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Abstract
Surface functionalization treatments can be used to reduce the moisture sensitivity of cellulosic materials, which is particularly relevant for textile and packaging applications. One such approach is to use enzymatic methods to link plant-based lipids to cellulose surfaces. Structure-function relationship studies have shown evidence of long-chain fatty acids (C10–C18) introducing hydrophobic character with water contact angles > 90⁰ [1,2]. Here, we investigate the hydrophobicity introduced to cellulose with short to long-chain fatty acid esterification using molecular dynamics simulations [3]. We develop software tools for building models of functionalized cellulose microfibrils and surfaces, and use the models to study how fatty acid grafting affects the surface structure, the organization of interfacial water and water cellulose work of adhesion.
Our simulations show distinct structural effects due to the fatty acid carbon tails aggregating near the substitution sites on the hydrophilic cellulose surfaces. The degree of substitution and carbon tail length both influence the structure of the interfacial water, and medium to long chain fatty acids tend to form a patchy surface with variable water accessibility. Analysis of hydrogen bond density shows the formation of a depletion layer near the grafted surfaces. The water contact angle, as determined through the cellulose-water work of adhesion, shows a linear response to the graft chain length for C4–C12 side chains. After this, the contact area and work of adhesion between water and cellulose remain unchanged, reaching contact angle saturation for long-chain fatty acids. Such computational approach has potential use in the development and optimization of surface modification treatments for lignocellulosic materials.
Our simulations show distinct structural effects due to the fatty acid carbon tails aggregating near the substitution sites on the hydrophilic cellulose surfaces. The degree of substitution and carbon tail length both influence the structure of the interfacial water, and medium to long chain fatty acids tend to form a patchy surface with variable water accessibility. Analysis of hydrogen bond density shows the formation of a depletion layer near the grafted surfaces. The water contact angle, as determined through the cellulose-water work of adhesion, shows a linear response to the graft chain length for C4–C12 side chains. After this, the contact area and work of adhesion between water and cellulose remain unchanged, reaching contact angle saturation for long-chain fatty acids. Such computational approach has potential use in the development and optimization of surface modification treatments for lignocellulosic materials.
Original language | English |
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Number of pages | 1 |
Publication status | Published - 11 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 |
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Country/Territory | Sweden |
City | Gothenburg |
Period | 10/09/24 → 12/09/24 |
Internet address |
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Dive into the research topics of 'Wettability of fatty acid esterified cellulose surfaces from molecular simulations'. Together they form a unique fingerprint.Projects
- 1 Finished
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EnzyFunc: Enzyme-mediated attachment and detachment of multifunctional and biobased coating aided by digital material design
Koivula, A. (Participant)
Funded by the European Union, Funded by Research Council of Finland
1/01/22 → 31/12/24
Project: Academy of Finland project