| 1. |
- Bergenståhl, B, et al.
(författare)
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Adsorption structures in food emulsions
- 1992
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Ingår i: Emulsions. - : Kluwer Academic Publishers. ; , s. 51-60
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Bokkapitel (refereegranskat)abstract
- Food emulsions in particular, but also most other technical emulsions, are complex mixtures. When surface active components adsorb from a solution of several different surface active molecules, the formed adsorbed layer can roughly be classified in three different structures, i) A monolayer containing one predominant molecule, ii) The formation of one adsorbed monolayer containing a mixture of molecules, iii)Adsorption in layers. A model of an ice cream emulsion is an example in which a layered surface structure is formed. Four different methods were applied to investigate the surface: measurements of the interfacial tension, flocculation rate measurements, electrophoretic mobility measurements and TIRF (Total Internal Reflection Fluorescence). The conclusion we made from this investigation was that the adsorption from solutions with several surface active components might lead to the formation of complex layered structures.
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| 2. |
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| 3. |
- Bergenståhl, B, et al.
(författare)
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Surface forces in emulsions
- 1990. - 2
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Ingår i: Food Emulsions. - : Marcel Dekker. ; , s. 41-96
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Bokkapitel (refereegranskat)
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| 4. |
- Bergström, L
(författare)
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Characterization of the surface chemistry of silicon nitride powders
- 1994
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Ingår i: Ceramic Transactions. - : American Ceramic Society. ; , s. 77-87
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Bokkapitel (refereegranskat)abstract
- Introduction: Silicon nitride is a ceramic material with a potential for high strength at room as well as elevated temperatures, good thermal shock resistance and relatively good oxidation resistance. However, optimal properties can only be realized when the microstructure and the grain boundary composition of the sintered body is controlled. Several studies have shown that the surface properties of the starting powder, together with the choice and addition of sintering aids, play a decisive role in determining the final properties [1-3]. However, the final properties of the sintered material depend on many different parameters. These parameters include the green-body characteristics, the physical and bulk chemical powder properties and the sintering conditions together with the powder surface chemical properties. Hence, it has been difficult to define the relationship between only the surface chemical properties and materials properties more precisely. Also, it is not clear how the relevant surface properties of silicon nitride should be characterized and quantified. This paper is a part of a review on the surface chemistry of silicon nitride [4]. The focus will be on an overview of the methods that are available to characterize relevant surface properties of ceramic powders, together with a summary on the present understanding of the surface chemistry of silicon nitride.
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| 5. |
- Bergström, L
(författare)
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Rheology of concentrated suspensions
- 1994
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Ingår i: Surface and Colloid Chemistry in Advanced Ceramics Processing. - : Marcel Dekker. ; , s. 193-244
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Bokkapitel (refereegranskat)abstract
- Various aspects of alkyd emulsion technology have been investigated. Firstly, the influence of alkyd oil length, acid value and hydroxyl number, as well as the type of surfactant used as emulsifier, on shear stability of alkyds emulsions have been studied. It was found that the acid value was the most important alkyd parameter, the stability increasing with increasing oil length. It is also shown that anionic surfactants give emulsions with small droplet sizes down at lower concentrations than nonionics. Secondly, polymerizable nonionic surfactants have been tested as emulsifiers and compared with conventional surfactants of the same HLB. It was found that surfactants capable of participating in the autoxidative curing process give faster drying and improved film hardness compared with non-reactive surfactants. Thirdly, the distribution of driers between the alkyd phase and the water phase has been investigated. It was found that low pH and the use of hydrophilic anionic surfactants, such as SDS, favour partitioning of cobalt into the aqueous phase which is unfavourable with respect to drying properties.
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| 6. |
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| 7. |
- Bergström, L, et al.
(författare)
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The effect of wet and dry milling on the surface properties of silicon nitride powders
- 1991
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Ingår i: Ceramics Today. - : Elsevier. ; , s. 1005-1014
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Bokkapitel (refereegranskat)abstract
- The effects of dry milling in air and wet miling in isopropanol, on the surface properties of silicon nitride powders have been investigated. The ground powders have been analyzed with resoect to oxygen and carbon content, electrokinetic behviour, wetting characteristics and adsorption of acidic and basic probe molecules. The results show that dry milling in air leeds to a higher degree of surface oxidation which is correlated to substantially lower isoelectric points for dry milled vs. wet milled powders. The wet milled powders were contaminated by an adsorbed layer of isopropanol which resulted in an initially hydrophobic behaviour and low levels of adsorption of most probe molecules. This coating can be removed by heat treatment at elevated tempratures.
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| 8. |
- Claesson, Per M
(författare)
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The surface force technique : Interactions between surfactant bilayers and between protein layers
- 1994
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Ingår i: Studying Cell Adhesion. - : Springer Berlin/Heidelberg. ; , s. 15-35
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Bokkapitel (refereegranskat)abstract
- Introduction: The forces operating between colloidal particles are of utmost importance for the stability of dispersions and emulsions. Such forces also determine the adhesion between macroscopic surfaces, the adsorption of colloids onto surfaces and they are important in the initial stage of the cell adhesion process. In applied surface chemistry much effort is going into modifying the forces acting between particles in order to give the often complex technical colloidal systems the preferred properties. This has inspired a great deal of fundamental research concerned with determining which types of forces that are operating and how the strength and magnitude of these forces can be varied by addition of additives to the solution or by surface modification techniques. This review will start with a brief recapitulation about the types of forces that are important in colloidal systems and some basic properties of these forces. Next, one important method for studying these forces, the surface force technique, will be described. Finally, the type of information that can be obtained with this technique will be discussed using examples from our studies of surfactant bilayers and of adsorbed protein layers.
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| 9. |
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| 10. |
- Haridi, Seif, et al.
(författare)
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Kernel Andorra Prolog and its computation model
- 1990. - 12
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Ingår i: Logic Programming: Proceedings of the Seventh International Conference. - : MIT Press. - 0262730901
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Bokkapitel (refereegranskat)abstract
- The logic programming language framework Kernel Andorra Prolog is defined by a formal computation model. In Kernel Andorra Prolog, general combinations of concurrent reactive languages and nondeterministic transformational languages may be specified. The framework is based on constraints.
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