utilizes the hydrophobic properties of the PFASs compounds, in which PFASs adsorbs to the interfaces of introduced rising air-bubbles. The foam forming at the surface is then extracted, reducing the contamination.  In this study, the efficacy of the FF system on a concentrate from a two-stage nanofiltration membrane was evaluated. Also, the ability of surfactants to enhance the PFAS reduction was explored. The study was conducted in two parts. The first part was executed in a laboratory scale environment where five surfactants were added to a batchwise FF system. A minimum dose was determined and four experimental runs were then executed for each surfactant: Zero surfactant, 1x minimum dose, 2x minimum dose and 5x minimum dose. The results were evaluated and the surfactant showing the greatest improvement of PFASs removal, in this study a cationic surfactant, was chosen for further investigations in the second part. A continuous pilot FF system was used in the second part, the inner diameter of the colon was 54 mm, the height of the water column was held at 1 m prior to the aeration, the contact time (CT) was 10 minutes and the air-flow rate was set to be 4 L/min in all runs. Four experimental runs were conducted with different doses of the cationic surfactant: Zero surfactant, 1x minimum dose, 2x minimum dose and 3x minimum dose. Each experiment was repeated three times. A total of 12 runs were performed.  The results showed a removal efficiency of > 99 % of long-chained PFASs in all conducted experimental runs. Without the addition of surfactant, the average removal efficiency of ∑ short-chained PFASs was 61 % whereas maximum removal (77 %) was obtained with the highest surfactant dose applied. The mean reduction of ∑PFASs was 90 % in the zero surfactant run and 94 % in the highest dose experiment. The main findings from the study were that: 1) FF is an efficient method for the removal of long-chained PFASs from concentrate 2) Surfactants can be added to increase the removal of short-chained PFASs, 3) Higher dosing of the surfactant positively correlated with the removal efficiency of ∑short-chained PFASs in the FF system, however the relationship was not linear. / Per- and polyfluorerade ämnen (PFAS) är ett högaktuellt forskningsområde inom dricksvattenproduktion. På senare år har ny forskning påvisat korrelationen mellan intag av vissa PFAS-ämnen och hälsoproblem hos både människor och djur. PFAS är syntetiskt framställda kemikalier som förekommer i flertalet av våra vardagliga produkter på grund av dess fördelaktiga fysiska- och kemiska egenskaper. PFAS används i allt från smink och möbler till brandskum men har också påträffats i dricksvatten och mat. Kol-fluor bindningen som förekommer i alla PFAS-ämnen tillhör den organiska kemins starkaste bindningar. Följaktligen bryts PFAS-ämnen ned extremt långsamt när de hamnar i naturen. PFAS förmåga att mobilisera sig i jorden leder till kontaminering av yt- och grundvatten vilket tvingar dricksvattenverk att vidta åtgärder.  Nanofiltration har visat sig vara en kraftfull metod för att rena vatten från PFAS. I koncentratet, det vill säga det vatten som inte renas genom membranen, ackumuleras PFAS vilket förutsätter en separat reningsprocess innan vattnet kan släppas ut i naturen. Skumfraktionering är en luftbaserad teknik som utnyttjar hydrofobiciteten i PFAS. PFAS-ämnen adsorberas till ytan hos de injicerade luftbubblorna och transporteras till vattenytan där det bildar ett skum. Uppsamling av skummet reduceras således kontamineringen.  I den här studien bedömdes effektiviteten av skumfraktionering på koncentratet från ett två- stegs nanofiltrationsmembran. Därutöver undersöktes effekterna av att tillföra surfaktanter till systemet för att optimera reduceringen. Studien genomfördes i två delar. Den första delen ufördes i en mindre skala där 5 olika surfaktanter adderades till en satsvis- skumfraktioneringsprocess. Initialt bestämdes en minimum dosering för alla surfaktanter. Totalt genomfördes 4 experiment: Ingen surfaktant, 1x minimum dosen, 2x minimum dosen, 5x minimum dosen. Den surfaktant som påvisade bäst effekt på reduceringen av PFAS, i detta fall en katjonisk surfaktant, användes sedan.  I den andra delen av arbetet användes en kontinuerlig skumfraktioneringsprocess. Den inre diametern på kolonnen var 54 mm, vattenkolumnen hölls konstant på 1 m innan luftningen, kontakttiden var 10 min och lufthastigheten var satt till 4 L/min. Totalt genomfördes 4 experiment: Ingen surfaktant, 1x minimum dosen, 2x minimum dosen, 3x minimum dosen. Varje experiment upprepades tre gånger.  Resultatet visade att > 99 % av ∑långkedjiga PFAS-ämnen reducerades i alla genomförda experiment. Den genomsnittliga reduktionen av ∑kortkedjiga PFAS-ämnen var 63 % i experimenten utan surfaktant, medan i experimenten med den högsta doseringen var reduktionen 77 %. Den genomsnittliga reduktionen av ∑11 PFAS var 94 % för den högsta doseringen medans den var 90 % i experimentet utan surfaktant. Studien visade att:  1) Skumfraktionering är en effektiv metod för att rena koncentrat från långkedjiga-PFAS 2) Surfaktanter kan fördelaktigen användas för att optimera reningen av kortkedjiga-PFAS ämnen. 3) Högre dosering av surfaktanter korrelerade med högre reduktion av ∑kortkedjiga PFAS i skumfraktioneringsprocessen, ökningen var dock inte linjär.

<p> Using a single bubble suspended in a liquid flow regime, the effects of velocity, bubble size, and surfactant levels on the gas transfer process across the bubble interface were investigated. Mass transfer data reported in the literature for non-circulating carbon dioxide bubbles was verified. A mathematical model predicting the mass transfer process for the single bubble system used in this study was formulated and this model provided a reasonable fit for experimental data obtained for the dissolution of a carbon dioxide bubble into an aqueous solution of a second sparingly soluble gas. The fate of a hypothetical air bubble in an aerator was briefly considered.</p> / Thesis / Master of Engineering (MEngr)

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