Projects per year
Abstract
Carbon materials are important for our everyday life, as they are essential components in a range of products from electrical devices to fiber reinforced plastics. Currently used carbon materials are almost solely produced from non-renewable precursors, and there is a growing need for sustainable alternatives. One of the candidates is cellulose, which is both renewable and abundantly available. Unfortunately, cellulose-based carbon materials remain notably inferior to fossil-based ones, largely because carbon structure formation in cellulose pyrolysis is not adequately understood.
In our ongoing work, we study the chemical and structural pathways of cellulose carbonization using atomistic simulations based on the ReaxFF reactive force field. We both evaluate the capability of the method to reproduce known reactions and products of cellulose pyrolysis, and predict reactions that lead to amorphous condensed phase structures at early stages of the carbonization process. Our modelling work is linked to an experimental campaign to understand the transformation of cellulose into an intermediate thermostable condensed phase and ultimately carbon.
Our first modelling studies focus on the mechanism and kinetics of chain scission at high temperatures and heating rates, which are accessible using (unbiased) molecular dynamics (MD) simulations. Many of the predictions are compatible with mechanisms proposed for cellulose fast pyrolysis, but the absence of anhydrosugar forming reactions suggests that the high temperatures might hinder correspondence with practical conditions. To confirm that this is not a shortcoming of the force field, we are performing systematic force field evaluation for cellulose. Moreover, we study crosslinking reactions between cellulose chains at significantly lower temperatures using biased MD simulations. Simulations with cellulose only show no crosslinking, whereas cellulose and maltosan produce stable crosslinks, as does maltosan only. This suggests that levoglucosan end groups could play a role in the formation of an amorphous cross-linked network.
In our ongoing work, we study the chemical and structural pathways of cellulose carbonization using atomistic simulations based on the ReaxFF reactive force field. We both evaluate the capability of the method to reproduce known reactions and products of cellulose pyrolysis, and predict reactions that lead to amorphous condensed phase structures at early stages of the carbonization process. Our modelling work is linked to an experimental campaign to understand the transformation of cellulose into an intermediate thermostable condensed phase and ultimately carbon.
Our first modelling studies focus on the mechanism and kinetics of chain scission at high temperatures and heating rates, which are accessible using (unbiased) molecular dynamics (MD) simulations. Many of the predictions are compatible with mechanisms proposed for cellulose fast pyrolysis, but the absence of anhydrosugar forming reactions suggests that the high temperatures might hinder correspondence with practical conditions. To confirm that this is not a shortcoming of the force field, we are performing systematic force field evaluation for cellulose. Moreover, we study crosslinking reactions between cellulose chains at significantly lower temperatures using biased MD simulations. Simulations with cellulose only show no crosslinking, whereas cellulose and maltosan produce stable crosslinks, as does maltosan only. This suggests that levoglucosan end groups could play a role in the formation of an amorphous cross-linked network.
Original language | English |
---|---|
Number of pages | 1 |
Publication status | Published - 10 Sept 2024 |
MoE publication type | Not Eligible |
Event | FibRe International Conference 2024 - Chalmers University of Technology, Gothenburg, Sweden Duration: 10 Sept 2024 → 12 Sept 2024 https://fibre2024.treesearch.se/ |
Conference
Conference | FibRe International Conference 2024 |
---|---|
Country/Territory | Sweden |
City | Gothenburg |
Period | 10/09/24 → 12/09/24 |
Internet address |
Fingerprint
Dive into the research topics of 'Exploring cellulose carbonization pathways using reactive force field methods'. Together they form a unique fingerprint.Projects
- 1 Active
-
CelCarbo: Elucidation of the structural development during cellulose carbonization for advanced carbon materials
Vaari, J. (Participant)
1/09/22 → 31/08/26
Project: Academy of Finland project