Introduction –ss-NMR of inorganic systems NMR ... · PDF file NMR crystallography ss-NMR...

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Transcript of Introduction –ss-NMR of inorganic systems NMR ... · PDF file NMR crystallography ss-NMR...

  • 1

    Structural characterization of inorganic aluminosilicate systems:

    role of water

    (4)(4)

    +1

    +3 +2

    0 −1 −2 −3

    t1 τ 90°-sel.

    +1

    +3 +2

    0 −1 −2 −3

    t1 τ 90°-sel.

    Introduction – ss-NMR of inorganic systems NMR crystallography Problem of quadrupolar nuclei Removing of quadrupolar broadening (DOR, MQ/MAS) Enhancement of spectral resolution

    Structure of aluminosilicate systems Amorphous aluminosilicate inorganic polymers (AIP) – synthesis Primary structural data about Al/Si materials – 29Si a 27Al MAS NMR Amorphous-crystalline phase transition of AIPs How to get structural parameters

    29Si, 27Al, 23Na MAS NMR 27Al MQ/MAS NMR 1H MAS NMR and spin relaxation 29Si CP/MAS a REDOR NMR (localization of H2O) VA-CT 29Si CP/MAS (hydration extent) 1H-1H MAS (interaction network) 27Al REDOR MQ/MAS NMR Structural model

    Outlook

    Is NMR spectroscopy really such unique method?

    Magnetic Resonance Imaging

    Concept of NMR crystallography

    NMR crystallography

    ss-NMR Spectroscopy

    Molecular Modeling

    X-ray (Powder) Diffraction

    structural fragments

    process of structure refinement 1H-1H spin-exchange 1H-13C contacts 1H-15N distances

    motional frequencies

    motional amplitudes

    chemical shifts

    etc.

    diffraction pattern

    pair distribution function analysis

    etc.

    conformation (DFT)

    prediction of long-range arrangement

    NMR parameters (CASTEP)

    etc.

    Refined structure with incorporated segmental dynamics, intermolecular

    interaction and supramolecular architecture

    Applications

    Finding relations between molecular structure, and physicochemical properties (bioavailability) of…

    … pharmaceuticals based on solid solution and solid dispersions of API in polymer matrix,

    NMR active nuclei – problem of inorganic systems; I>1/2

    22 spins I=1/2 77 spins I=3/2, 5/2,9/2

    1 spin I=1

    Spin 1/2 Spin 3/2

    m=1/2

    m=-1/2

    m=-1/2

    m=1/2

    m=3/2

    m=-3/2

    Spectrum: narrow signal 0,1-100 Hz

    Spectrum: broad signal 1000-100000 Hz

    ( ) ( )

    ( ) ( )3cos30cos35 8

    1 cos

    1cos3 2

    1 cos

    24 4

    2 2

    +−=

    −=

    θθθ

    θθ

    P

    P

    = 0

    =−7/18

    θ = 54.74° MAS narrows 2nd order broadening

    only by a factor 3 to 4

    Quadrupolar broadening

    = 0

    =−7/18

    θ = 54.74°

    = 0

    =−7/18

    θ = 54.74°

  • 2

    ( ) ( )

    ( ) ( )3cos30cos35 8

    1 cos

    1cos3 2

    1 cos

    24 4

    2 2

    +−=

    −=

    θθθ

    θθ

    P

    P

    = 0

    =−7/18

    θ = 54.74°

    Quadrupolar broadening and MAS (off-MAS)

    17O DAS crystobalit

    DAS: Dynamic Angle Spinning

    ( ) ( )

    ( ) ( )3cos30cos35 8

    1 cos

    1cos3 2

    1 cos

    24 4

    2 2

    +−=

    −=

    θθθ

    θθ

    P

    P

    23Na DOR of sodium oxalate

    DOR: Double Rotation

    +1

    +3 +2

    0 −−−−1 −−−−2 −−−−3

    evolution mixing

    MQ SQ ST SQ CT

    z-filter “whole echo”

    t1 ττττ

    90°-sel.

    CT

    +1

    +3 +2

    0 −−−−1 −−−−2 −−−−3

    evolution mixing

    MQ SQ ST SQ CT

    z-filter “whole echo”

    t1 ττττ

    90°-sel.

    CT

    ppm

    -200 ppm 15

    10

    5

    0

    ppm

    20 0 ppm 15

    10

    5

    0

    23Na MQ/MAS Na2HPO4.H2O

    Multiple-quantum NMR spectroscopy

    ppm

    -40-30-20-1020 10 0 ppm

    -25

    -20

    -15

    -10

    -5

    35

    30

    25

    20

    15

    10

    5

    0

    SQ

    TQ

    A1, A4

    A3

    A2

    xx

    Kyanite, z-filtered experiment at 11.7 T

    anisotropic traces

    traces for A1 and A4 cannot be resolved

    27 kHz MAS frequency

    250 kHz RF

    excitation pulse: 1.9 µs conversion pulse: 0.7 µs 90° selective pulse: 11 µs

    Al-27 3Q MAS traces of Kyanite at different fields

    50 40 30 20 ppm 20 10 ppm40 30 20 10 ppm

    9.4 T 11.7 T 18.8 T

    1.0 1.0 1.0 0.8 1.0 0.8 0.7 1.02.0Int:

    27Al 3Q MAS of Kyanite at different fields

    Multiple-quantum NMR spectroscopy

    ppm

    -2020 0 ppm 15

    10

    5

    0

    23Na MQ/MAS

    Form III

    -20-100 ppm

    -2040 20 0 ppm

    23Na MAS NMR

    31P MAS NMR

    MQ/MAS NMR spectroscopy – polymorphism of ATP

  • 3

    -50 -100 ppm

    80 60 40 20 ppm

    27Al

    29Si

    Fly ash-slag-metakaoiline

    80 60 40 20 ppm

    -50 -100 ppm

    27Al

    29Si

    CSH gel

    80 60 40 20 ppm

    -50 -100 ppm

    Typical aluminosilicate inrognic polymer (AIP)

    27Al

    29Si

    ppm

    ppm -50 -100 ppm

    80 60 40 20 ppm

    Zeolite system

    27Al

    29Si

    27Al

    29Si

    80 60 40 20 ppm

    -50 -100 ppm

    Slightly crystalline AIP system

    Variability of Al/Si materials Synthesis of AIP systems

    Kaolin 650°C Metakaolin

    Al4(OH)8Si4O10

    1. Calcination

    activation @ RT

    Primary units2.Activation

    Si2O5.Al2O2

    Metakaolin Si2O5.Al2O2 + 5H2O+2NaOH

    Si

    OH

    OH OH

    OH

    Si

    OH

    OH OH

    OH Al

    -

    OH

    OH OH

    OH Na +

    Al -

    OH

    OH OH

    OH Na +

    polycondensation @ RT

    Primary building units

    3. Polycondensation

    Si

    OH

    OH OH

    OH

    Si

    OH

    OH OH

    OH Al

    -

    OH

    OH OH

    OH Na +

    Al -

    OH

    OH OH

    OH Na + Si

    OH

    O O

    OH

    Al -

    OH

    O OH

    Si

    OH O

    OH

    Al -

    OH OH

    Na +

    Na +

    OH2

    OH2

    OH2 OH2

    -4H2O

    Amorphous network

    Geopolymers and NMR, Davidovits: Geopolymers (1994)

    29Si MAS NMR

    Structure of AIP systems

    Q4(4Al)

    Q4(3Al) Q4(2Al)

    Q4(1Al)

    Q4(0Al)

    SiO4 AlO4

    Q4(4Al)

    Q4(0Al)

    Q4(3Al)

    Q4(1Al)

    a)

    b)

    100 50 0 ppm

    Al (IV) Al (V) Al (VI)

    Simple calcination: formation of metakaoline

    7days @ RT &

    1day @ 140°C; HT

    27Al MAS NMR

    Al (V) ssb

    -100-50 ppm

    1day @ RT

    7days @ RT

    177day @ RT

    7days @ RT &

    1day @ 100°C; HT

    Q4(0Al)

    Q4(1Al)

    Q4(2Al)

    Q4(4Al)

    Q4(3Al)

    Q0/Q1

    (OH)

    29Si MAS NMR

    Calcination with NaOH: formation of geopolymer precursor

    H yd

    ro th

    e rm

    a l tr

    e a tm

    e n t

    N o rm

    a l cu

    ri n g

    C a lc

    in a ti o n

    H yd

    ro th

    e rm

    a l tr

    e a tm

    e n t

    N o rm

    a l cu

    ri n g

    C a lc

    in a ti o n

    Si-O-

    D. Koloušek, J. Brus et al. JOURNAL OF MATERIALS SCIENCE 42 (22): 9267-9275 NOV 2007.

    Synthesis of AIP systems

    Method A Method B

    NT/7 d

    HT/7 d

    HT/14 d

    HT/21 d

    HT/28 d

    0

    10

    20

    30

    40

    50

    60

    70

    S tr

    en gh

    t, M

    P a

    Experimental conditions

    Stable

    system

    Unstable

    system

    Time dependence of compression strength

    (artificial aging)

    Stable

    system

    Unstable

    system

    Structural instability of AIPs: spontaneous crystallization

    Stable system

    Unstable system

    Basis structural parameters: 29Si,27Al,23Na MAS NMR

    Untreated AIPs Stable system

    Unstable system

  • 4

    Basis structural parameters: 29Si,27Al,23Na MAS NMR

    Artificially aged AIPs Stable system

    Unstable system

    Basis structural parameters: 27Al MQ/MAS NMR

    AIPs before and after accelerated aging Stable system

    Unstable system

    Basis structural parameters : 1H MAS NMR, relaxation

    1,00E-03

    1,00E-02

    1,00E-01

    1,00E+00

    1,00E-11 1,00E-10 1,00E-09 1,00E-08 1,00E-07 1,00E-06

    log(τc), s

    lo g

    (T 1 )

    , s

    • •

    ○ ○

    ■ ■

    □ □

    310 K

    280 K

    System A

    System B

    A-aged

    B-aged

    Fast motions Slow motions

    AIPs before and after accelerated aging Stable system

    Unstable system

    Hydration of star clusters Q4(nAl)

    System A System B

    Q4(3Al);22%

    Q4(2Al);25%

    Q4(1Al);10% Q4(4Al);42%

    ppm -140-130-120-110-100-90-80-70-60

    A aged B aged

    Q4(4Al);34%

    Q4(3Al);32%

    Q4(2Al);22%

    Q4(1Al);12%

    ppm -140-130-120-110-100-90-80-70-60

    Q4(4Al);33%

    Q4(3Al);28%

    Q4(2Al);27%

    Q4(1Al);8%

    ppm -140-130-120-110-100-90-80-70-60