Study On The Collective Dynamics Properties Of Self-propelled Nanomotors In Active Complex Media

Self-propelled micro-/nanomotor is a kind of micro-/nanoscale self-assembly device that can convert chemical energy,light energy,thermal energy and other energy into kinetic energy and realize autonomous movement.In recent years,the micro-/nanomotor has developed rapidly and Researchers make some achievements in drug target transport,biological sensing,water quality monitoring,environmental remediation and self-assembly.Since the environment provides “self-propelled energy”,the impact of the research environment on motor dynamics is of particular importance.In view of the fact that the actual environment of a motor is a chemical-activated non-equilibrium system,it is clear that its impact is more complicated.But so far,few study is about this area.In this paper,mesoscopic simulation method is used for two parts of the study: the complicated spatial-temporal changing environment,and the collective dynamics of the motor under the interaction.There are mainly the experiment and numerical simulation methods for the micro-/nanomotor research.Computer numerical simulation is not limited to the constraints of the experimental conditions and thus it is a convenient and efficient research methods.In the second chapter,We introduce several commonly used numerical simulation methods firstly,such as the Monte Carlo method.Then we detail the multiparticle collision dynamics(MPC)method,which is a particle-based mesoscopic simulation method.The MPC method is to study the solution as a particle,the solution particle size reduction.We have a detailed derivation of the specific algorithms and properties in the MPC method.In the third chapter,the MPC-MD method is used to simulate the collective dynamics of a self-propel nanomotor(sphere-dimer motor)in a chemically oscillating medium.The collective dynamics of nanomotors of different numbers and sizes are studied in cosine function curve-shaped and zig-zag oscillation respectively.The total distance function among the different motor quantifying the collective structure of the moving motor.There are some interesting clusters in these oscillating environments with the addition and removal of fuel particles.The radial distribution function is used to discuss the specific configuration of these clusters and the average velocity is used to analyze the movement.In the fourth chapter,we study the dynamics of roll waves with time-delay that propagate in excitable media.We discuss the influence of increase the time-delay on the configuration and period of roll-wave.In addition we studied the influence that produced by diffusion coupling on delay-induced roll wave.Finally,the phase diagram of diffusion coupled time-delay plane is given.We believe the results in this work may shed light on the understanding the collective dynamics of motors in chemical active media.