Molecular deformation of single spruce wood fibres followed by Raman microscopy

Notburga Gierlinger, Michaela Eder and Ingo Burgert

Johannes Kepler University LinzInstitute of Polymer Science

Max-Planck Institute of Colloids and InterfacesDepartment of Biomaterials

AIM AND APPROACH

AIM…changes on the molecular level during

- tensing

- changing „environment“

better understanding of the micromechanics

and cell wall polymer properties

Raman microscopy

tensile testing of wood tissues and single fibres

+APPROACH

SIR CHANDRASEKHARA VENKATA RAMAN

Rayleigh Scatter (elastic, same wavelength as incident light) Raman Scatter (inelastic, new wavelength)

RAMAN EFFECT

RAMAN- and IR- spectroscopy

IR Rayleigh Stokes Anti-Stokes hυ1

RAMAN

0

1

Virtual

hυ0 h(υ0-υ1) h(υ0+υ1)

ABSORPTION SCATTERING

change in dipolmoment change in polarisability

ground state

excited state

100015002000250030003500

Raman

FT-IR

cm-1

Abs

orba

nce

Ram

anIn

tens

ity

OH

CH

arom C-C, C-O

RAMAN- and IR- spectroscopywood spectra

wavenumber [cm-1]

4006008001000120014001600

Ram

an In

tens

ity [C

CD

cts

]

0

1000

2000

3000

4000

1657

1600

1457

1377

1339

1272

1122

1095

997 898

437378

517

1416 330499

458

Effect of orientation on Raman band intensity of wood spectra

latewood single fibre (MFA<10°)

Gierlinger, N; Luss, S.; König, Ch.; Konnerth, J.; Eder, M.; Fratzl, P. 2009 Cellulose microfibril orientation of Picea abies and its variability on the micron-level determined by Raman imaging. Journal of Experimental Botany: in print

red = 0, 3, 6, 9°pink = 12, 15, 18, 21 °turkis = 24, 27, 30, 33°blue = 36, 39, 42, 45°light green= 48, 51, 54, 57°green = 60, 63, 66, 69°grey = 72, 75, 78, 81°black = 84, 87, 90, 93°

y= y0+ax+bx2 R2 Std Err y0 a b PRESS

1122/1095 0.9918

0.0335 3.507 -5.602 2.208 0.0727

1377/1095 0.9961

0.0229 2.1324 -4.6192 2.4624 0.0341

378/1095 0.9942

0.0281 1.654 -3.084 1.445 0.0517

Prediction of cellulose orientation by band height ratios

Gierlinger, N; Luss, S.; König, Ch.; Konnerth, J.; Eder, M.; Fratzl, P. 2009 Cellulose microfibril orientation of Picea abies and its variability on the micron-level determined by Raman imaging. Journal of Experimental Botany: in print

factor R2

(CAL)

R2

(CV)RMSECV R2

(TS)RMSEP

3 0.999 0.999 0.0087 0.999 0.0098

1 0.998 0.998 0.0147 0.998 0.0148

Prediction of cellulose orientation by PLS models

Gierlinger, N; Luss, S.; König, Ch.; Konnerth, J.; Eder, M.; Fratzl, P. 2009 Cellulose microfibril orientation of Picea abies and its variability on the micron-level determined by Raman imaging. Journal of Experimental Botany: in print

sample layer MFAx-ray

1377/1095

1122/1095

378/1095

PLS_3 PLS_1 mean

S2 rad 0 1.79 9.9 11.76 10.79 6.86

S2 tang 0 1.34 9.41 10.41 6.64 5.56

S1 tang 36.80 48.88 50.05 50.06 47.12 46.58

S1 rad 34.03 47.95 52.78 51.99 47.50 46.85

S2 tang 20 14.06 24.40 26.34 27.66 26.79 23.85

S1 tang - 41.05 54.66 60.15 54.43 52.58 52.57

S2 tang 35 32.80 37.26 37.17 41.73 41.36 38.06

S1 tang - 39.13 49.52 53.33 54.89 52.18 49.80

S2 tang 50 30.21 40.34 49.37 49.29 48.28 43.51

S1 tang - 32.81 64.98 63.84 67.60 65.24 58.90

compression wood (CW)

opposite wood (OW)

latewood(LW20)

-

0latewood(LW00)

Prediction of cellulose orientation by Raman compared to X-ray

Gierlinger, N; Luss, S.; König, Ch.; Konnerth, J.; Eder, M.; Fratzl, P. 2009 Cellulose microfibril orientation of Picea abies and its variability on the micron-level determined by Raman imaging. Journal of Experimental Botany: in print

3375

wavenumber [cm-1]

120014001600320034003600

Ram

an In

tens

ity [C

CD

cts

]

6000

8000

10000

120001602A

3375

1097

OH

C-C, C-O

low and high stress level)

cellulose

arom. aryl str. lignin

Effect of tensile load on the Raman spectra

Gierlinger, N.; Schwanninger, M.; Reinecke, A.; Burgert, I. 2006: Molecular changes during tensile deformation of single wood fibers followed by Raman microscopy. Biomacromolecules, 7 (7): 2077-2081

wavenumber [cm-1]

106010801100112011401160

Ram

an In

tens

ity [C

CD

cts

]

6000

7000

8000

9000

10000

1124

10971092

1127

B

low and high stress level)

Effect of tensile load on the Raman spectra

Gierlinger, N.; Schwanninger, M.; Reinecke, A.; Burgert, I. 2006: Molecular changes during tensile deformation of single wood fibers followed by Raman microscopy. Biomacromolecules, 7 (7): 2077-2081

Position and Intensity of the Raman bandsis influenced by

• Composition of the sample (lignin, cellulose, hemicelluloses, extractives)

• Orientation of the molecules within the sample in respect to the laser polarisation direcetion

• Status (load) and environment (Dry wet) of the sample

Raman microscopy

tensile testing of wood tissues and single fibres

+APPROACH

Stress and reorientation on the molecular level

motorload cell

water reservoirfibre

TENSILE TESTER

SPRUCE LATEWOOD: tissue vs single fibre

SPRUCE LATEWOOD: tissue vs single fibre

Gierlinger, N., Burgert, I. 2006: Secondary cell wall polymers studied by Confocal Raman microscopy: Spatial distribution, orientation and molecular deformation. New Zealand Journal of Forestry Science, 36 (1): 60-71

SINGLE SPRUCE FIBRES adult and juvenile latewood

adult juvenile

strain [-]0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07

stre

ss [G

Pa]

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

MFA~5 MFA~15

strain [-]0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07

wav

enum

ber [

cm-1

]

1088

1090

1092

1094

1096

1098

1100latewoodjuvenile wood

b[0] = 1098.24b[1] = -210.16r ² = 0.97

b[0] = 1097.53b[1] = -128.93r ² = 0.95

stress [GPa]0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4

wav

enum

ber [

cm-1

]

1088

1090

1092

1094

1096

1098

1100latewoodjuvenile wood

b[0] = 1098.06b[1] = -7.71r ² = 0.98

b[0] = 1097.68b[1] = -8.20r ² = 0.95

SINGLE SPRUCE FIBRES adult and juvenile latewood

strain [ ]

0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07

stre

ss [G

Pa]

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

LW21JW05_005

JW5

adult latewood juvenile latewood

EW1

adult earlywood juvenile earlywood

MFA~15MFA~5

SINGLE SPRUCE FIBRES adult and juvenile - earlywood and latewood

strain [-]0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07

wav

enum

ber [

cm-1

]

1088

1090

1092

1094

1096

1098

1100adult earlyadult latejuv latejuv early

stress [GPa]0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4

wav

enum

ber [

cm-1

]

1088

1090

1092

1094

1096

1098

1100adult earlyadult latejuv latejuv early

SINGLE SPRUCE FIBRES adult and juvenile - earlywood and latewood

juvenile

adult

latewood

earlywood

MFA Geometry?

SINGLE SPRUCE FIBRES juvenile latewood: dry-wet

time [s]0 200 400 600 800

forc

e [m

N]

0

20

40

60

80

100

wav

enum

ber [

cm-1

]

1086

1088

1090

1092

1094

1096

H20

STOP STOPTENS TENS TENS

SINGLE SPRUCE FIBRES juvenile latewood: dry-wet

time [s]0 200 400 600 800

forc

e [m

N]

0

20

40

60

80

100

wav

enum

ber [

cm-1

]1086

1088

1090

1092

1094

1096

H20

STOP STOPTENS TENS TENS

time [s]0 200 400 600 800

forc

e [m

N]

0

20

40

60

80

100

MFA

[°]

0

10

20

30

40

H20

STOP STOPTENS TENS TENS

cellulose load microfibril orientation

CONCLUSIONS

• Much higher shifts (loads) in single fibre than in woodtissues

• Molecular cellulose load correlates across different samples (juvenile, adult, tissue, fibre) with macroscopicstress….except earlywood

• Wetting of the fibre: Load release through swelling induced change in orientation?

• Monitoring changes in molecular load and orientation simultaneously

THANKS

Biomaterial group (MPI Golm)

.......and you for your ATTENTION

Financial support:Max Planck SocietyAustrian Academy of Sciences(APART programme)

Peter Fratzl

Ingo BurgertMichaela Eder

INTITUTE OF POLYMER SCIENCE(Head: Prof. Sabine Hild)

Polymeric materials

• Flow characteristics rheology

• Solidification characteristics crystallization

• Microstructural characterization with respect to material properties

Biological materials

• Microstructure, local chemical composition and mechanical properties

• Mineralized tissues, plant cell wall

• microtomy, light microscopy• Raman-microscopy combined with AFM (PFM)• AFM, nanointendation• Extruder, Spin coater, DSC, Rheometer

Raman AFM

cotton linter cotton linter

strain0.00 0.01 0.02 0.03 0.04 0.05 0.06

shift

[cm

-1]

-5

0

5

10

15

20

25

1411cm 1381cm 1095cm 997cm 896cm 459cm 380cm 3378cm

OH str

strain-0.01 0.00 0.01 0.02 0.03 0.04 0.05 0.06

shift

[cm

-1]

-6

-5

-4

-3

-2

-1

0

1

1411cm (HCC, HCO, HOC bending)1095cm (COC) glycosid459cm (CCO) ring 380cm (CCC) ring

change in the hydrogen network

strain []0.00 0.01 0.02 0.03 0.04 0.05 0.06

stre

ss [G

Pa]

0.0

0.1

0.2

0.3

0.4

0.5

0.6

wav

enum

ber [

cm-1

}

1092

1093

1094

1095

1096

1097

change in load distribution

change in stress strain curve

gliding of fibrils

Samples under loadRAMIE single fibre

0/0 (parallel)90/900/9090/0

Polymer composition and orientation in plant fibres

RAMIE

Polymer composition and orientation in plant fibres

Depolarisation ratiosR1 = I(0/90)/I(0/0) = 0.07

R2 = I(90/0)/I(90/90) = 0.53

R1 = 0.19R2 = 0.2

0/0 90/900/9090/0

Ramie fiber

Bacterial cellulose film

Order parameters P2 and P4

Probable orientation distribution function

1096

MOLECULAR DEFORMATION IN WOOD STUDIED BY RAMAN MICROSCOPY

Wiley and Atalla (1987) Agarwal and Ralph (1997)