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Surfactants and Thickeners are both additives used in fully-formulated waterborne coatings to provide colloidal stability, thickening, and other functionality. The behavior of each ingredient in a coating must be understood and controlled to maintain colloidal stability as well as balance other desired properties of the liquid coating and the dry paint film. In this work, quaternary systems of Water-Latex-Thickener-Surfactant were investigated to further the understanding of their behavior in coatings. The thickener used was a well characterized, hydrophobically-modified, ethoxylated urethane (HEUR) with two C18 terminal hydrophobes and 795 average repeat units of ethylene oxide as the hydrophilic spacer. Two latexes, a hydrophobic butyl acrylate/styrene and a hydrophilic butyl acrylate/methyl methacrylate, each containing a small amount of methacrylic acid monomer were used. Six different surfactants, three non-ionic and three-anionic, were used. By maintaining the concentrations of latex and HEUR thickener as constants and varying the surfactant concentration, effects of the surfactant loading on rheology were determined. As concentration of surfactant increases, a characteristic shear-thickening maximum associated with bridging of latex particles by the HEUR thickener was seen to shift to higher shear rates; surfactants at all concentrations studied, except SDS, lowered the viscosities within the low shear rate region. Dynamic viscoelastic measurements shed further light into the behavior of the mixtures. The results will be explained based on surfactant and latex surface polarities and the competitive adsorption between the v surfactant and HEUR hydrophobes, and other interactions between surfactants and thickeners.

The diploma thesis is focused on the study of interactions between hyaluronan of various molecular weights with CAE surfactant. This surfactant does not have the exact composition and there is not known their molecular weight. One of the main parameters needed to describe the interactions between surfactant and hyaluronan, there is the determination of critical micellar concentration. The value of critical micellar concentration of CAE is not known yet. All measurements were made for solutions in aqueous solution and 0.15 M NaCl. The determination of the molecular weight of this surfactant was performed by the technique SEC-MALS-dRI. High resolution ultrasonic spectroscopy was chosen to determine the critical micellar concentration and tensiometry was chosen as a complementary method. The interactions of CAE surfactant with polysaccharide of hyaluronan were showed by high resolution ultrasonic spectroscopy and densitometry. Compressibility was calculated from ultrasonic velocity and density.

The thesis is focused on physical hyaluronan gels. The object of study is the interaction of hyaluronan (HyA) with oppositely charged surfactants in physiologic solution (0.15 M NaCl), leading to the formation of gel. In the first part of work have been determined the solids´ contents (X) in gels and their supernatants in percentage and their correlation with molecular weight concentration of original HyA solution and the ratio of binding sites on hyaluronan chain and surfactant CTAB. To conclude, decrease in HyA concentration results in higher values of X and vice versa. On the other hand, increase in the value of X with increasing molecular weight of HyA is not so significant. Analogous conclusions have been made for supernatants and the amount of solids in gel. Drying process has been recorded by drying curves. Swelling process has been used for the characterization of gels. The percentage of water that can be absorbed by dried gel, was determined. The results are in agreement with the measurements of solids´ content in gels. In the next part, the correlation between rheological properties of gels and HyA concentration, HyA molecular weight and concentration of CTAB have been studied by the oscillation and flow tests. The samples with the highest molecular weight and concentration have the most viscoelastic character. The flow test confirmed the assumed pseudoplastic behavior of gels. A very interesting trend arose while comparing HyA concentrations and viscosity in stock solutions and gels. Whereas in stock solution viscosity (at low shear rate) is lower with increasing of HyA concentration, the situation was exactly the opposite in gels. The results are in agreement with frequency tests and observed character of gels.

Doctoral thesis is focused on the study, research and development of heat insulating moulded refractory materials. The replacement of shaped instead of unshaped refractories is recently and strongly industrially demanded and belongs to ongoing research topics. With the increasing demand of energy savings, the excellent insulation properties are essential. The insulating properties of castables are the result of targeted porosity formation. The porosity is coming from the controlled air intrusion into material resulted to foamed structure. The foaming process was achieved by mixing of separately prepared aqueous foam into raw castable slurry or by in situ foaming of intensively mixed castable slurry with the surfactant additive. Nevertheless, the study of foam behaviour and the influence of additives on binder hydration and setting processes (i.e. calciumaluminate cement) was substantial for successful preparation of the experimental samples. The two types of the experimental samples were prepared. The first one was based on mixing of kaolin slurry with pre-prepared aqueous foam, whereas the de-aglomeration ability of kaolin specie was utilized to water-particle film formation. In situ foaming of multicomponent system is the second one. The both processes brought some negative attributes, so the optimal properties of prepared castables were achieved by their combination.

This work deals with the use of inorganic nanofibers in refractory castables. The thesis describes some of the results of previously conducted research on nanofibers. Also description of nanofibres, production and distribution. The experimental part is focused on studying the interaction of Al2O3 and SiO2 nanofibres with aluminate cement. The main subject of investigation is a dispersion of nanofibers using a surfactant and ultrasonication.

This thesis summarizes the current knowledge of reinforcement of concrete with nanofibers and conducted research on the issue of the use of inorganic nanofibers in ultrahighperformance concrete. Up to now, most researches focuses on the reinforcement using carbon nanotubes and nanofibers and inorganic nanofibers remained in the background of interest. Due to their different chemical properties, is not only a question of their influence on the microstructure and mechanical properties of concrete, but also the preparation of nanofiber suspension which is not explored such as in the case of carbon nanotubes and nanofibres.

Using the classical molecular dynamics simulations, the interfacial partitioning of selected aromatic species, namely benzoic acid and neutral and zwitterionic form of L-phenylalanine, was studied in the three slab systems: a) aqueous organics solution, b) palmitic acid monolayer in tilted condensed phase at aqueous organics solution and c) palmitic acid monolayer in tilted condensed - 2D gas phase coexistence at aqueous organics solution. The surface activity and the tendency to aggregate in particular at the air- aqueous and palmitic acid-aqueous interface was confirmed for all of the investigated aromatic species. The results of the simulation performed for the system of palmitic acid monolayer at benzoic acid solution were compared with the literature results of a similar simulation that employed a different parametrization. The comparison showed that the behaviour of the aromatic species at the fatty acid monolayer-aqueous interface strongly depends on the force field. The structural properties of the palmitic acid Langmuir monolayers were evaluated by means of the chain tilt angle and the headgroup region dihedral angle distributions analysis depending on the surface film density and the adsorbed aromatic species. The simulations mimicking the isothermal compression of the mixed monolayer in the...

Extracellular histones have been implicated as a cause of tissue inflammatory injury in a variety of disorders including sepsis, lung and liver diseases. However, little is known about their interactions with neutrophils and how this might contribute to injury. We used human neutrophils isolated from healthy donors in this study, and we conducted functional and mechanistic studies of the effects of histone H4 on neutrophils in vitro. We found that histone H4 acts as a strong neutrophil activator, inducing cytokine release, hydrogen peroxide production, adhesion and degranulation. H4 had a distinctive profile as compared to other neutrophil agonists in that it caused a marked and sustained elevation of intracellular calcium, which resulted from permeabilization of the neutrophil plasma membrane. Prior studies showed that neutrophils predominate in the early response to influenza A virus (IAV) infection in the lung, that IAV induces formation of neutrophil extracellular traps (NETs), and IAV infection in vivo is worsened by release of free histones in the lung. Neutrophils predominate in the early response in the lung to IAV infection. We found that IAV-induced NETs contain histones. Of interest, we found that histone H4 binds to and aggregates IAV particles, inhibits IAV infectivity in vitro, and increases the uptake of IAV by neutrophils. On the other hand, histone H4 potentiated IAV-induced neutrophil responses, including hydrogen peroxide production and calcium flux. These findings may in part explain the injurious effect of histones during IAV infection in vivo. We found that C-reactive protein (CRP) and surfactant protein-D (SP-D) or its carbohydrate binding domain bound to histone H4. CRP markedly reduced all of the effects of histone H4 on IAV and/or neutrophils. We also found that SP-D or its isolated binding domain reduced neutrophil activation induced by histone H4 which may in part account for its ability to reduce lung inflammation. We hope these findings provide a better understanding of the pro-inflammatory effects of histones (in IAV or other types of injury) and how the body protects itself against histone-induced injury. We also hope our results will aid development of novel strategies to ameliorate tissue damage caused by histones.

Cellulose nanocomposites offer interesting potential in terms of improved properties and new functionalities compared with microcomposites. Preparation from colloidal suspensions is promising, since high reinforcement content is possible and a wide range of constituents can be used. In the first study, the challenge is to form a stable suspension of well-dispersed carbon nanotubes (CNT) and nanofibrillated cellulose (NFC) in water and to prepare commingled high CNT content nanopaper structures by filtration. Various surfactants were used to modify CNT. The NFC was stabilized by charged carboxylate groups. A nonylphenol phosphate ester surfactant, NPPE, worked well for CNT and provided a stable and well-dispersed water suspension of CNT and NFC. Field emission scanning electron microscopy (FE-SEM), porosimetry and atomic force microscopy (AFM) were used to characterize nanopaper structure, and tensile properties were measured as well as surface resistivity. The processing route is water based and it is possible to prepare thin coatings as well as thicker films with a combination of low surface resistivity, flexibility in bending and high strength and toughness in tension.  As inspired by organo-modified layered silicates, the objective of the second study is to develop an environmentally friendly procedure for the surface modification of cellulose nanocrystals, CNC, using quaternary ammonium salts via adsorption. In order to obtain higher surface charge density on CNC, a new route is developed for preparation of CNC with carboxylic acid groups. Quanternary ammonium cations bearing alkyl, phenyl, glycidyl, and diallyl groups are used to modify CNC to render their surface more hydrophobic. The structure and surface hydrophobicity of unmodified and modified CNC as well as their dispersibility in organic solvent are characterized by AFM, FE-SEM, Fourier-transformed infrared spectroscopy (FT-IR), X-Ray analysis (XDR) and contact angle measurement (CAM). Future work will focus on surface-modified nanocelluloses in composite materials, in order to learn more about surface treatment effects on nanocomposite properties. / Nanokompositer från cellulosa har potential att ge starkt förbättrade egenskaper och ny funktionalitet jämfört med mikrokompositer. De ger även möjlighet till komposittillverkning från kolloidala suspensioner där man kan uppnå hög halt av förstärkningsfasen. Det är också möjligt att välja från en bred flora av lösliga och dispergerbara materialkomponenter. I första studien är utmaningen att skapa en stabil och väldispergerad suspension av kolnanorör (CNT) och nanofibrillerad cellulosa (NFC) i vatten för att genom filtrering framställa nanopapper med interpenetrerande CNT och NFC nätverk. Olika ytaktiva ämnen användes för att modifiera CNT. NFC stabiliserades genom laddade karboxylgrupper på ytan. En nonylfenol fosfatester, NPPE, fungerade bra för CNT och resulterade i en stabil och väldispergerad vattensuspension av CNT och NFC. FE-SEM, densitometri och AFM användes för att karakterisera nanopapperstruktur. Mekaniska egenskaper och ytresistivitet mättes. Processen för framställning av CNT/NFC nanopapper är vattenbaserade och det är möjligt att framställa tunna ytbeläggningar likväl som tjockare filmer. Dessa strukturer har en kombination av låg resistivitet, flexibilitet i böjning liksom hög hållfasthet och seghet i dragbelastning.  Syftet med den andra studien är att utgå från organo-modifierade skiktade silikater (leror) för att utveckla en miljövänlig ytmodifieringsmetod för nanocellulosa. För att öka ytladdningstätheten på CNC (nanokristaller från cellulosa) utvecklas ett nytt sätt att skapa karboxylgrupper på ytan. Kvarternära ammoniumsalter med alkyl, fenyl, glycidyl och diallylgrupper används för att göra ytan på CNC mer hydrofob. Ytans struktur och hydrofoba karaktär, liksom dispersionsegenskaper i organiska lösningsmedel, karakteriseras med hjälp av AFM, FE-SEM, FT-IR, XDR och kontaktvinkelmätning. Fortsatt arbete kommer att fokusera på ytmodifierad cellulosa i kompositmaterial, för att utveckla förståelsen för effekter av ytmodifiering på nanokompositers egenskaper / <p>QC 20120302</p>