| 1. |
- Johansson, L. B. A., et al.
(författare)
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Micelle studies by high-sensitivity linear dichroism. Benzene solubilization in rod-shaped micelles of cetyltrimethylammoniumbromide in water
- 1976
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Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614. ; 39:1, s. 128-133
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Tidskriftsartikel (refereegranskat)abstract
- A high-sensitivity linear dichroism (LD) technique has been employed in studying the indirect orientation of benzene by solubilization in rod-shaped micelles in a system of cetyltrimethylammoniumbromide (CTAB): water, oriented by flow in a couvette device. The dependence of the LD signal due to the π-π* transitions in the benzene plane on the temperature, on the shear gradient and on the benzene concentration, has been investigated. The net positive LD, observed from the benzene chromophore, derives from benzene orientation at the surface of the rod-shaped micelles. The orientation of the micelle rods is very high and the system is suggested for use as a standard matrix for studying solubilized molecules in polarized spectroscopy.
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| 2. |
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| 3. |
- Jonas, I., et al.
(författare)
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Orientation Studies of Probe Molecules in Lamellar Liquid Crystalline Lipid Systems by Linear Dichroism
- 1977
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Ingår i: Spectroscopy Letters. - : Informa UK Limited. - 1532-2289 .- 0038-7010. ; 10:6, s. 501-506
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Tidskriftsartikel (refereegranskat)abstract
- The LD-method of inclined incidence was found useful in the study of the orientations of probe chromophores (carotene, anthracene) solubilized in lamellar mesophases of the systems sodium octanoate/decanol/water and sodium di-2-ethylhexylsulphosuccinate/water, respectively. The results suggest the existence of two competing molecular orientation mechanisms aligning the longest axis of the probe molecule either parallel with the lamellar surface or perpendicular to it.
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| 4. |
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| 5. |
- Nordén, Bengt, 1945, et al.
(författare)
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Linear dichroism spectroscopy as a tool for studying molecular orientation in model membrane systems
- 1977
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Ingår i: Journal of Physical Chemistry. - : American Chemical Society (ACS). - 0022-3654 .- 1541-5740. ; 81:22, s. 2086-2093
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Tidskriftsartikel (refereegranskat)abstract
- Ordinary linear dichroism (LD) spectroscopy with rectangular optics is not applicable to thin uniaxial sampleshaving the optical axis perpendicular to the plane of the sample. A method has been developed to study suchsamples at inclined optical incidence and a general relation derived between the LD (corrected for polarizedreflection) and the average orientation of the absorbing transition dipole. For molecules of C2”, D2h, or highersymmetry the usual order parameters can be obtained. The method has been tested on anthracene in apolyethylene standard slab of perfectly axial symmetry. The estimated orientation agreed with previous reportson anthracene in stretched polyethylene sheets. A number of chromophoric molecules solubilized in macroscopicallyaligned lamellar mesophases of the systems sodium octanoate/decanol/water and sodium di-2-ethylhexylsulfosuccinate (Aerosol OT)/water have also been studied. In the first system rodlike molecules(diphenylethyne, anthracene, retinal) are oriented with their long axes parallel to the hydrocarbon chains ofthe amphiphile, while an extremely long molecule (&carotene) as well as water-soluble planar cationic dyesare on the average oriented parallel to the lamellar planes. In the Aerosol OT system all molecules studiedwere oriented parallel to the lamellar planes.
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