Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Molecular Association Studied by NMR Spectroscopy
KTH, School of Chemical Science and Engineering (CHE), Chemistry, Physical Chemistry.
2006 (English)Doctoral thesis, comprehensive summary (Other scientific)
Abstract [en]

This Thesis presents studies of molecular association in aqueous solution and at the liquid/solid interface. The investigated molecular systems range from self-aggregating surfactants to hydration water in contact with micelles or individual molecules. In most studies, combinations of various NMR methods were applied. These vary from simple chemical shift and intensity measurements to more elaborate self-diffusion and intermolecular cross-relaxation experiments.

Non-ideal mixed micelles of fluorinated and hydrogenated surfactants were studied by an experimental procedure that allows an analysis in terms of micellar structure, using a minimal number of initial assumptions. Quantitative conclusions about micro-phase separation within mixed micelles were obtained within the framework of the regular solution theory. Additionally, NMR was introduced and developed as a powerful method for studying adsorption of surfactants at solid interfaces. Adsorption isotherms for pure and mixed surfactant systems and non-ideal mixing behavior of fluorinated and hydrogenated surfactants at solid surfaces were quantified. Fluorosurfactant-protein association was investigated using the methods described.

Intermolecular cross-relaxation rates between solute and solvent molecules were recorded at several different magnetic fields. The results reveal strong frequency dependence for both small molecules and micelles. This finding demonstrates that intermolecular cross-relaxation is not solely controlled by fast local motions, but also by long-range translational dynamics. Data analysis in terms of recently developed relaxation models provides information about the hydrophobic hydration and micellar structure.

Place, publisher, year, edition, pages
Stockholm: KTH , 2006. , 52 p.
Series
Trita-FYK, 0602
Keyword [en]
NMR, spin relaxation, self-diffusion, intermolecular cross-relaxation, chemical shift, fluorinated surfactants, hydrogenated surfactant, micelle, non-ideal mixing, adsorption, hydration, surfactant-protein association
National Category
Physical Chemistry
Identifiers
URN: urn:nbn:se:kth:diva-3947ISBN: 91-7178-345 8 (print)OAI: oai:DiVA.org:kth-3947DiVA: diva2:10139
Public defence
2006-05-19, F3, Lindstedtsv. 26, Stockholm, 10:00
Opponent
Supervisors
Note
QC 20100914Available from: 2006-05-10 Created: 2006-05-10 Last updated: 2010-09-14Bibliographically approved
List of papers
1. Adsorption Isotherm and Aggregate Properties of Fluorosurfactants on Alumina Measured by 19F NMR
Open this publication in new window or tab >>Adsorption Isotherm and Aggregate Properties of Fluorosurfactants on Alumina Measured by 19F NMR
2002 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 18, no 21, 8096-8101 p.Article in journal (Refereed) Published
Abstract [en]

The adsorption and self-assembly of ammonium perfluorooctanoate (APFO) at surfaces of porous alumina immersed in solution at pH similar to 4 have been studied using F-19 NMR. From the intensity of the APFO NMR signals, the amount of adsorbed surfactant, and thereby the adsorption isotherm, was determined. The adsorption isotherm indicates that APFO forms bilayers on alumina. This result is supported by finding the CF3 signal of adsorbed APFO shifted upfield compared to the signal in aqueous solution with an amount that corresponds to a change from aqueous to fluorocarbon environment. Additionally, faster transverse relaxation of the fluorine nuclei adjacent to the head group compared to that of the CF3 group adds a further argument for the formation of a bilayer. The exchange pattern of surfactants between the adsorbed layer and the aqueous bulk was studied through the CF3 group F-19 signals and their time-averaged behavior. Inside the pores of the alumina particles, the exchange time was found to be fast (much less than1 ms) between adsorbed and dissolved APFO. The presented NMR method to determine the adsorption isotherm could be a powerful new tool when studying systems of mixed surfactants, since the adsorbed amount of chemically different surfactants and their formation in aggregates would become separately quantifiable. The method is readily applicable to any NMR nuclei and thereby to many adsorption problems.

Keyword
Adsorption; Aggregates; Alumina; Ammonium compounds; Dissolution; Fluorocarbons; Isotherms; Nuclear magnetic resonance; pH effects; Porous materials; Self assembly; Solutions
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-5686 (URN)10.1021/la026014v (DOI)000178589700050 ()
Note
QC 20100826Available from: 2006-05-10 Created: 2006-05-10 Last updated: 2017-12-14Bibliographically approved
2. Mixed Micelles of Fluorinated and Hydrogenated Surfactants
Open this publication in new window or tab >>Mixed Micelles of Fluorinated and Hydrogenated Surfactants
2006 (English)In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 128, no 20, 6704-6712 p.Article in journal (Refereed) Published
Abstract [en]

The model mixed surfactant system of sodium perfluorooctanoate and sodium decyl sulfate was carefully reexamined by a combination of nuclear magnetic resonance methods. Over a wide range of sample compositions, detailed F-19 and H-1 chemical shift data in combination with self-diffusion coefficients for the perfluorooctanoate and decyl sulfate ions are collected. All data are analyzed together in a framework that uses a minimal number of initial assumptions to extract the monomer concentrations of both surfactants and the micellar chemical shifts of F-19 and H-1 as a function of relative concentration. The main conclusion drawn from this analysis is that there exists neither complete demixing nor complete mixing on molecular or micellar levels. Instead, the experimental data favor a single type of micelles within which fluorinated surfactants are preferentially coordinated by fluorinated ones and hydrogenated surfactants by hydrogenated ones. The data are quantitatively interpreted in the framework of the first approximation of the regular solution theory (also called the quasi-chemical treatment) leading to an energy of mixing of omega = W/kT = 0.98 between the constituting surfactant types. These findings may help to resolve a long controversy about micellar mixing-demixing in this particular mixture and in its relatives.

Keyword
Angle neutron-scattering, self-diffusion measurements, nuclear magnetic-resonance, order-parameter profile, sodium perfluorooctanoate, hydrocarbon surfactants, aggregation number, aqueous-solutions, chemical-shifts, fluorocarbon surfactants
National Category
Physical Chemistry
Identifiers
urn:nbn:se:kth:diva-5687 (URN)10.1021/ja061029r (DOI)000237590500045 ()2-s2.0-33646721758 (Scopus ID)
Note
QC 20100914Available from: 2006-05-10 Created: 2006-05-10 Last updated: 2017-12-14Bibliographically approved
3. Mixed Adsorption of Fluorinated and Hydrogenated Surfactants
Open this publication in new window or tab >>Mixed Adsorption of Fluorinated and Hydrogenated Surfactants
2006 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 22, no 19, 7969-7974 p.Article in journal (Refereed) Published
Abstract [en]

The adsorption isotherms of sodium perfluorooctanoate and sodium decyl sulfate and their 1:1 mixture on gamma-alumina are recorded by depletion-type experiments with H-1 and F-19 NMR spectroscopy as the detection tool. The isotherms of the different surfactant species, obtained with and without added salt, closely resemble each other. Salt addition changes the isotherms from stepwise to the familiar S-shaped. After having reached saturation, a further increase of surfactant concentration in the mixed system leads to decyl sulfate desorption and increased perfluorooctanoate adsorption. The F-19 chemical shift of adsorbed perfluorooctanoate suggests that, for saturated surfaces, the two sorts of adsorbed surfactants form molecularly mixed surface aggregates.

Keyword
mineral oxide surfaces, self-assembled monolayers, ferric hydro sols, fluorocarbon surfactants, aqueous-solutions, anionic surfactants, binary-mixtures, magnetic-resonance, nmr-spectroscopy, sodium perfluorooctanoate
National Category
Physical Chemistry
Identifiers
urn:nbn:se:kth:diva-5688 (URN)10.1021/la060757p (DOI)000240250600007 ()2-s2.0-33748786774 (Scopus ID)
Note
QC 20100914Available from: 2006-05-10 Created: 2006-05-10 Last updated: 2017-12-14Bibliographically approved
4. Solute-Solvent Contact by Intermolecular Cross Relaxation: I. The Nature of the Water-Hydrophobic Interface
Open this publication in new window or tab >>Solute-Solvent Contact by Intermolecular Cross Relaxation: I. The Nature of the Water-Hydrophobic Interface
2006 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 125, no 7, 074704- p.Article in journal (Refereed) Published
Abstract [en]

Intermolecular cross-relaxation rates between solute and solvent were measured by {H-1} F-19 nuclear magnetic resonance experiments in aqueous molecular solutions of ammonium perfluoro-octanoate and sodium trifluoroacetate. The experiments performed at three different magnetic fields provide frequency-dependent cross-relaxation rates which demonstrate clearly the lack of extreme narrowing for nuclear spin relaxation by diffusionally modulated intermolecular interactions. Supplemented by suitable intramolecular cross-relaxation, longitudinal relaxation, and self-diffusion data, the obtained cross-relaxation rates are evaluated within the framework of recent relaxation models and provide information about the hydrophobic hydration. In particular, water dynamics around the trifluoromethyl group in ammonium perfluoro-octanoate are more retarded than that in the smaller trifluoroacetate

Keyword
molecular-dynamics simulation, overhauser effect measurements, nuclear-spin relaxation, pair correlation-functions, low ionic-strength, nmr relaxation, magnetic-resonance, carboxylic-acids, translational diffusion, electronic relaxation
National Category
Physical Chemistry
Identifiers
urn:nbn:se:kth:diva-5689 (URN)10.1063/1.2336199 (DOI)000239914800046 ()2-s2.0-33747624412 (Scopus ID)
Note
Uppdaterad från submitted till published: 20100914 QC 20100914Available from: 2006-05-10 Created: 2006-05-10 Last updated: 2017-12-14Bibliographically approved
5. Solute-Solvent Contact by Intermolecular Cross Relaxation: II. The Water-Micelle Interface and the Micellar Interior
Open this publication in new window or tab >>Solute-Solvent Contact by Intermolecular Cross Relaxation: II. The Water-Micelle Interface and the Micellar Interior
2006 (Swedish)In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 110, no 51, 25775-25781 p.Article in journal (Refereed) Published
Abstract [en]

The intermolecular dipole-dipole cross-relaxation is measured between F-19 nuclei of sodium perfluorooctanoate in micelles and H-1 nuclei of the water solvent. The cross-relaxation rates for fluorines in the different moieties along the surfactant vary strongly by the resonance frequency in the investigated range of 188-470 MHz. This frequency dependence indicates that the cross-relaxation between water and amphiphilic aggregates is not controlled solely by the fast local water dynamics but significantly contributed to by the long-range translational diffusion of water. The cross-relaxation rates, analyzed in the framework of a model (Nordstierna, L.; Yushmanov, P. V.; Furo, I. J. Chem. Phys. 2006, 125, 074704), provide information about the dynamic retardation of water molecules by the micellar headgroup region and the location of the various moieties along the hydrophobic tail with respect to the water-micelle interface. Both intermolecular cross-relaxation and aggregation-induced F-19 chemical shift changes indicate no direct water contact to fluorines except for those closest to the head group.

Keyword
nuclear-magnetic-resonance, overhauser effect measurements, molecular-dynamics simulation, ionic surfactant micelles, order-parameter profile, sodium dodecyl-sulfate, spin relaxation, magic-angle, translational diffusion, conformational-analysis
National Category
Physical Chemistry
Identifiers
urn:nbn:se:kth:diva-5690 (URN)10.1021/jp0647885 (DOI)000242974300038 ()2-s2.0-33846400071 (Scopus ID)
Note
Uppdaterad från submitted till published: 20100914 QC 20100914Available from: 2006-05-10 Created: 2006-05-10 Last updated: 2017-12-14Bibliographically approved
6. Lack of association between a cationic protein and a cationic fluorosurfactant
Open this publication in new window or tab >>Lack of association between a cationic protein and a cationic fluorosurfactant
Show others...
2007 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 23, no 2, 771-775 p.Article in journal (Refereed) Published
Abstract [en]

Surface tension, F-19 and H-1 NMR spectroscopy, and cryotransmission electron microscopy are used to characterize the state of association in aqueous solutions of a fluorosurfactant CF3(CF2)(n)SO2NH(CH2)(3-4)N(CH3)(3)(+) I- (n = 8, 6) with and without lysozyme added. In the absence of lysozyme, we find monomers, small aggregates, and large vesicles to coexist, with the individual fluorosurfactant molecules exchanging slowly (> 1 ms) among those states. When both lysozyme and fluorosurfactant are present in the solution, they have no measurable influence on the physical state of the other. In contrast, a hydrogenated cationic surfactant with the same headgroup, hexadecyltrimethylammonium bromide, is shown to associate to lysozyme.

Keyword
Fluorescence; Monomers; Nuclear magnetic resonance; Proteins; Solutions; Surface tension; Transmission electron microscopy; Cationic fluorosurfactants; Cationic proteins; Cryotransmission electron microscopy; Individual fluorosurfactant molecules; Surface active agents; cation; cetrimide; lysozyme; surfactant; article; chemical structure; chemistry; cryoelectron microscopy; hydrogen bond; methodology; nuclear magnetic resonance spectroscopy; physical chemistry; protein folding; surface property; surface tension; transmission electron microscopy; Cations; Cetrimonium Compounds; Chemistry, Physical; Cryoelectron Microscopy; Hydrogen Bonding; Magnetic Resonance Spectroscopy; Microscopy, Electron, Transmission; Molecular Structure; Muramidase; Protein Folding; Surface Properties; Surface Tension; Surface-Active Agents
National Category
Physical Chemistry
Identifiers
urn:nbn:se:kth:diva-7413 (URN)10.1021/la062469z (DOI)000243338500061 ()17209632 (PubMedID)2-s2.0-33846852625 (Scopus ID)
Note

QC 20150721

Available from: 2009-08-30 Created: 2009-08-30 Last updated: 2017-12-14Bibliographically approved

Open Access in DiVA

fulltext(263 kB)1047 downloads
File information
File name FULLTEXT01.pdfFile size 263 kBChecksum MD5
a5e6f2b7d5f2ca69d89bb71c0e64205deb18d22d2c7f4c15747ce1f569f921c437d10f7c
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Nordstierna, Lars
By organisation
Physical Chemistry
Physical Chemistry

Search outside of DiVA

GoogleGoogle Scholar
Total: 1047 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 721 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf