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ecular Dynamics Investigation of Capturing Paracrystalline Cellulose Phase
from Mixed Crystalline and Amorphous Cellulose Under Constant Load
Veerapandian Ponnuchamy1, Jakub Sandak1,2, Anna Sandak1,3
1 InnoRenew CoE, veerapandian.ponnuchamy@innorenew.eu, jakub.sandak@innorenew.eu, anna.sandak@innorenew.eu
2 University of Primorska, Andrej Marušič Institute
3 University of Primorska, Faculty of Mathematics, Natural Sciences and Information Technologies
Cellulose is one of the major abundant biopolymers on earth, roughly half of all plants are
constituted from it. It is composed of linearly dispersed glucose polymers that are strongly
bonded through hydrogen bonds. Two distinct phases of cellulose can be seen in a typical
wood, namely crystalline and amorphous region. The ratio of crystalline and amorphous
region controls the typical properties such as rigidity and flexibility of the cellulose fibers. The
mechanical properties of the cellulose depend on the amount of crystallinity and organization
of both phases. Moreover, combined crystalline and amorphous have not been analyzed in detail
and no systematic study exists on the investigation of paracrystalline phase formation under
constant load conditions. The investigation of paracrystalline’s structural morphology, hydrogen
bond information and mechanical properties are thus necessary for understanding microfibril at
molecular level. To address these issues, we employ molecular dynamics simulations to study
of the formation of paracrystalline states under constant load. GROMACS was used for all MD
simulations with GROMOS 53a6 force field. The system is composed of a mixture of crystalline
cellulose plates and amorphous cellulose. Each crystalline cellulose plate is comprised of 30
glucose chains, with each chain containing 18 glucose units and each amorphous contains four
glucose chains with 518 units. The amorphous region is confined between two plates. The upper
crystalline plate is fixed, and the bottom plate is loading with different forces, for instance,
1000, 3000, 5000, 7000 kJ mol-1 nm-2. The radial distribution function (RDF) demonstrates
that the obtained long range ordering for paracrystalline lies between that of corresponding
amorphous and crystalline peaks (Kulasinski et al., 2014). The RDF peak intensity increases
at increasing load. Therefore, paracrystalline state is predominant and also inevitable at the
crystal and amorphous interphase.
Keywords: molecular dynamics, cellulose, paracrystalline state, constant load, amorphous
Acknowledgements: The authors gratefully acknowledge the European Commission for funding
the InnoRenew project (Grant Agreement #739574) under the H2020 Widespread-Teaming
programme and the Republic of Slovenia for funds from the European Regional Development
Fund.
REFERENCE
Kulasinski, K., Keten, S., Churakov, S.V., Derome, D., Carmeliet J., 2014. A comparative molec-ular dynamics study
of crystalline, paracrystalline and amorphous states of cellulose. Cellulose. 21(3), 1103-16. https://link.springer.com/
article/10.1007/s10570-014-0213-7
INNORENEW COE INTERNATIONAL CONFERENCE 2020
22
from Mixed Crystalline and Amorphous Cellulose Under Constant Load
Veerapandian Ponnuchamy1, Jakub Sandak1,2, Anna Sandak1,3
1 InnoRenew CoE, veerapandian.ponnuchamy@innorenew.eu, jakub.sandak@innorenew.eu, anna.sandak@innorenew.eu
2 University of Primorska, Andrej Marušič Institute
3 University of Primorska, Faculty of Mathematics, Natural Sciences and Information Technologies
Cellulose is one of the major abundant biopolymers on earth, roughly half of all plants are
constituted from it. It is composed of linearly dispersed glucose polymers that are strongly
bonded through hydrogen bonds. Two distinct phases of cellulose can be seen in a typical
wood, namely crystalline and amorphous region. The ratio of crystalline and amorphous
region controls the typical properties such as rigidity and flexibility of the cellulose fibers. The
mechanical properties of the cellulose depend on the amount of crystallinity and organization
of both phases. Moreover, combined crystalline and amorphous have not been analyzed in detail
and no systematic study exists on the investigation of paracrystalline phase formation under
constant load conditions. The investigation of paracrystalline’s structural morphology, hydrogen
bond information and mechanical properties are thus necessary for understanding microfibril at
molecular level. To address these issues, we employ molecular dynamics simulations to study
of the formation of paracrystalline states under constant load. GROMACS was used for all MD
simulations with GROMOS 53a6 force field. The system is composed of a mixture of crystalline
cellulose plates and amorphous cellulose. Each crystalline cellulose plate is comprised of 30
glucose chains, with each chain containing 18 glucose units and each amorphous contains four
glucose chains with 518 units. The amorphous region is confined between two plates. The upper
crystalline plate is fixed, and the bottom plate is loading with different forces, for instance,
1000, 3000, 5000, 7000 kJ mol-1 nm-2. The radial distribution function (RDF) demonstrates
that the obtained long range ordering for paracrystalline lies between that of corresponding
amorphous and crystalline peaks (Kulasinski et al., 2014). The RDF peak intensity increases
at increasing load. Therefore, paracrystalline state is predominant and also inevitable at the
crystal and amorphous interphase.
Keywords: molecular dynamics, cellulose, paracrystalline state, constant load, amorphous
Acknowledgements: The authors gratefully acknowledge the European Commission for funding
the InnoRenew project (Grant Agreement #739574) under the H2020 Widespread-Teaming
programme and the Republic of Slovenia for funds from the European Regional Development
Fund.
REFERENCE
Kulasinski, K., Keten, S., Churakov, S.V., Derome, D., Carmeliet J., 2014. A comparative molec-ular dynamics study
of crystalline, paracrystalline and amorphous states of cellulose. Cellulose. 21(3), 1103-16. https://link.springer.com/
article/10.1007/s10570-014-0213-7
INNORENEW COE INTERNATIONAL CONFERENCE 2020
22
