Dynamic Simulation Of Active Colloidal Particle

For a long time,physics research has been devoted to exploring the most basic interactions between substances.It is believed that as long as we understand the interaction of the basic units of matter,we can perfectly and accurately reconstruct the world around us.However,people now gradually realize that this way of understanding and comprehending the combination of the world is impossible,because even in the simplest interaction,the huge number of motion units itself will produce many complex statistical phenomena.The basic method for studying multi-body interaction systems is statistical physics.Through nearly 200 years of development,statistical physics has achieved great success from gases,crystals and quantum statistics.Nevertheless,the problem that statistical physics can handle today is still only a small part of the natural world-an equilibrium system with a high degree of symmetry.However,the real world is unbalanced.For example,the system of life.From bacteria to vegetation,show us that there is more knowledge about non-equilibrium awaiting us to discover.In addition to living systems,there is also a class of non-equilibrium systems with very long relaxation times,such as granular systems and amorphous materials.For these systems,there is no complete theoretical framework to describe them.Therefore,developing new statistical physics methods to deal with multi-body interaction systems that are far from equilibrium is a frontier issue of modern physics.The work of our research group is to use colloids as a model system and try to explore the basic laws of non-equilibrium systems from a large number of statistical data.This article uses multi-particle collision dynamics and molecular dynamics to simulate the dynamic behavior of the colloidal system.The main purpose is to explore the dynamic behavior of the colloidal particles in the non-equilibrium state and to elucidate the microscopic motion mechanism.The first chapter introduces what is active colloidal particles and lays the foundation for careful exploration of the subject of this article.The second chapter is the method and theoretic model,focusing on the multi-particle collision dynamics method.This method is an efficient and accurate coarse-grained simulation method that can accurately describe the internal thermal turbulence,diffusion,dissipation and friction in the system.In the third chapter,the difference between the kinetic behavior of colloidal particles at the boundary wall of the system and the other positions of the system is introduced.For this reason,we design two systems,one is a colloidal particle system that absorbs heat under illumination.The other is an endothermic solvent system.By use molecular dynamics simulations,the reasons for this difference and the microscopic mechanisms were elucidated.The fourth chapter summarizes the relevant research results and prospects the prospect and direction of the active colloid system.