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Bydén Sjöbom, Malin
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Publications (6 of 6) Show all publications
Bydén Sjöbom, M., Marques, E., Edlund, H. & Khan, A. (2005). Phase Equilibria of the Mixed Didodecyldimethylammonium Bromide-Taurodeoxycholate-Water System with a Large Solution Region.. Colloids and Surfaces, 269(1-3), 87-95
Open this publication in new window or tab >>Phase Equilibria of the Mixed Didodecyldimethylammonium Bromide-Taurodeoxycholate-Water System with a Large Solution Region.
2005 (English)In: Colloids and Surfaces, ISSN 0166-6622, E-ISSN 1873-4340, Vol. 269, no 1-3, p. 87-95Article in journal (Refereed) Published
Abstract [en]

The phase behavior over the entire concentration range for the system didodecyldimethylammonium bromide (DDAB)-sodium taurodeoxycholate (STDC)-water, at 25 degrees C, has been investigated, with emphasis on the DDAB-rich part. Polarizing microscopy, SAXS, H-2 NMR and H-1 self-diffusion NMR have been used in combination as probing techniques for phase behavior and microstructure. The system forms four major phases, all deriving from the respective binary surfactant systems. The two lamellar phases originating from the binary DDAB-water axis (D-I and D-II, at 3-30 and 83-91 wt.% DDAB, respectively) are only able to incorporate small amounts of STDC. The D-II phase solubilizes a comparatively higher amount of bile salt (up to ca. 6 wt.%), while the D, phase takes up less than 0.25 wt.%. From the STDC-water axis, a solution phase and a "hexagonal-like" liquid crystalline phase are derived, at 0-26 and 37-60 wt.% of STDC, respectively. Heterogeneous regions are also indicated on the basis of NMR and SAXS data. The most striking feature is the large extension of the isotropic solution phase, which originates from the water corner and curves toward the DDAB-rich side of the phase diagram. Even though at the upper limit of the solution phase the amount of water is reduced to 10 wt.%, the measured water and DDAB self-diffusion coefficients exclude the possibility of reverse-type structures.

Keywords
Surfactant
National Category
Chemical Sciences
Identifiers
urn:nbn:se:miun:diva-3741 (URN)10.1016/j.colsurfa.2005.06.066 (DOI)000233262200012 ()4013 (Local ID)4013 (Archive number)4013 (OAI)
Note
VR-ChemistryAvailable from: 2008-09-30 Created: 2009-06-08 Last updated: 2017-12-12Bibliographically approved
Bydén Sjöbom, M., Hedenström, E. & Edlund, H. (2003). Binary Phase Equilibria of Three alfa-Methylsubstituted Sodium Alkanoate Surfactant Systems.. Journal of Colloid and Interface Science, 257(2), 333-336
Open this publication in new window or tab >>Binary Phase Equilibria of Three alfa-Methylsubstituted Sodium Alkanoate Surfactant Systems.
2003 (English)In: Journal of Colloid and Interface Science, ISSN 0021-9797, Vol. 257, no 2, p. 333-336Article in journal (Refereed) Published
Abstract [en]

In this work, we continue our study of methyl -substituted surfactants and present the aqueous binary phase diagrams of racemic sodium 2-methyloctanoate, -nonanoate, and -dodecanoate, respectively. All systems have very low Krafft temperatures within the solution phase, between 1 and 4 degreesC. The phase sequences of the two shorter surfactants are very similar to those of the unsubstituted sodium octanoate, although with somewhat different range of existence for the phases formed. The sodium 2-methyldodecanoate system is different from the unsubstituted sodium dodecanoate system, as the former seems to lack a hexagonal phase. The surfactant systems were delineated using H-2 NMR splittings and crossed polarizers, and combined with SAXS for determination of phase structure. 

Keywords
surfaktanter
National Category
Chemical Sciences
Identifiers
urn:nbn:se:miun:diva-1840 (URN)10.1016/S0021-9797(02)00038-3 (DOI)000180947700020 ()16256488 (PubMedID)0037440367 (Scopus ID)604 (Local ID)604 (Archive number)604 (OAI)
Available from: 2008-09-30 Created: 2008-09-30 Last updated: 2016-09-29Bibliographically approved
Bydén Sjöbom, M. & Edlund, H. (2002). Dependence of Alkyl Chain Asymmetry on the Phase Equilibria of Three Catanionic Surfactant Mixtures Containing Dodecyltrimethylammonium Chloride-Sodium Alkylcarboxylate-Water. Langmuir, 18(22), 8309-8317
Open this publication in new window or tab >>Dependence of Alkyl Chain Asymmetry on the Phase Equilibria of Three Catanionic Surfactant Mixtures Containing Dodecyltrimethylammonium Chloride-Sodium Alkylcarboxylate-Water
2002 (English)In: Langmuir, ISSN 0743-7463, Vol. 18, no 22, p. 8309-8317Article in journal (Refereed) Published
Keywords
catanionic, surfactant mixture
National Category
Chemical Sciences
Identifiers
urn:nbn:se:miun:diva-1891 (URN)10.1021/la0203234 (DOI)000178839300009 ()2-s2.0-0037195367 (Scopus ID)709 (Local ID)709 (Archive number)709 (OAI)
Available from: 2008-09-30 Created: 2008-09-30 Last updated: 2016-10-21Bibliographically approved
Bydén Sjöbom, M., Edlund, H. & Lindström, B. (1999). BinaBinary Phase Equilibria and Structure of the Two α-Methyl-Substituted Surfactants Sodium (R)-2-Methyldecanoate and Racemic Sodium 2-Methyldecanoate ry Phase Exuilibria and Structure of the Chiral α-Methylsubstituted Surfactants Sodium (R)-2-Methyldecanoate and Racemic Sodium 2-Methyldecanoate. Langmuir, 15(8), 2654-2660
Open this publication in new window or tab >>BinaBinary Phase Equilibria and Structure of the Two α-Methyl-Substituted Surfactants Sodium (R)-2-Methyldecanoate and Racemic Sodium 2-Methyldecanoate ry Phase Exuilibria and Structure of the Chiral α-Methylsubstituted Surfactants Sodium (R)-2-Methyldecanoate and Racemic Sodium 2-Methyldecanoate
1999 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 15, no 8, p. 2654-2660Article in journal (Refereed) Published
Abstract [en]

In this study, we present the binary phase diagrams for the aqueous systems of the alkyldecanoic salts racemic sodium 2-methyldecanoate and sodium (R)-2-methyldecanoate, respectively. Both systems form a micellar solution phase, as well as a normal hexagonal, a cubic, and a lamellar liquid crystalline phase. They also form a very narrow intermediate phase, situated between the hexagonal and cubic liquid crystalline phases. The methods used for characterization were crossed polaroids, polarizing optical microscope and 2H NMR quadrupolar splittings combined with SAXS studies. The cubic phase gave a well-resolved SAXS diffraction pattern, with eight peaks present, which establishes the bicontinuous cubic structure as Ia3d. A significant difference in these two phase diagrams, compared to those of unsubstituted alkanoates with the same chain length, is the very low Krafft boundary.

National Category
Chemical Sciences
Identifiers
urn:nbn:se:miun:diva-8448 (URN)10.1021/la980343z (DOI)
Available from: 2009-01-26 Created: 2009-01-26 Last updated: 2017-12-14Bibliographically approved
Edlund, H., Bydén, M., Lindström, B. & Khan, A. (1998). Phase Equilibria and Structure of the 1-dodecyl Pyridinium Bromide-Dodecane-Water System. Journal of Colloid and Interface Science, 204(2), 312-319
Open this publication in new window or tab >>Phase Equilibria and Structure of the 1-dodecyl Pyridinium Bromide-Dodecane-Water System
1998 (English)In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 204, no 2, p. 312-319Article in journal (Refereed) Published
Abstract [en]

The isothermal ternary phase diagram for the 1-dodecylpyridinium bromide/dodecane/water system was determined at 40°C by 2H NMR and polarizing microscopy methods. Two liquid crystalline phases, a large cubic area and a normal hexagonal phase, and one isotropic normal micellar solution phase were characterized, and their ranges of existence were determined. The micelles were found to be probably small and spherical at lower concentrations of surfactant, and were found to grow at higher concentrations and on addition of oil. The two-phase areas, L1 + H1 and H1 + I, are both very narrow. The comparatively large cubic area, containing 43-63 wt% surfactant and 3-10 wt% dodecane, is probably consistent of more than one structure. SAXS experiments indicate two different structures built of discrete micellar aggregates.

National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-8449 (URN)
Available from: 2009-01-26 Created: 2009-01-26 Last updated: 2017-12-14Bibliographically approved
Edlund, H., Bydén, M., Lindström, B. & Khan, A. (1997). Ternary Phase Equilibria of the 1.dodecyl Pyridinium Bromide-Dodecanol-Water System. Journal of Colloid and Interface Science, 196(2), 231-240
Open this publication in new window or tab >>Ternary Phase Equilibria of the 1.dodecyl Pyridinium Bromide-Dodecanol-Water System
1997 (English)In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 196, no 2, p. 231-240Article in journal (Refereed) Published
Abstract [en]

The isothermal ternary phase diagram for the 1-dodecylpyridinium bromide (1-DPB)–water–dodecanol system was determined at 40°C, using2H NMR, polarizing microscopy, and SAXS methods. All of the phases were characterized, and their ranges of existence were determined. The surfactant is easy to dissolve in water, yielding a normal micellar solution phase. After the normal micellar phase, on the binary surfactant–water axis, a normal hexagonal liquid crystalline phase is found at higher surfactant concentrations. On addition of dodecanol, four more phases are formed, i.e. a cubic, a lamellar, and a reverse hexagonal phase, followed by a reverse micellar solution phase. The lamellar liquid crystalline phase dominates the ternary phase diagram. The structures of the liquid crystalline phases were further examined using SAXS measurements, and the results are discussed in terms of the critical packing parameter, cpp, and electrostatic forces. The SAXS experiments show a pronounced swelling of the rods in the hexagonal phase, from 28.5 to 33 Å on addition of dodecanol, whereas the cylindrical aqueous core of the reverse hexagonal phase has a diameter of 18–21 Å, depending on sample composition. The average bilayer thickness of the lamellar phase is about 24 Å.

National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-8450 (URN)10.1006/jcis.1997.5206 (DOI)
Available from: 2009-01-26 Created: 2009-01-26 Last updated: 2017-12-14Bibliographically approved
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