Investigation of material properties by NMR in low and high magnetic fields [Elektronische Ressource] / vorgelegt von Doru Gabriel Rata

Prof Blümich

Sujets

• Physik

Informations

• Publié par: rheinisch-westfalischen_technischen_hochschule_-rwth-_aachen
• Publié le: 01 janvier 2006
• Nombre de lectures: 47
• Langue: Deutsch
• Poids de l'ouvrage: 6 Mo

Extrait

INVESTIGATION OF MATERIAL
PROPERTIES BY NMR IN LOW AND
HIGH MAGNETIC FIELDS







RATA DORU GABRIEL




Investigation of Material Properties by
NMR in Low and High Magnetic Fields








Von der Fakultät für Mathematik, Informatik und Naturwissenschaften der Rheinisch-
Westfälischen Technischen Hochschule Aachen zur Erlangung des akademischen
Grades eines Doktors der Naturwissenschaften genehmigte Dissertation

vorgelegt
von
Dipl. Phys. Rata Doru Gabriel
aus Targu Jiu (Romania)

Berichter: Universitätsprofessor Dr. rer. nat. Bernhard Blümich
Universitätsprofessor Dr. Dan E. Demco


Tag der mündlichen Prüfung: 10. Juli 2006



Diese Dissertation ist auf den Internetseiten der Hochschulbibliothek online
verfügbar.


If we knew what it was we were doing, it would not be called research, would it?

Albert Einstein
Contents

1. Introduction and Motivation..................................................................................... 1
2 Basic NMR Relaxometry and Diffusiometry............................................................. 4
2.1 Resonance phenomenon ................................................................................ 4
2.2 Relaxation in NMR experiments...................................................................... 5
2.2.1 Introduction ............................................................................................. 5
2.2.2 Limits and definition for transverse relaxation......................................... 8
2.2.3 Irreversibility and spin-system size ......................................................... 9
2.2.4 Irreversibility and molecular motion....................................................... 10
2.2.5 Classification of transverse relaxation................................................... 10
2.3 Diffusion ........................................................................................................ 11
2.3.1 Free diffusion ........................................................................................ 11
2.3.2 Restricted diffusion ............................................................................... 14
2.4 Spin diffusion. Domain sizes and internuclear distances from spin diffusion
and dipolar couplings..................................................................................... 21
2.4.1 Introduction ........................................................................................... 21
2.4.2 Proton spin diffusion ............................................................................. 22
2.4.3 Proton experiments principles and 1D spectra...................................... 22
12.4.4 Analysis of H spin-diffusion data.......................................................... 24
2.4.5 Initial rate, interfacial area, and domain sizes ....................................... 25
3. Material Characterization by the NMR-MOUSE.................................................... 30
3.1 A mobile NMR device for measurement of porosity and pore size distribution
of drilled core samples................................................................................... 30
3.1.1 Introduction ........................................................................................... 30
3.1.2 Construction of the Halbach scanner 32
3.1.3 Application of the Halbach scanner to measurements of porosity and
pore size distributions in geological drill core samples........................... 36
3.1.4 Summary and conclusions.................................................................... 38
3.2 Self-diffusion measurements by a mobile single-sided NMR sensor with
improved magnetic field gradient ................................................................... 39
3.2.1. Introduction .......................................................................................... 39
3.2.2. Experimental........................................................................................ 41
3.2.3 Results and discussion ......................................................................... 44 II
3.2.4 Conclusions .......................................................................................... 51
®
3.3 NMR-MOUSE sensor for online detection in chemical extraction................ 53
3.3.1 Introduction and motivation................................................................... 53
3.3.2 NMR methods and samples.................................................................. 54
3.3.3 Results and discussions ....................................................................... 54
3.3.4 Conclusion ............................................................................................ 56
3.4 Applications to stone ..................................................................................... 57
3.4.1 Investigation of stones from Japan ....................................................... 57
3.4.2 Stone conservation ............................................................................... 60
4. Material Characterization by High-Field NMR 67
4.1 Self-diffusion anisotropy of small penetrant molecules in deformed elastomers
....................................................................................................................... 67
4.1.1 Introduction ........................................................................................... 67
4.1.2 Free-volume treatment of diffusion ....................................................... 68
4.1.3 Diffusion anisotropy .............................................................................. 70
4.1.4 Experimental section............................................................................. 72
4.1.5 NMR measurements 73
4.1.5 Results and discussion ......................................................................... 74
4.1.7 Conclusions .......................................................................................... 80
15 Investigation of the Thermal Ageing in Polyamide 4,6 by H Transverse
Magnetization Relaxation and Spin-Diffusion NMR .................................................. 82
5.1 Introduction ................................................................................................... 82
5.2 Experimental section..................................................................................... 84
5.2.1. Materials .............................................................................................. 84
5.2.2. DSC measurements............................................................................. 84
5.2.3 Proton NMR measurements.................................................................. 86
5.3 Results and discussions................................................................................ 88
5.3.1 Phase composition and segmental dynamics from the line widths ....... 88
5.3.2 Double-quantum dipolar filter................................................................ 90
5.3.3 Proton spin diffusivities ......................................................................... 92
15.3.4 Dominant morphology established by H spin-diffusion ........................ 93
5.3.5 Effective domain sizes ........................................................................... 98
5.4 Conclusions................................................................................................... 99
6 General Conclusions ............................................................................................100

III
Appendices..............................................................................................................102
Apendix A: Restricted diffusion ..........................................................................102
References ..............................................................................................................105
















IV

List of abbreviations and symbols

AFM atomic force microscopy
AW Anderson/Weiss formalism
B static magnetic field 0
BWR Bloch/Wangsness/Redfield theory
Cm matching capacity
Ct tuning capacity
CPMG Carr-Purcell-Meiboon-Gill
D self diffusion coefficient
D(t) apparent diffusion coefficient
DQ double quantum
DSC differential scanning calorimetry
E* effective energy per mole
FID free induction decay
G magnetic field gradient
IODP Integrated Ocean Drilling Program
L the diffusion length scale D
®MOUSE Mobile Universal Surface Explorer (registered mark of RWTH-Aachen)
NMR Nuclear Magnetic Resonance
NR natural rubber
PA46 polyamide 4,6
PCB printed circuit board
PDMS poly(dimethylsiloxane)
PE polyethylene
PFG pulse field gradient
PVAC poly(vinyl acetate)
q reciprocal space
R universal gas constant
RF radio frequency
S/V Surface to volume ratio

V
SANS small-angle neutron scattering
SAXS small-angle X-ray scattering
SEM scanning electron microscopy
SGSE steady gradient spin ec