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
Characterizing ions in solution by NMR methods
KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

NMR experiments performed under the effect of electric fields, either continuous or pulsed, can provide quantitative parameters related to ion association and ion transport in solution.  Electrophoretic NMR (eNMR) is based on a diffusion pulse-sequence with electric fields applied in the form of pulses. Magnetic field gradients enable the measurement of the electrophoretic mobility of charged species, a parameter that can be related to ionic association.

The effective charge of the tetramethylammonium cation ion in water, dimethylsulphoxide (DMSO), acetonitrile, methanol and ethanol was estimated by eNMR and diffusion measurements and compared to the value predicted by the Debye-Hückel-Onsager limiting law. The difference between the predicted and measured effective charge was attributed to ion pairing which was found to be especially significant in ethanol.

The association of a large set of cations to polyethylene oxide (PEO) in methanol, through the ion-dipole interaction, was quantified by eNMR. The trends found were in good agreement with the scarce data from other methods. Significant association was found for cations that have a surface charge density below a critical value. For short PEO chains, the charge per monomer was found to be significantly higher than for longer PEO chains when binding to the same cations. This was attributed to the high entropy cost required to rearrange a long chain in order to optimize the ion-dipole interactions with the cations. Moreover, it was suggested that short PEO chains may exhibit distinct binding modes in the presence of different cations, as supported by diffusion measurements, relaxation measurements and chemical shift data.

The protonation state of a uranium (VI)-adenosine monophosphate (AMP) complex in aqueous solution was measured by eNMR in the alkaline pH range. The question whether or not specific oxygens in the ligand were protonated was resolved by considering the possible association of other species present in the solution to the complex.

The methodology of eNMR was developed through the introduction of a new pulse-sequence which suppresses artifactual flow effects in highly conductive samples.

In another experimental setup, using NMR imaging, a constant current was applied to a lithium ion (Li ion) battery model. Here, 7Li spin-echo imaging was used to probe the spin density in the electrolyte and thus visualize the development of Li+ concentration gradients. The Li+ transport number and salt diffusivity were obtained within an electrochemical transport model. The parameters obtained were in good agreement with data for similar electrolytes. The use of an alternative imaging method based on CTI (Constant Time Imaging) was explored and implemented.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2014. , xii, 58 p.
Series
TRITA-CHE-Report, ISSN 1654-1081 ; 2014:29
Keyword [en]
electrophoretic NMR, diffusion NMR, NMR imaging, ion pairing, ion association, polyethylene oxide, metal-ion complex, Li ion batteries, electrolyte characterization
National Category
Natural Sciences
Research subject
Chemistry
Identifiers
URN: urn:nbn:se:kth:diva-149552ISBN: 978-91-7595-208-6 (print)OAI: oai:DiVA.org:kth-149552DiVA: diva2:740082
Public defence
2014-09-12, F3, Lindstedtsvägen 26, KTH, Stockholm, 14:00 (English)
Opponent
Supervisors
Funder
Swedish Research CouncilKnut and Alice Wallenberg Foundation
Note

QC 20140825

Available from: 2014-08-25 Created: 2014-08-22 Last updated: 2014-08-25Bibliographically approved
List of papers
1. Quantifying mass transport during polarization in a Li Ion battery electrolyte by in situ 7Li NMR imaging
Open this publication in new window or tab >>Quantifying mass transport during polarization in a Li Ion battery electrolyte by in situ 7Li NMR imaging
Show others...
2012 (English)In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 134, no 36, 14654-14657 p.Article in journal (Refereed) Published
Abstract [en]

Poor mass transport in the electrolyte of Li ion batteries causes large performance losses in high-power applications such as vehicles, and the determination of transport properties under or near operating conditions is therefore important. We demonstrate that in situ 7Li NMR imaging in a battery electrolyte can directly capture the concentration gradients that arise when current is applied. From these, the salt diffusivity and Li + transport number are obtained within an electrochemical transport model. Because of the temporal, spatial, and chemical resolution it can provide, NMR imaging will be a versatile tool for evaluating electrochemical systems and methods.

Keyword
Electrolytes, Magnetic resonance imaging, Transport properties
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-103644 (URN)10.1021/ja305461j (DOI)000308574800006 ()2-s2.0-84866398560 (Scopus ID)
Funder
Swedish Research CouncilStandUp
Note

QC 20150624

Available from: 2012-10-18 Created: 2012-10-17 Last updated: 2017-12-07Bibliographically approved
2. Constant-time chemical-shift selective imaging
Open this publication in new window or tab >>Constant-time chemical-shift selective imaging
2013 (English)In: Journal of magnetic resonance, ISSN 1090-7807, E-ISSN 1096-0856, Vol. 226, 19-21 p.Article in journal (Refereed) Published
Abstract [en]

We demonstrate that chemical-shift-selective constant-time imaging (CTI) can be performed by simply inserting selective saturation into the original imaging pulse sequence. The performance of the proposed method is illustrated by 7Li CTI imaging in a battery model that contains both Li metal electrodes and an electrolyte containing a dissolved Li salt.

Keyword
Chemical shift imaging, Constant-time imaging, Selective saturation
National Category
Engineering and Technology
Identifiers
urn:nbn:se:kth:diva-117791 (URN)10.1016/j.jmr.2012.10.014 (DOI)000314190700003 ()2-s2.0-84870184644 (Scopus ID)
Funder
Swedish Research CouncilKnut and Alice Wallenberg Foundation
Note

QC 20130205

Available from: 2013-02-05 Created: 2013-02-05 Last updated: 2017-12-06Bibliographically approved
3. The protonation state and binding mode in a metal coordination complex from the charge measured in solution by electrophoretic NMR
Open this publication in new window or tab >>The protonation state and binding mode in a metal coordination complex from the charge measured in solution by electrophoretic NMR
2013 (English)In: Analytical Methods, ISSN 1759-9660, E-ISSN 1759-9679, Vol. 5, no 7, 1648-1651 p.Article in journal (Refereed) Published
Abstract [en]

We measured with high accuracy the effective charge of a uranium (VI)-AMP complex by electrophoretic NMR (eNMR). Using the same method, the degree of counterion association is also assessed which leads to a quantitative determination of the nominal charge which then provides the degree of ligand deprotonation in the complex. This demonstrates a new application of eNMR for resolving structural details of supramolecular complexes.

Keyword
Multinuclear Nmr, Stability-Constants, Uranyl Acetate, Ions, Polyelectrolytes, Nucleotides, Uranium, Cells
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-120562 (URN)10.1039/c3ay00023k (DOI)000316118500002 ()2-s2.0-84879538166 (Scopus ID)
Funder
Swedish Research Council
Note

QC 20130412

Available from: 2013-04-12 Created: 2013-04-11 Last updated: 2017-12-06Bibliographically approved
4. On electrophoretic NMR. Exploring high conductivity samples
Open this publication in new window or tab >>On electrophoretic NMR. Exploring high conductivity samples
2014 (English)In: Journal of magnetic resonance, ISSN 1090-7807, E-ISSN 1096-0856, Vol. 243, 17-24 p.Article in journal (Refereed) Published
Abstract [en]

The performance of a new electrophoretic NMR (eNMR) method that uses a Carr-Purcell-Meiboom-Gill echo train with repeated electric field reversal is investigated. We show that this pulse sequence, with acronym CPMGER, yields strongly reduced artifacts from convective flow effects caused by the simultaneous presence of electroosmotic and thermal driving forces. We demonstrate the achieved improvements in various aqueous solutions. Ultimately, the method can be used for obtaining electrophoretic mobilities by eNMR without relying on uncharged reference molecules, otherwise a significant limitation for electrophoretic experiments performed with nuclei other than 1H.

Keyword
CPMG, Double stimulated echo, Electroosmosis, eNMR, Sample cell, Thermal convection
National Category
Engineering and Technology
Identifiers
urn:nbn:se:kth:diva-145393 (URN)10.1016/j.jmr.2014.03.005 (DOI)000337121300003 ()2-s2.0-84898065953 (Scopus ID)
Funder
Swedish Research Council
Note

QC 20140519

Available from: 2014-05-19 Created: 2014-05-19 Last updated: 2017-12-05Bibliographically approved
5. Binding of monovalent and multivalent metal cations to polyethylene oxide in methanol probed by electrophoretic and diffusion NMR
Open this publication in new window or tab >>Binding of monovalent and multivalent metal cations to polyethylene oxide in methanol probed by electrophoretic and diffusion NMR
Show others...
2016 (English)In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 120, no 39, 10358-10366 p.Article in journal (Refereed) Published
Abstract [en]

Complex formation in methanol between monodisperse polyethylene oxide (PEO) and a large set of cations was studied by measuring the effective charge acquired by PEO upon complexation. Quantitative data were obtained at a low ionic strength of 2 mM (for some salts, also between 0.5 and 6 mM) by a combination of diffusion nuclear magnetic resonance (NMR) and electrophoretic NMR experiments. For strongly complexing cations, the magnitude of the acquired effective charge was on the order of 1 cation per 100 monomer units. For monovalent cations, the relative strength of binding varies as Na+ < K+ ≈ Rb+ ≈ Cs+, whereas Li+ exhibited no significant binding. All polyvalent cations bind very weakly, except for Ba2+ that exhibited strong binding. Anions do not bind, as is shown by the lack of response to the chemical nature of anionic species (perchlorate, iodide, or acetate). Diffusion experiments directly show that the acetate anion with monovalent cations does not associate with PEO. Considering all cations, we find that the observed binding does not follow any Hofmeister order. Instead, binding occurs below a critical surface charge density, which indicates that the degree of complexation is defined by the solvation shell. A large solvation shell prevents the binding of most multivalent ions.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2016
National Category
Chemical Sciences
Research subject
Chemistry
Identifiers
urn:nbn:se:kth:diva-149550 (URN)10.1021/acs.jpcb.6b08923 (DOI)000384959200019 ()2-s2.0-84990235162 (Scopus ID)
Funder
Swedish Research Council
Note

QC 20161116

Available from: 2014-08-22 Created: 2014-08-22 Last updated: 2017-12-05Bibliographically approved
6. Binding modes of cations to polyethylene oxide: An NMR study
Open this publication in new window or tab >>Binding modes of cations to polyethylene oxide: An NMR study
(English)Manuscript (preprint) (Other academic)
National Category
Chemical Sciences
Research subject
Chemistry
Identifiers
urn:nbn:se:kth:diva-149549 (URN)
Funder
Swedish Research Council
Note

QS 2014

Available from: 2014-08-22 Created: 2014-08-22 Last updated: 2017-02-16Bibliographically approved
7. Ion association in aqueous and non-aqueous solutions probed by diffusion and electrophoretic NMR
Open this publication in new window or tab >>Ion association in aqueous and non-aqueous solutions probed by diffusion and electrophoretic NMR
Show others...
(English)Manuscript (preprint) (Other academic)
National Category
Natural Sciences
Research subject
Chemistry
Identifiers
urn:nbn:se:kth:diva-149551 (URN)
Funder
Swedish Research Council
Note

QS 2014

Available from: 2014-08-22 Created: 2014-08-22 Last updated: 2014-08-25Bibliographically approved

Open Access in DiVA

Thesis, MarianneGiesecke(947 kB)369 downloads
File information
File name FULLTEXT01.pdfFile size 947 kBChecksum SHA-512
b887f6870745e72f908761db7fea9c54eb0f3dda2f525180823a0fe2768dd7348b8f3a5ab9469416445825d7927aa98072b9ee5e70cc7cccb94cb68b978db941
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Giesecke, Marianne
By organisation
Applied Physical Chemistry
Natural Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 369 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: 588 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