All-cellulose composites based on microfibrillated
cellulose and filter paper via a NaOH-urea solvent
system: supporting information
Benoît Duchemin a,*, Déborah Le Corre b,1, Nolwenn Leray b, Alain Dufresne c,
Mark Staiger b
a
LOMC, UMR 6294 CNRS-Université du Havre, Normandie Université, 53 rue Prony, 76058
Le Havre, France
b
MacDiarmid Institute for Advanced Materials and Nanotechnology, Department of
Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch 8140,
New Zealand
c
Laboratoire Génie des procédés papetiers, Institut National Polytechnique de Grenoble
(EFPG-INPG) BP65, 38402 Saint-Martin d’Hères Cedex, France
1
Present address: Plant and food research, Canterbury Agriculture & Science Centre, Gerald
St, Lincoln, 7608, New Zealand
* Corresponding author. Tel : +33235217154 ; fax : +33235217198
Email address: benoit.duchemin@univ-lehavre.fr (B. Duchemin).
XRD
The samples were analysed in the transmission mode using a “gonio scan” (-) on a
Pan’alytical X’pert powder diffractometer equipped with a CoK source at 40 kV and 40
mA with λ = 1.7902 Å. Programmable anti-scatter slits had a fixed aperture of ½°
whereas the anti-diffusion slits had a fixed aperture of 1°. The detector was a linear
Pix’cel 1D detector. The scan was performed in the 5-50° range in steps of 0.013° (118
s/step). The samples (1 layer) were stacked between two kapton foils. A kapton
background was measured and substracted from all the curves. The curves were then area
normalized. All curves were rescaled at the copper wavelength (λ = 1.5418 Å) according
to Bragg’s law.
FP
20
min
40
min
80
min
3h
12h
10
15
20
25
2. (°)
30
35
40
Figure S1. Diffractograms of filter paper before (top) and after various dissolution times (below).
MFC
20
min
40
min
80
min
3h
12h
10
15
20
25
30
35
40
2. (°)
Figure S2. Diffractograms of microfibrillated cellulose before (top) and after various dissolution times (below).
A method using a successive simulation of powder diffractograms and the
measurement of their relative amorphous/cellulose I/cellulose II amount in the signal thanks
to a least square procedure was used (Nam et al. 2016). This method has the advantage of
taking into account the signal of the severely overlapped peaks of weaker intensities. This part
of the signal is often erroneously included as part of the amorphous content when simple peak
fitting procedures are used. As a consequence, the crystallinity measured using this method is
closer to the true crystallinity of the specimens, as measured using other more complex
methods such as the Rietveld method. In comparison to the Rietveld method, this method has
the benefit of being relatively operator-insensitive. The small number of parameters adjusted
during the least-square fitting also means that the method is fast, simple and can be applied to
poorly crystalline samples which contain a mixture of cellulose I and cellulose II.
10
20
30
40
50
10
20
30
40
50
10
20
30
40
50
10
20
30
40
50
10
20
30
40
50
10
20
30
40
50
Figure S3. Simulated diffractograms of ACC using modeled powder diffractograms and a semi-empirical
background. FP (left) and MFC (right) after 0 (top; only cellulose I), 20 min (middle; mixture of cellulose I and
II) and 40 min (bottom; only cellulose II) long dissolutions.
It was also possible to simulate diffractograms of cellulose I using the assumptions of various FWHM for a
range of crystallite sizes ranging from extremely thick crystallites to thin crystallites with only two chains
stacked together in the direction perpendicular to the (200) plane. This simulation demonstrated that the
maximum of the measured diffractograms was shifted to lower values solely on the effect of peak broadening
and independently of the lattice parameters. The crystallite width was calculated using Scherrer equation
assuming a peak centered at the diffractograms maximum, an artifact that will be dealt with in detail in a
subsequent publication.
90
80
23
70
22.9
60
22.8
50
22.7
40
30
22.6
20
22.5
Crystallite width d (Å)
Diffractogram maximum (°)
23.1
10
22.4
0
0
2
4
6
8
10
12
FWHM (°)
Figure S4. Variation of the diffractograms maximum (blue)) and measured crystallite width (red) as a function of
the FWHM parameter as set in Mercury.
ATR-FTIR
All measurements were performed on a Perkin-Elmer “Frontier” spectrometer equipped
with an Attenuated Total Reflectance accessory. The scans were accumulated from eight
passes with a resolution of 2 cm-1 in the 4000-650 cm-1 range. Each spectrum is the average of
three measurements at three different locations. Calculations of the total crystallinity index
(TCI) was performed from the ratio of the absorption peaks 1372/2900 cm-1 (Nelson 1964;
Carillo 2004). These two peaks were chosen because of their low susceptibility to water (C-H
bending at 1372 cm-1, and C-H or CH2 stretching at 2900 cm-1). Contrary to Segal’s method in
XRD, this method is applicable for both cellulose I and II. The strongest band of the three
bands at 2900 cm-1 was chosen.
Figure S5. Transmittance data of filter paper (a) and microfibrillated cellulose (b) as obtained after dissolution
times of 3 h (top) and 12 h (bottom).
Table S1. TCI of the cellulose substrates after various dissolution times.
Dissolution
0
80 min
3h
12 h
FP
0,95
0,79
0,49
0,53
MFC
0,66
/
0,73
0,73
time
Mechanical testing
The toughness of the composites was also assessed by measuring the area under the stressstrain curve from the start of the tensile test until the specimens were fractured. These values
are comparable to those of common synthetic materials used for packaging.
FP
3
MFC
Toughness (MJ.m-3)
2.5
2
1.5
1
0.5
0
0
20
40
80
Dissolution time (min)
Figure S6. Toughness of the composites after various dissolution times.