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Informations
Publié par | johannes_gutenberg-universitat_mainz |
Publié le | 01 janvier 2010 |
Nombre de lectures | 12 |
Langue | English |
Poids de l'ouvrage | 3 Mo |
Extrait
Structure Formation as Studied by EPR
Spectroscopy: From Simple Solutions to
Nanoparticles
Dissertation
Zur Erlangung des Grades
„Doktor der Naturwissenschaften”
im Promotionsfach Chemie
am Fachbereich Chemie,
Pharmazie und Geowissenschaften
der Johannes Gutenberg‐Universität Mainz
von
Jeannine Heller
geboren in Fulda
Mainz, den 19. Mai 2010
Die vorliegende Arbeit wurde von November 2006 bis
Mai 2010 am Max‐Planck‐Institut für Polymer‐
forschung in Mainz angefertigt.
Dekan:
1. Berichterstatter:
2.
Tag der mündlichen Prüfung: 21.07.2010
Dedicated to Daniel
To every action there is always opposed an equal reaction.
~~~~
Sir Isaac Newton
1687
Contents
List of Symbols and Abbreviations
1 Introduction ...................................................................................................................... 9
2 Principles of Electron Paramagnetic Resonance Spectroscopy .................................... 13
2.1 Spin Hamiltonian Formalism ................................................................................... 14
2.2 Electron‐Zeeman Interaction 15
2.2.1 The Electron Spin in a Magnetic Field .............................................................. 15
2.2.2 g‐Anisotropy ..................................................................................................... 17
2.3 Zero‐field Splitting ................................................................................................... 20
2.4 Interactions with Nuclear Spins ............................................................................... 21
2.4.1 Nuclear Zeeman Interaction............................................................................. 21
2.4.2 Hyperfine Interaction ....................................................................................... 21
2.4.3 Nuclear Quadrupole Interaction ...................................................................... 24
2.5 Electron‐Electron Interactions ................................................................................. 25
2.5.1 Exchange Interaction ........................................................................................ 25
2.5.2 Dipolar ........................................................................................... 29
2.6 The Complete Spin Hamiltonian .............................................................................. 31
2.7 EPR of Nitroxide Radicals ......................................................................................... 32
2.7.1 Structure and Stability of Nitroxides ................................................................ 32
2.7.2 EPR of Nitroxides .............................................................................................. 34
2.7.3 Linewidths ........................................................................................................ 39
2.7.4 Rapid Anisotropic Motion about a Molecular Axis .......................................... 41
2.8 Numerical Simulation of EPR and ENDOR Spectra .................................................. 43
2.8.1 Dynamic Regimes in CW EPR ............................................................................ 44
2.9 Pulsed EPR Spectroscopy ......................................................................................... 50
2.9.1 Primary Electron Spin Echo (ESE) Experiment ................................................. 51
2.9.2 Relaxation Measurements ............................................................................... 52
2.9.3 Double Electron‐Electron Resonance (DEER) Spectroscopy ............................ 54
2.9.4 ENDOR Spectroscopy ....................................................................................... 563 The Solvation of Fremy’s Salt Studied with High‐Field Pulse ENDOR Spectroscopy ... 63
3.1 Introduction ............................................................................................................. 63
3.1.1 Motivation ........................................................................................................ 63
3.1.2 The Solvents Water, Methanol and their Mixtures ......................................... 65
3.2 Studied Systems ....................................................................................................... 67
3.3 High‐Field Pulsed Experiments ................................................................................ 70
3.3.1 Echo‐ Detected Measurements ........................................................................ 71
3.3.2 ENDOR Measurements ..................................................................................... 74
3.3.3 HYSCORE Measurements ................................................................................. 80
3.4 Molecular Dynamics Simulation .............................................................................. 81
3.5 Discussion ................................................................................................................ 83
3.6 Conclusion and Outlook........................................................................................... 87
4 Polyelectrolyte Solutions with Multivalent Salts .......................................................... 88
4.1 Polymers in Solution ................................................................................................ 88
4.1.1 Description of Polymer Shape in Solution ........................................................ 89
4.1.2 Polylelectrolytes in Solution ............................................................................. 93
4.1.2.1 Poisson‐Boltzmann Theory ........................................................................... 93
4.1.2.2 Debye‐Hückel Approximation ...................................................................... 94
4.1.2.3 Counterion Condensation ............................................................................ 95
4.2 Studied Systems ....................................................................................................... 96
4.3 DEER Measurements: Influence of Solvent and Ionic Strength .............................. 98
5 Characterization of Structure and Dynamics of Miniemulsions ................................. 101
5.1 Motivation ............................................................................................................. 101
5.2 Introduction .........................................................