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Visualizing the Cellulose Microfibrils Orientation
in Bamboo and Rattan by PLRS
Jianfeng Ma
Research Institute of Bamboo & Rattan Biomass New Materials, ICBR
“Plant Steel”
• A natural functionally-graded biocomposite material• Excellent load-bearing properties
Cellulose Biosynthesis and Assembly
Composition and structure according to function
Primary cell wall Cellulose fibrilsHemicelluloses Pectins
flexible and elastic
Secondary cell wall Cellulose fibrils HemicellulosesLignin
S1
primary wall
S2
S3
Middle lamellaLigninSmall amount of carbohydrates
Cellulose Biosynthesis and Assembly
Cosgrove., 2005, Nature Review.
Simon et al., 2018.
Hexameric particle rosettes
Cellulose synthase protein
Fiber Parenchyma
Bamboo Cellulose Nano-crystal
Samples P-CNC F-CNC
CrI (%) 50.86 54.87
Crystal size(nm)
2.17 2.08
Lattice distance (nm)
0.395 0.399
55% H2SO4
50°C , 1.0h
From Cellulose Chains to Microfibrils
Cellulose Chain Cellulose Nanocrystal Cellulose Microfibrils
Highly organized cellulose microfibrils
Disordered cellulose microfibrils
Mechanical Properties of Natural Cellulose
Young’s modulus is roughly 130 Gpa Tensile strength is close to 1 GPa
Gibbson, 2012. Journal of Royal Society Interface.
LM: El-Osta (1973, Mercury impregnation) ; Senft & Bendtsen (1985, , iodine impregnation)
PLM: Praynard (1954); Echolls (1955); Oldenburg (2007); Elbaum (2015)
XRD: Wardrop (1951); Watson & Dadswell (1964); Sahlberg (1997); Yang (2015)
SEM: Saka (1982); Westermark (1988); Xu (2006); Zheng (2017)
TEM: Leise (1956); Donaldson (1999); Singh (1999,2002); Fromm (2003); Ma (2015)
AFM: Cosgrove (2005, 2007, 2012, 2016) ; Ding (2012, 2014); Kafle (2014); Fei (2015)
SAXS/WAXS/SANS/WANS: Lichtenegger (1999) ; Jarvis (2015); Fei (2015)
FT-IR Microscopy: Schmidt (2006); Gierlinger (2007); Salmen (2011); Chang (2014)
Confocal Raman Microscopy: Atalla (1985, 1986); Gierlinger (2010); Xu (2015); Sun (2016)
SFG: Cosgrove & Kim (2017, 2018)
Cell Wall Imaging Techniques
Notburga Gierlinger. 2012, Journal of Experimental Botany.
Microfibrils Orientation
Electromagnetic Band
Ultravioletmicrospectrophotometry
Confocal laser scanning micro? scopy FT-IR microspectroscopy
Confocal Raman microspectroscopySpatial resolution=0.35 um
UMSP CLSM CRM FT-IR microspectroscopy
Jin et al., 2017, Spectra and Spectral analysis.
Raman Spectra from Lignocellulosic Biomass
Pinus
Poplar
M. sinensis
Bamboo
Rattan
Raman shift (cm-1)
Ram
an in
tensity (cts)
Wavenumbers
(cm-1) Component Assignment
2 945 Lignin C-H stretching in OCH3 asymmetric
2 897 Cellulose C-H and C-H2 stretching
1 655 Lignin Ring conjungated C=C stretching of coniferyl/sinapyl
alcohol; C=O stretching of coniferaldehyde/sinapaldehyde
1 600 Lignin Aryl ring stretching symmetric
1 464 Lignin and Cellulose HCH and HOC bending
1 423 Lignin O-CH3 deformation; CH2 scissoring; guaiacyl ring vibration
1 378 Cellulose HCC, HCO and HOC bending
1 330 Lignin? Aryl-OH or aryl-O-CH3 vibration?
1 274 Lignin Aryl-O of aryl-OH and aryl O-CH3; guaiacyl ring (with C=O
group) mode
1 173 Hydrocinnamic acids C-O stretching of Hca
1 140 Lignin? C-O-C stretching asymmetric?
1 122 Cellulose, Xylan, and
Glucomannan
Heavy atom (CC and CO) stretching
1 098 Cellulose Heavy atom (CC and CO) stretching
902 Cellulose Heavy atom (CC and CO) stretching
520 Cellulose some heavy atom str.
438 Cellulose some heavy atom str.
380 Cellulose some heavy atom str.
Peak Assignments
Atalla and Agarwal, 1986, Planta.
Evidence for orientation is detected through Raman intensity variation is detected from rotations of the exciting electric vector respect to cell wall geometry.
The cellulose pyranose rings of the anhydroglucose repeart units are in plane perpendicular to the cross section, while methine C-H bonds are in planes parallel to the cross
Cellulose Microfibrils Orientation
Polarized light
Cellulose chain
When the molecular vibrational direction are more parallel to the laser polarizationdirection the corresponding band intensity is enhanced.
Cellulose Microfibrils Orientation
Atalla and Agarwal., 1985, Science.
Atalla, et al., 1980, Macromolecules.
Polarized light direction
MFA
MFA
Raman images showing the MFA within the multilayer structure of thick walled bamboo fiber, 1080-1120 cm-1.
Mfs Orientation Bamboo Fiber Wall
Rattan Resources and Utilizaiton
Sheath Cane Seed
17
Bright view image (Left), overall morphology (Middle), lignin (blue) and cellulose (red) overlaid Raman image.
Cellulose (red), lignin (Middle) and overlaid Raman image.
Cellular Level Heterogeneity of components distribution
Polarized laser direction along the radial wall
Variation in Raman band intensity of broad and narrow wall layer.
Mfs Orientation Rattan Fiber Wall
C-O-C, 1095 cm-1
Mfs Orientation Rattan Fiber Wall
R= I1095/I2897
R: Vessel Secondary Wall>Fiber Narrow Layer >Fiber Broad Layer
An outermost primary wall composed of a meshwork of Mfs
The secondary wall containing Mfs mainly arranged in a parallel orientation
C-O-C CH,CH2
Mfs Orientation Rattan Vessel
Chanllenges
Fluorescence background
Spatial Resolution & Chemometrics
Quantitative analysis of cellulose microfibrils
orientation
Outlook
combination of Atomic force microscopy (AFM) +Raman
surface and materialproperties on the nanolevel
Molecular compositionon the microlevel+
II
(I) (II)
Acknowledgements
Funding:
National Key R&D Program of China (2017YFD0600804) National Natural Science Foundation of China (31500497)Fundamental Research Funds of ICBR (1632017014)
Group People :
Prof. Xinge LiuProf. Shumin YangDr. Genlin Tian Dr. Lili Shang
Jianfeng MaInternational Center for Bamboo and [email protected]+86-15101509897
Thanks a lot