| 1. |
- Almgren, Mats, et al.
(author)
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Cryotransmission electron microscopy of thin vitrified samples.
- 1996
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In: Current Opinion in Colloid & Interface Science. - 1359-0294 .- 1879-0399. ; 1:2, s. 270-278
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Journal article (peer-reviewed)abstract
- During the past few years cryotransmission electron microscopy (EM) of vitrified thin samples has gained acceptance as a standard method in the arsenal of the colloid and interface scientist. The seemingly direct visualization of fluid colloidal structures during the use of cryotransmission EM is both convincing and reliable to the scientist who nowadays has an increasing awareness of the limitations and pitfalls of instrumentation. Notable recent observations include branched threadlike micelles, faceted particles (cubosomes) of a dispersed cubic phase and transitions of certain structures from globular micelles via bilayers to reversed structures. These transitions may be caused by changes of compos ition, temperature, pH, or salt concentration.
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| 2. |
- Gustafsson, Jonas, et al.
(author)
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A defective swelling lamellar phase
- 1997
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In: LANGMUIR. - : AMER CHEMICAL SOC. - 0743-7463. ; 13:4, s. 852-860
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Journal article (peer-reviewed)abstract
- The phase equilibria in mixtures of egg lecithin and cetyltrimethylammonium chloride in brine (100 mM sodium chloride) were studied with particular emphasis on the behavior of the lamellar phase. The solvent corner of this pseudoternary system features an
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| 3. |
- Gustafsson, Jonas, et al.
(author)
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Cubic lipid-water phase dispersed into submicron particles
- 1996
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In: Langmuir. ; 12:20, s. 4611-4613
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Journal article (peer-reviewed)abstract
- The formation of dispersed colloidal particles of a bilayer cubic phase is demonstrated and discussed in relation to the phase behavior of the components used. Examination by means of cryotransmission electron microscopy reveals submicron particles of fac
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| 4. |
- Gustafsson, Jonas, et al.
(author)
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Disintegration of the lecithin lamellar phase by cationic surfactants
- 1997
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In: LANGMUIR. - : AMER CHEMICAL SOC. - 0743-7463. ; 13:26, s. 6956-6963
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Journal article (peer-reviewed)abstract
- The phase behavior of egg lecithin mixed with two cationic surfactants, hexadecyl- and dodecyltrimethylammonium chloride (C(16)TAC and C(12)TAC, respectively), in brine (100 mM NaCl) has been studied. Combining results from NMR spectroscopy, small-angle X
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| 5. |
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| 6. |
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| 7. |
- Orädd, Greger, et al.
(author)
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Intermediate phases in the system egg lecithin/CTAC/brine. SAXS and NMR studies
- 2001
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In: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 17:11, s. 3227-34
-
Journal article (peer-reviewed)abstract
- The phase behavior and phase structures in the pseudo ternary system egg lecithin (EPC)/ cetyltrimethylammonium chloride/brine (100 mM NaCl) have been investigated by H-2 and P-31 NMR spectroscopy and small-angle X-ray diffraction (SAXS). At solvent contents higher than 55 wt %, micellar, hexagonal, and lamellar phases are formed. At lower solvent content, an intermediate phase occurs consisting of rods with noncircular cross-sections farming a centered rectangular phase of space symmetry c2mm. This phase is connected to both the lamellar phase and the hexagonal phase by two-phase regions. There is a large region of the lamellar phase where the bilayers contain water-filled defects in the form of pores and/or slits. SAXS diffractograms from the defect lamellar phase exhibit interlamellar Bragg reflections as well as a broad reflection originating from the water-filled defects. The variation of the distances obtained as a function of water content and CTAC/EPC ratio is consistent with theoretical predictions on water-filled defects in lamellae. The rectangular phase is characterized by several sharp SAXS reflections which have been indexed to the space group c2mm. The NMR line shapes are of biaxial symmetry with an asymmetry parameter ranging from 0.6 to 1.0. From an analysis of the SAXS and NMR data, we have found evidence of molecular segregation in that lecithin is enriched in the flat regions of the noncircular cylinders.
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