Molecular Dynamic Simulation On Interaction Between Active Matter And Chain-like Macromolecule

Active matter is a class of emerging nonequilibrium material in recent years.The material is concerned by the scientific community because of its deep physical intension,novel phenomenon and a wide range of application prospects.The class of material covers not only bacteria,fish and birds and other biological groups,but also covers a variety of artificial active colloidal particles.This thesis focuses on the interesting and novel behaviors of chain-like polymeric molecules in the active Brownian particle baths.In this thesis,we investigate the translocation of chain-like molecules under asymmetrical particle baths and the molecular evolution of configuration in the active particle bath with hydrodynamic interaction.And then the study promotes us to understand the motion characteristics of the active particles under soft boundary conditions.This study is closely related to the transport behavior of various biological macromolecules in life,and also provides reference for future research and design of intelligent materials and molecular drug carriers.Firstly,in the first two chapters,we present the current research progress and the molecular dynamics simulation methods used in this paper.In the third chapter,we study the translocation behavior of chain-like molecules in the cavity containing two classes of different particles,active particle and its passive alternative.We characterize the relationship between the probability of translocation and the time and relative parameters of the active particles.Furthermore,the translocation mechanism of chain-like molecules is analyzed by calculating the force,configuration of the molecules and density distribution of the active particles.We propose that at low density,the active particles are accumulated around the chain molecule.The accumulation leads to the chain-like molecules pass into the cavity containing active particles.At high density,the active particles form a structure of living crystal around the boundary of cavity.This structure makes the chain-like molecules form channels in their own path.We find that the translocation of the chain molecules at this situation is mainly toward the side of the equilibrium particles.In the fourth chapter,we study the change of conformational and kinetic properties of chain-like molecules in the active particle bath with hydrodynamic interaction.We compare the scaling law with the behavior in the equilibrium particle bath.The mean square end distance,the mean square radius of gyration and the mean square displacement of the centroid are also investigated.We present the effect of active particles on the behavior of chain molecules under poor solvent.Finally,we summarize and forecast the subject in last chapter.