| 1. |
- Alander, J, et al.
(author)
-
Model microemulsions containing vegetable oils Part 1: Nonionic surfactant systems
- 1989
-
In: Journal of the American Oil Chemists Society. - 0003-021X .- 1558-9331. ; 66, s. 1656-1660
-
Journal article (peer-reviewed)abstract
- Nonionic microemulsions containing triglucerides and fatty acid esters as lipophilic components have been studied. The phase inversion temperature (PIT) of the systems was determined by a conductometric method. Partial phase diagrams were constructed in the phase inversion temperature range. Water solubilization capacity of the nonionic surfactant systems studied was dependent on surfactant and oil types in analogy to ordinary hydrocarbon systems. The PIT:s increased with increased molecular weight for both esters and triglycerides.
|
|
| 2. |
- Alander, J, et al.
(author)
-
Model microemulsions containing vegetable oils Part 2: Ionic surfactant systems
- 1989
-
In: Journal of the American Oil Chemists Society. - 0003-021X .- 1558-9331. ; 66, s. 1661-1665
-
Journal article (peer-reviewed)abstract
- The phase behavior and the structure of ionic microemulsions, stabilized by sodium oleate and different alcohol cosurfactants, containing fatty acid esters or triglycerides as lipophilic components, have been investigated. Microemulsions containing triglycerides display a smaller stability region than microemulsions containing hydrocarbons or fatty acid esters. From structural investigations, using the NMR FT pulsed gradient spin echo method for measuring self-diffusion coefficients, differences in the microstructure are revealed as well. Adding an ester (or a hydrocarbon) to a microemulsion containing sodium oleate/pentanol will at certain compositions lead to a gradual transition from a bicontinuous to an oilcontinuous system, while this behavior cannot be detected when adding a triglyceride. Instead, a phase-separation occurs, and it is suggested that the larger molecular size of the triglyceride is responsible for the diffirence.
|
|
| 3. |
|
|
| 4. |
- Backlund, S, et al.
(author)
-
Partial phase behavior of ionic microemulsions stabilized by sodium dodecylsulfate and alcohol cosurfactants
- 1992
-
In: Progress in Colloid and Polymer Science. - 0340-255X .- 1437-8027. ; 88, s. 36-41
-
Journal article (peer-reviewed)abstract
- Ionic microemulsions, stabilized by sodium dodecylsulfate and alcohol cosurfactants, have been characterized with respect to phase behavior, particularly the composition of the different phases in Winsor type I, II and III systems. The system containing brine, octane, sodium dodecylsulfate and 1-butanol shows a regular phase behavior, in conformity with the anticipated behavior, i.e., 2-3-2 phases. The phase transitions with increasing 1-butanol concentration are analogous to those occurring with increasing salinity, when compared with previous investigations. For the system containing brine, cyclohexane, sodium dodecylsulfate and benzyl alcohol, the behavior becomes more complex, even at low surfactant contents. The transitions are 2-3-2-3-2 phases over a wide composition range. The compositions of the phases at equilibrium are discussed in relation to structural considerations, as determined by conductivity and NMR self-diffusion measurements.
|
|
| 5. |
- Backlund, S, et al.
(author)
-
Partical phase equilibria and partition of alcohol cosurfactants in ionic microemulsions
- 1990
-
In: Progress in Colloid and Polymer Science. - 0340-255X .- 1437-8027. ; 82, s. 290-295
-
Journal article (peer-reviewed)abstract
- The partial phase behaviour of quintinary microemulsions containing water (0.5 m NaCl), sodium dodecylfate, octane and alcohol, where the alcohol is a butanol or pentanol isomer, has been determined. In addition, the partition of the cosurfactant between the phases has been investigated, as well as in detail for the 1-butanol system. The efficiency of the cosurfactant for forming microemulsions is found to exhibit no simple relationship to its solubility properties. In addition, while branched alcohol cosurfactants promote the formation of solution phases at high surfactant contents.
|
|
| 6. |
|
|
| 7. |
- Blomberg, E, et al.
(author)
-
Surface interactions in emulsion and liposome solutions
- 1999
-
In: Colloids and Surfaces A. - 0927-7757 .- 1873-4359. ; 159, s. 149-157
-
Journal article (peer-reviewed)abstract
- We have used two surface force techniques to investigate the interactions between hydrophilic and negatively charged mica and glass surfaces across concentrated and dilute oil-in-water emulsions, as well as across aqueous liposome solutions. It was observed with both the interferometric surface force apparatus, using mica surfaces, and with the non-interferometric MASIF technique, employing glass surfaces, that emulsion droplets adsorbed onto the surfaces. Under a high compressive force the adsorbed emulsion droplets were disintegrated and this resulted in a phase separation in the gap between the surfaces. The forces measured in the presence of the capillary condensate compared favourably with theoretical expectations. In contrast, no adsorption of large aggregates could be detected in the liposome solution. Instead it appears that upon adsorption the liposomes disintegrate and the surfaces become covered by a disordered layer of phospholipids. Measurements with the interferometric surface force apparatus, that allows absolute distances to be determined, allow us to draw the conclusion that some bilayer aggregates are adsorbed and that the inner layer consists of an intercalated monolayer.
|
|
| 8. |
|
|
| 9. |
- Friberg, SE, et al.
(author)
-
Hydrotropes – performance chemicals
- 2004
-
In: Journal of Dispersion Science and Technology. - 0193-2691 .- 1532-2351. ; 25, s. 243-251
-
Journal article (peer-reviewed)abstract
- The action of hydrotropes is reviewed emphasizing their influence in the formation of microemulsions, vesicle solutions and other products involving surfactant association structures. It is demonstrated that the hydrotropes, the association structures of which, realistically, can only be described as trivial, actually, are powerful and sophisticated performance chemicals playing an essential role in complex applied formulations utilizing more composite amphiphilic association structures
|
|
| 10. |
- Jonströmer, M, et al.
(author)
-
Aggregation and solvent interaction in nonionic surfactant systems with formamide
- 1990
-
In: Journal of Physical Chemistry A. - 1089-5639 .- 1520-5215. ; 94, s. 7549-7555
-
Journal article (peer-reviewed)abstract
- The self-association and solvent interaction of some polyethylene glycol alkyl ether surfactants (CxEy) in fornamide have been studied via determinations of phase diagrams and NMR self-diffusion measurements. For C12E3 and C12 E4, small micelles but no liquid chrystalline phases form. Increasing the alkyl chain length to hexadecyl (C16E4, C16E6, and C16E8), mesophase formation occurs analogously to the corresponding aqueous system. No aggregate growth occurs in the micellar phase, neither at high temperatures and high surfactant concentrations nor when approaching the lower consolute temperature. The solvent diffusion was analyzed within the cell diffusion model, and a concentration-independent amount of 1-5 and probably not more than 3 formamide molecules was found to interact with each ethylene oxide group. Furthermore, the calculations indicated a ploymer-like state of the micellar headgroup shell, with a slight decrease of the formamide content therein at a raised temperature. In conclusion, the behaviour of CxEy/formamide systems is qualitatively similar to that of the corresponding aqueous sytem.
|
|
