| Abstract Scope |
Coconut endocarp features a unique combination of superior properties including low weight, high strength, high hardness, and high toughness, although these properties are usually mutually exclusive in synthesized composites. However, it remains unclear of the microstructure-property relationship that is responsible for its outstanding performance. In this study, we performed both all-atom molecular dynamic and coarse-grained molecular dynamic simulations to explore valuable insights into the nanoscale strengthening and toughening mechanisms of coconut endocarp. Our simulation results show that the interactions between cellulose-hemicellulose and cellulose-lignin are the strongest and weakest ones, respectively. Hydrogen bonding is revealed to play a key role in determining the interfacial strength. Thereafter, we built a brick-and-mortar structure of coconut endocarp consisting of cellulose, hemicellulose, and lignin. Uniaxial tension simulations were carried out. Interesting deformation and failure phenomena, including negative Poisson’s ratio of voids, voids expansion, and coalescence, were observed to explain the strengthening and toughening mechanisms. |