The NMR of solid polymer: an overview

Part 1NMRNMR

from liquid to solidfrom liquid to solid

2

Liquid NMRLiquid NMR

High solution NMR refer to liquid NMR whose

line width are less than 1 Hzline width are less than 1 Hz.

This spectrum affords considerable information

concerning structure, composition,

microstructure, conformation, defects, branching,

and in some cases number average molecularand in some cases, number-average molecular

weights of synthetic polymer

3

A nuclear magnetic moment μ in H0

a)relationship between two frames4

a)relationship between two framesb)movement of μ in rotating frame

MagnetizationMagnetization

N

i

iM i

Larmor frequence

0H 0Pulse angle

tHPulse angle

5ptH1

Relaxation

Bl h i Bloch equation0MMdM ZZ

1

Md

dMTdt

2Tdt

)1(01eMM

t

Tt

Z

111max

2eMM Tt

6"1

'11

222 TTT

7

弛豫与分子运动

凝胶凝胶

刚性固体刚性固体

半刚性液体

半刚性弛豫时间与分子运动

相关时间的关系

Determination of T1Determination of T1

Inversion recovery：(180o，τ，90o，acq）

9

10

Calculation of T11

0ZZ

TMM

ddM

1Tdt

)21( 1Tt

eMM

)21(0Z eMM

11

Determination of T22

Spin echo（90o，τ，180o， τ ，acq）q

)2( 2]

"2)2([

'0'

2

2

2)( Tt

Tt

y eeMtM

'2

2

T

twhen

'0'

2)( Ty eMtM

1212

CPMG

Sequence:（90ox’， ，180o

y’, 2 , 180oy’ ……）

Merit: eliminate the errors of dephasing and inexact pulse lengthp g

自旋回波测量T2弛豫时间自旋回波测量 2弛豫时间

13

It i f th k l f t i l i t t bli hIt is one of the key goals of material science to establish

structure-property relationships in order to improve known and

design new materials. This holds in particular for synthetic

polymers whose materials properties depend on both the molecularpolymers, whose materials properties depend on both the molecular

structure and the organization of the macromolecules in the solid

state: their phase structure, morphology, molecular order and

molecular dynamicsmolecular dynamics.

Flory, 1953; Kroschwitz, 1990

14

Therefore, experimental techniques like solid state NMR

are needed that can characterize the behavior of polymers

on a molecular level and on mesoscopic scales in order toon a molecular level and on mesoscopic scales in order to

relate it to the macroscopic properties.relate it to the macroscopic properties.

15

Solid State NMR

Suitable for the study of:Suitable for the study of:1. structure of unsolvable polymer p y2. conformation、crystallization and

morphology of solid state polymersmorphology of solid state polymers3. miscibility y4. domain size

16

Th H ilt i d th tThe Hamiltonian and the nature of spin interaction

H=Hext+Hint

Hext: interaction with external fieldH : interaction ith internal fieldHint: interaction with internal field

17

Hext=Hz+Hrf

Hz: Zeeman interaction with e ternal static magnetic field Bexternal static magnetic field B0

Hrf: Zeeman interaction with radio f fi ldfrequency field B1

Zeeman interactioninteraction

18

H =H +H +H +HQ+HS +HHint HD+Hcs+HJ+HQ+HSR+Hen

HD: dipolar interaction HD: dipolar interaction

HCS:chemical shift interaction

HJ: indirect dipolar interaction

HQ: quadrupole interaction for nuclei with I>1/2

HSR: spin-rotation interaction

H i i i f l i d l hi h Hen: spin interaction of nuclei and electrons which creates

the Knight shift in magnetic or conducting materials.19

the Knight shift in magnetic or conducting materials.

Dipolar interaction

In liquid，fast relative movement between nuclei makes the dipole-dipole

interaction reduced dramatically(line width less than10－4 gauss) In the solid theinteraction reduced dramatically(line width less than10 gauss). In the solid, the

relative movement is slow because nuclei are close to each other. So the dipole-

dipole interaction broaden the line width greatly(line width:10～20gauss).

2020

dipole interaction broaden the line width greatly(line width:10 20gauss).

Quadrupole interactionQuadrupole interaction

2 )(52 22 abZQ eN

1H 13C 2H 14N 33S 35Cl21

1H 13C 2H 14N 33S 35Cl

Pulse sequence designq g

Pulse sequence is the combination of pulses and delay

time between them To identify different magnetictime between them. To identify different magnetic

circumstance, different pulse sequence, which enhance

some interaction and eliminate others, is used to get

wanted signal. The mutual point of special pulse

sequence is the adding of evolution time (e) whichsequence is the adding of evolution time (e), which

permits selective interaction between spins.

22

DD（dipole decoupling)p p g)

Continuous high power irradiation on one spin species

eliminates the heteronuclear couplings to the other spin

species regardless of the states of the magnetizationsspecies, regardless of the states of the magnetizations.

It should be noted that, because of the natural dilution

of the 13C atoms, homonuclear dipolar coupling

between two 13C nuclei can be neglected.

23

Chemical shift anisotropyChemical shift anisotropy

24

MSAMSA(magic spin angle)

)"""(31' 33221133

1

)(3

2

33221133

)"2"")(cos31(61

3322112

25

MAS with different spin speedMAS with different spin speed

26

CP(cross polarization)( p )

HH condition (Hartmann-Hahn)

CHH CHH 131311

Enhancement factor: γ1H/γ13C≈4 Merit the recycle delays and thus the Merit： the recycle delays, and thus the

measuring times are reduced due to the shorter T 1H rather than T 13CT1

1H, rather than T113C.

27

28

Efficiency of dipole-dipole relaxationEfficiency of dipole dipole relaxation

1 2 2 61H C H CH CDD N r

T

1T

γ:gyromagnetic ratio r: internuclear distance τ:molecular correlation time

29

Combination of DD, CP and MAS,

PMMA a、stationary b、DD/CP c、MAS/DD d、MAS/DD/CP

30

Reference:Reference:

1、薛奇 高分子结构研究中的光谱方法 高等教育出版社 1、薛奇 高分子结构研究中的光谱方法 高等教育出版社1995第一版

2、王金山 核磁共振波谱仪与实验技术 机械工业出版社第 版1982第一版

3、Tongyin Yu and Mingming Guo Recent developments in 13C solid state high resolution NMR ofdevelopments in 13C solid state high-resolution NMR of polymers Prog.Polym.Sci. Vol.15 pp:825-908 1990

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

5、Alan E. Tonelli NMR Spectroscopy and Polymer Mi t t Th C f ti l C ti AT&TMicrostructure: The Conformational Connection AT&T Bell Laboratories 1989

31

Part 2

Solid state NMR and polymer

Usage:Usage: T2 T2

Entanglement Conductive polymer

S i diff i Spin diffusion Basic of 2D NMR and 2DWISE

32

Basic of 2D NMR and 2DWISE

33

Research of Compatibilityp y

d t ti l tidetection parameter

relative domain size

1HT1 2~3nm

T1 20~30nm

T2

S i diff i 1 100Spin diffusion 1~100nm

34

35

T1 verse T21 ve se 2

The spin lattice relaxation times (T1) of

polymers primarily related to the local environmentpolymers, 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 frequencyrelative translational motion and the low frequency

motion of a polymer chain.

36

T22

The T2 spin-spin relaxation curves obtained by pulsedThe T2 spin spin relaxation curves obtained by pulsed NMR techniques can readily be used to study important feature of macromolecular systems quite distant from y qtheir chemical structure. Such features refer to more physical properties such as molecular size, flexibility and

bili l ( h lif i i blmobility, entanglement ( whose life time is comparable or longer than the period of measurements), the influence of solvent and temperature on this motion( which is relatedsolvent and temperature on this motion( which is related to viscosity), crystalline and the rate of crystallization, polymerization and other chemical reactions where therepolymerization, and other chemical reactions where there is a considerable change in dimension etc.

37

Pulse sequence to measure T2q 2

Solid-echo pulse sequence, SEPS(90ox-τ-90o

y-τ-acq)

with τ=20μs to record the magnetization of the lowwith τ 20μs to record the magnetization of the low

mobile fraction of the sample.

Hahn-echo pulse sequence, HEPS(90ox-τ’-180o

x-τ’-

acq) is used to measure T2 of the mobile region

only (τ’>50μs )only. (τ’>50μs )

38

Using T2 to determining polymer mobilityg 2 g p y y

The decaying signal of the transverse magnetization M(t) is empirically following the Weibull function:

])(1exp[)( 0a

Tt

aMtM

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

could be disposed to the soft domain (a=1), and rigid domain(a=2)

39

)()(1)( 2 tMtMM

)()(21exp)(

2

2

2 BOB

AOA T

tMT

tMtM

M %100])(

[ tM

Mf OAS

%100])(

[ tM

Mf OBl

The f s and f l values are the fractional amount of )(tM

short T2(T2s) and long T2(T2

l) components, which are related to the polymer-rich and polymer-poor

40

p y p y pphases in sample.

Gel of PVC/DOA :(a)、 T2 and f as a function of Mw (C=5%)

41

(a)、 T2 and f as a function of Mw (C 5%) (b)、 T2 and f as a function of Concentration (Mw=50×104g/mol)

F d i d l f PVC/DOAFreeze dried gel of PVC/DOA :(a)、 T2 and f as a function of Mw (C=5%) (b) T and f as a function of Concentration

42

(b)、 T2 and f as a function of Concentration (Mw=50×104)

Gel (Mw of PVC:50×104g/mol)PVC:50×104g/mol)T2 and f as a function of concentration for (a) PVC/THF

43

concentration for (a) PVC/THF and PVC/MOR (b) PVC/DOA

Physical absorbing on carbonblack[2]

44

Amorphous parts between PVC crystallite

22 )( rlp ZTaT 22

/ uc nMZCM111 )()()(

entamorphentamorph NNN

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

T rl: T2 value for a rigid chain below Tg T2 : 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 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

45

n: the number of rotatable backbones in an elementary chain unit C∞: the number of ratatable backbone bands of the statistical segment

T(oC) Namorph+ent Namorph

160 32 4846

160 32 48180 35 54

Entanglement g

Entanglement and disentanglement

are reversible dynamic processes

which take place above the glass

transition temperature Tg.

47

Concentrated Solution

Determined by T1:y 1

)exp()exp(21)(

sltPtPtM

1

)p()p()( 11

sl

ss

ll

PPTTM

T1l and T1s are the long and short relaxation times of spin lattice relaxation respectively The short and

sl

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

48

1 2 PB 20% in concentrated1,2-PB 20% in concentrated solution of deuterated benzene

Group T (s) P(%)-CH= slow 0.89 87

fast 0 003 13fast 0.003 13-CH2 slow 0.37 94

fast 0.002 6-CH- slow 0.67 88

fast 0.004 12

49

PS in Bulk

50

2D NMR2D NMR

Basic conceptp

),(),( 2121 Stts

),( 21212211 ttsedtedt titi

),( 21111 tSedt ti

),( 21 S

51

PlotPlot

1、Stacked trace plot 2、Contour plot1、Stacked trace plot 2、Contour plot

52

Example of 2D exchange NMRp g

53

2D WISE (wideline separation)( p )

It allo s for the correlation of mobilit andIt allows for the correlation of mobility and structure in organic solid. Difference of molecular dynamics are probed by 1H wideline shapes whichdynamics are probed by 1H wideline shapes, which are separated in the second dimension by 13C chemical shifts With a mixing time inserted beforechemical shifts. With a mixing time inserted before cross polarization from 1H to 13C, 1H spin diffusion allows one to determine the mobility at interfacesallows one to determine the mobility at interfaces and to measure domain size approximately.

54

(a) Conventional 1H wideline spectrum of a blend of(a)、Conventional H wideline spectrum of a blend of polystyrene (PS) and poly(vinyl methylether) (PVME)(b)、2D 1H/13C WISE NMR spectrum indicating different

55

( ) p gmobilities of the two components

56

Reference:1、 A.Charlesby analysis of macromolecular structures by pulsed

NMR R id t Ph Ch V l 39 N 1 45 51 1992NMR Raidat. Phys. Chem. Vol.39,No.1,pp.45-51 19922、 V.M.Litvinov and P.A.M. Steeman EPMD-Carbon Black

Interactions and the Reinforcement Mechanisms, As studied by , yLow-Resolution 1H NMR Macromolecules 1999, 32, pp.8476-8490

3、Po-Da Hong Hsing-Tsai Huang Effect of polymer-solvent3、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 P D H d J H Ch N t k t t d h i4、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.

57

y

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 Jaroszkiewiczpp.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 7647-7651Chen. 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

58

transverse relaxation measurements Macromolecules 1999 32(14): 4686-4691.

11、 H.W.Spiess, Structure and Dynamics of Solid Polymers from 2D and 3D NMR Chem Rev 1991 91 pp:1321from 2D- and 3D-NMR Chem.Rev. 1991, 91, pp:1321-1338

12 P Caravatti J A Deli et al Direct Evidence of12、 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 M l l 1992 25 3273 3277Macromolecules, 1992, 25, pp.3273-3277

59

Trends in Solid-State NMRTrends in Solid-State NMR* Towards Liquids Resolution

* Speeds is what counts in Solids!

Trend 1: High Field Resolution -> Probes (Decoupling)Sensitivity (Speed in Acquisition)

p

y ( p q )

Trend 2: Bio NMR Resolution, Low RF Heating (-> speed)

Trend 3: Fast MAS Resolution, Selectivity, SensitivityLiquids-like Techniques (e.g. Low Power)

Trend 4: Fast 2D Speed in Acquisition

Trend 5: Console Tech. Speed (Switching, Timing), Sensitivity,Cleanness, Resolution (Decoupling Performance)Performance)