1

Part 2

Solid State NMR

2

Solid state NMR and polymer

Usage:

T2

Entanglement

Conductive polymer

Spin diffusion

Basic of 2D NMR and 2DWISE

Part 2

Molecular dynamics is ubiquitous and plays an

important role in the function of proteins, nucleic acids,

synthetic polymers, and other macromolecules. Nuclear

magnetic resonance (NMR) spectroscopy is a powerful

tool for investigating the detailed local motions in

molecules. Traditionally, NMR spectroscopy yields

dynamics information from relaxation time

measurements and from 2H line shape analysis. The

latter is particularly sensitive to the amplitude, geometry,

and time scales of motions.

Motion frequencies of molecules / Hz

T1, T2, NOE

Dipolar spectrum of 2H

Spectrum of CSA

2D exchange spectrum

刚性固体

液体 半刚性

凝胶

弛豫时间与分子运动 相关时间的关系

弛豫与分子运动

6

T1 verse T2

The spin lattice relaxation times (T1) of

polymers, primarily related to the local environment

of the nuclei, are sensitive to the high frequency

motions in large regions of polymers, while the

spin-spin relaxation (T2) are sensitive to the slower

relative translational motion and the low frequency

motion of a polymer chain.

7

T2

The T2 spin-spin relaxation curves obtained by pulsed NMR techniques can readily be used to study important feature of macromolecular systems quite distant from their chemical structure. Such features refer to more physical properties such as molecular size, flexibility and mobility, entanglement ( whose life time is comparable or longer than the period of measurements), the influence of solvent and temperature on this motion( which is related to viscosity), crystalline and the rate of crystallization, polymerization, and other chemical reactions where there is a considerable change in dimension etc.

8

Research of Compatibility

detection

parameter

relative

domain size

1HT1r 2~3nm

T1 20~30nm

T2

Spin diffusion 1~100nm

9

10

Using T2 to determining polymer mobility

The decaying signal of the transverse

magnetization M(t) is empirically following the

Weibull function:

Where a is the shape parameter, 1≤a≤2, M(t)

could be disposed to the soft domain (a=1), and

rigid domain(a=2)

])(1

exp[)(2

0

a

T

t

aMtM

11

The f s and f l values are the fractional amount of

short T2(T2s) and long T2(T2

l) components, which

are related to the polymer-rich and polymer-poor

phases in sample.

)()(2

1exp)(

2

2

2 B

OB

A

OAT

tM

T

tMtM

%100])(

[

%100])(

[

tM

Mf

tM

Mf

OBl

OAS

12

Gel of PVC/DOA :

(a)、 T2 and f as a function of Mw (C=5%)

(b)、 T2 and f as a function of Concentration

(Mw=50×104g/mol)

13

Freeze dried gel of PVC/DOA :

(a)、 T2 and f as a function of Mw (C=5%)

(b)、 T2 and f as a function of Concentration

(Mw=50×104)

14

Gel (Mw of

PVC:50×104g/mol)

T2 and f as a function of

concentration for (a) PVC/THF

and PVC/MOR (b) PVC/DOA

15

Physical absorbing on carbonblack[2]

16

Amorphous parts between PVC crystallite

T2p: observed plateau value at (TgNMR+150oC)

T2rl: T2 value for a rigid chain below Tg

a: coefficient, which has a value of about 6.2 for aliphatic chain

Z:the number of statistical segments between cross-links

Mu: molar mass per elementary chain unit

n: the number of rotatable backbones in an elementary chain unit

C∞: the number of ratatable backbone bands of the statistical segment

111

22

)()()(

/

)(

entamorphentamorph

uc

rlp

NNN

nMZCM

ZTaT

17

T(oC) Namorph+ent Namorph

160 32 48

180 35 54

18

Entanglement

Entanglement and disentanglement

are reversible dynamic processes

which take place above the glass

transition temperature Tg.

19

Concentrated Solution

Determined by T1:

T1l and T1s are the long and short relaxation times of spin lattice relaxation, respectively. The short and long relaxations correspond to the motion of entangled and free chain segment, respectively.

1

)exp()exp(21)(

)(

11

sl

s

s

l

l

PP

T

tP

T

tP

M

tM

20

PS in Bulk

Basic Principle: time-domain(TD) NMR

Fourier

transformation

HO–CH2–CH3

frequency

spectrum

coupling N

S

spin

free induction decay

acquisition time

…encoded in time-

domain signal decay

inhom. low field:

•no spectral resolution

•coupling: additional broadening

Adapted from Kay’s presentation.

22

低场NMR

Magic-sandwich echo (MSE)

What can we do with TD NMR?

Component Analysis—FID analysis

Molecular Dynamics—FID analysis

Network Structures, entanglement and

crosslink--DQNMR

FID fitting

Generally, for the fully recovered FID, its decay could be described as:

2

2 2int 2( ) exp( ( / ) ) exp( ( / ) ) exp( ( / ) )i mv v

r rigid i ermediate m mobilef t f t T f t T f t T

with 1r i mf f f 2 2int 2rigid ermediate mobileT T T

Note: The T2 values we obtained here are not the “true T2”. Instead, it is usually

called as “the apparent T2”. The “true T2” should be obtained through another

experiments, such as Hahn-echo or CPMG.

Empirically, T2rigid~20us,

T2intermediate=30us~100us

T2mobile~0.1ms

Kerstin Schäler, Ph.D thesis, MLU. 2012

Solid State Nucl. Magn. Reson. 2008, 34, 125

Macromol. Chem. Phys. 2006, 207, 1150

Reliability of FID fitting

Criteria:

1.The reliability of the proposed model

2.The smooth variation of fr,fi,fm as a function of

temperature

3.The unreliability of other model

(two components VS three components)

26 Macromolecules 2006, 39, 6653-6660.

混和@ 26 oC

陈化@ 26 oC

陈化@ 50 oC

2D纳米受限界面

Macromolecules 2005, 38, 4030

Carboxyl-terminated 1,4-polybutadien

27

组分的定量分析

完全重聚的CTPB/C18-clay纳米复合物的1H NMR FID

28

组分的定量分析

Weibull 方程和指数方程

A(t)=A0[frigidexp(-t/T2,rigid)a+finterexp(-t/T2,inter)+fmobileexp(-t/T2,mobile)]

Litvinov, V. M. et.al. Macromolecules 2011, 44, 4887.

29 Saalwaechter, K., et al. Journal of Chemical Physics 2003, 119, 3468.

双量子(DQ) NMR

分子运动特征时间与自相关函数之间的关系

1H DQ 五脉冲序列.

30

静态条件下的双量子实验

60

Wang, M. F.; Bertmer, M.; Demco, D. E.;

Blumich, B.; Litvinov, V. M.; Barthel, H.,

Macromolecules 2003, 36, 4411.

CTPB/C18-clay的双量子建立曲线

32

高分子-粘土相互作用效应:

Saturated Unsaturated

第一个极值峰位置与高分子浓度之间的关系

Gao, Y.; Zhang, R. C.; Lv, W. F.; Liu, Q. J.; Wang, X. L.*; Sun, P. C.;

Winter, H. H.; Xue, G., J. Phys. Chem. C 2014, 118, 5606.

(1) Polymer orientation

(2) polymer motion

(3) Entanglement

Deuterium NMR of synthetic polymers

Macromolecules 1991, 24, 398-402

39

2D NMR

Basic concept

),(

),(

),(

),(),(

21

211

2121

2121

11

2211

S

tSedt

ttsedtedt

Stts

ti

titi

40

Plot

1、Stacked trace plot 2、Contour plot

41

Solid State HETCOR

A 1H –13C heteronuclear chemical shift correlation (HETCOR) experiment for solid-state materials.

Analogous to solution-state HETCOR experiments, this sequence provides correlation between 1H and 13C chemical shifts. This experiment differs from the solution-state HETCOR in that correlation depends on dipolar interactions rather than J coupling.

Provide a new approach of obtaining the 1H CRAMPS spectrum in F1 dimension without doing CRAMPS experiment.

42

43

Caravatti, P.; Neuenschwander, P.; Ernst, R. R.,

Characterization of heterogeneous polymer blends

by two-dimensional proton spin diffusion

spectroscopy. Macromolecules 1985, 18, 119-122.

44

2D WISE (wideline separation)

It allows for the correlation of mobility and

structure in organic solid. Difference of molecular

dynamics are probed by 1H wideline shapes, which

are separated in the second dimension by 13C

chemical shifts. With a mixing time inserted before

cross polarization from 1H to 13C, 1H spin diffusion

allows one to determine the mobility at interfaces

and to measure domain size approximately.

45

(a)、Conventional 1H wideline spectrum of a blend of

polystyrene (PS) and poly(vinyl methylether) (PVME)

(b)、2D 1H/13C WISE NMR spectrum indicating different

mobilities of the two components

46

Separated local field (SLF)

The dipole-dipole coupling, for instance

between 1H-13C, or 1H and 15N, provides

valuable structure information.

Since the dipolar couplings corresponding to

the local fields, such experiments are often

named ‘separated local field’

0 1

2 22

3

2

1 0

(1 3cos )(3 )

1(1 3cos ) (3 )

2

z x

ij zi zj i j

i j ij

eff z ij zi zj i j

i j

eff

H h I H I

I I I Ir

H I B I I I I

wherein

H iH kh

53

J. Phys. Chem. B

2002, 106, 7355-7364

54

Reference:

1、 A.Charlesby analysis of macromolecular structures by pulsed NMR Raidat. Phys. Chem. Vol.39,No.1,pp.45-51 1992

2、 V.M.Litvinov and P.A.M. Steeman EPMD-Carbon Black Interactions and the Reinforcement Mechanisms, As studied by Low-Resolution 1H NMR Macromolecules 1999, 32, pp.8476-8490

3、Po-Da Hong, Hsing-Tsai Huang Effect of polymer-solvent interaction on gelation of polyvinyl chloride solution European Polymer Journal 35(1999) pp.2155-2164

4、Po-Da Hong and Jean-Hong Chen Network structure and chain mobility of freeze-dried polyvinyl chloride/dioxane gels Polymer Vol.39 pp.5809-5817 1998

5、Barendswaard, W., V.M.Litvinov, et al.Crystallinity and Microstructure of Plasticized Poly(vinyl chloride). A 13C and 1H Solid State NMR Study. Macromolecules 1999 32: 167-180.

55

6、 Shizhen Mao, Shaoru Ni, Youru Du and Lianfang Shen Entangled network formation in concentrated solutions of 1,2-polybutadiene by 13C NMR relaxation study Polymer Vol.36 pp.3409-3411, 1995 7、 A.Charlesby, E.M.Jaroszkiewicz, Entanglement and Network Formation in Polystyrene Eur.Polym.J. 1985, Vol.21, pp:55-64

8、S.Kaplan, E.M. Conwell, A.F.Richter, and A.G. MacDiarmid Solid-State 13C NMR Characterization of Polyanilines J. Am. Chen. Soc 1988, 110, pp.7647-7651

9、K. Schmidt-Rohr and H.W.Spiess Multidimensional solid-state NMR and polymers academic press 1994

10、Mellinger, F., M. Wilhelm, et al. Calibration of H-1 NMR spin diffusion coefficients for mobile polymers through transverse relaxation measurements Macromolecules 1999 32(14): 4686-4691.

56

11、 H.W.Spiess, Structure and Dynamics of Solid Polymers

from 2D- and 3D-NMR Chem.Rev. 1991, 91, pp:1321-

1338

12、 P.Caravatti, J.A.Deli, et al. Direct Evidence of

Microscopic Homogeneity in Disordered Solids

J.Am.Chem.Soc. 1982 104: 5506-5507.

13、K.Schmid-Rohr, J.Clauss, and H.W.Spiess Correlation

of Structure, Mobility, and Morphological Information in

Heterogeneous Polymer Materials by Two-Dimensional

Wideline-Separation NMR Spectroscopy

Macromolecules, 1992, 25, pp.3273-3277