The study of the elasticity of spider dragline silk with liquid crystal model

摘要

Spider dragline silk is an optimal biomaterial with a combination of high tensile strength and high elasticity,rnand it has long been suggested to belong to liquid crystalline materials. However, a satisfactory liquid crystalrndescription for the mechanical properties of the dragline is still missing.rnTo solve the long existing problem, we generalized the Maier-Saupe theory of nematics to construct a liquidrncrystal model of the deformation mechanism of the dragline silk.rnWe show that the remarkable elasticity of the dragline can be understood as the isotropic-nematic phaserntransition of the chain network with the beginning of the transition corresponding to the yield point. Therncalculated curve fits well with the measurements and the yield point is obtained self-consistently within ourrnframework. The present theory can also qualitatively account for the drop of stress in supercontracted spiderrnsilk. All these comprehensive agreements between theory and experiments strongly indicate the dragline tornbelong to liquid crystal materials.