Molecular dynamics for linear polymer melts in bulk and confined systems under shear flow.

摘要: In this work, we analyzed the individual chain dynamics for linear polymer melts under shear flow bulk and confined systems using atomistic nonequilibrium molecular simulations of unentangled (C50H102) slightly entangled (C178H358) polyethylene melts. While a certain similarity appears dynamic mechanisms chains in response to imposed field, interfacial near boundary solid walls system are significantly different from corresponding dynamics. Detailed molecular-level analysis motions wide range strengths carried out characterize intrinsic three regimes (weak, intermediate, strong). These essentially underlie various macroscopic structural rheological properties systems, such as mean-square end-to-end distance, probability distribution viscosity, first normal stress coefficient. Further based on mesoscopic Brightness method provides additional information about association with their mechanisms.