title: Effect of Acetyl Group on Mechanical Properties of Chitin/Chitosan Nanocrystal: A Molecular Dynamics Study.
abstract: Chitin fiber is the load-bearing component in natural chitin-based materials. In these materials, chitin is always partially deacetylated to different levels, leading to diverse material properties. In order to understand how the acetyl group enhances the fracture resistance capability of chitin fiber, we constructed atomistic models of chitin with varied acetylation degree and analyzed the hydrogen bonding pattern, fracture, and stress-strain behavior of these models. We notice that the acetyl group can contribute to the formation of hydrogen bonds that can stabilize the crystalline structure. In addition, it is found that the specimen with a higher acetylation degree presents a greater resistance against fracture. This study describes the role of the functional group, acetyl groups, in crystalline chitin. Such information could provide preliminary understanding of nanomaterials when similar functional groups are encountered.
authors.affiliation: Department of Architecture and Civil Engineering, City University of Hong Kong, Hong Kong, China. junhecui2-c@my.cityu.edu.hk.
authors.forename: Junhe
authors.initials: J
authors.lastname: Cui
authors.affiliation: Department of Architecture and Civil Engineering, City University of Hong Kong, Hong Kong, China. zechuanyu2-c@my.cityu.edu.hk.
authors.forename: Zechuan
authors.initials: Z
authors.lastname: Yu
authors.affiliation: Department of Architecture and Civil Engineering, City University of Hong Kong, Hong Kong, China. denvid@mit.edu.|Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. denvid@mit.edu.
authors.forename: Denvid
authors.initials: D
authors.lastname: Lau
mesh_terms: D000107:Acetylation; D002686:Chitin / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry*; D006244:Hardness; D006860:Hydrogen Bonding; D056004:Molecular Dynamics Simulation; D053758:Nanoparticles / Q000737:chemistry*
chemical_list: D002686:Chitin; D048271:Chitosan
keywords: acetyl group; chitin; chitosan; fracture energy; steered molecular dynamics (SMD) simulation; stiffness