Theoretical Studies Of Interactions Between A Membrane And Nanoparticles

The interaction of nanoparticles with cell membranes has been a subject of active research due to its numerous applications in many areas of soft-matter and biologi-cal systems. With the rapid development of synthesis techniques, different types of nanoparticles can be made to achieve controlled functionalities. Theoretical studies between a membrane and nanoparticles have important applications for designing suit-able drug carriers and will help us to understand the process in the real biological situation.The Helfrich elastic model has been widely used in the current works which are related to the membranes. This model can well describe the geometrical deformation of the membrane from a macroscopic point of view. In this thesis, we theoretically stud-ied the interactions between membranes and various nanoparticles on the basis of the Helfrich elastic model. We found out how the properties of particles and membranes affect the interactions.Firstly, we studied the system of cylindrical particles adhering to an originally flat fluid membrane. Three situations are considered:one striated cylindrical particle, two pure cylindrical particles and two Janus cylindrical particles. The results depend on the patterns of the particles and appear a variety of steady-states for the sparse striated particles. While the results of the particles with dense stripe are same to that of the pure particles. We compared the adsorptive angle of a single cylindrical particle with that of two cylindrical particles under the same conditions. The adsorptive angle of two pure cylindrical particles can be bigger or smaller than the angle of a single particle which prove that two pure cylindrical particles can not only promote but also suppress their interactions with the membrane. But two Janus cylindrical particles can only suppress their interactions with the membrane. At the same time, we present the phase diagram for the system of two pure cylindrical particles.We also compared the differences of their interactions with the membrane be-tween the striated spherical particles and the pure spherical particles. The results of the sparse striated particles are different from that of the pure spherical particles. While the results between the dense striated particles and the pure spherical particles became similar. The particles with various stripes can be partially wrapped and totally wrapped by the membrane.