Studies On Self-assembly And Conformational Behavior Of Polymer Nanofluids

Polymer fluid has become most researches' studying subject, it usually means thepolymer melt and the polymer solution. In the previous study, it has been proven thatsome configuration with great engineering features could be formed spontaneously bythe interaction of weak bonds among polymer molecules and other elements(nanotubes, nano particles and so on) in the composite containing amphiphilic blockmacromolecules and polymer brush solution, such a process is defined asself-assembly. With micro nanofluid control technologies and micro mechanicsdeveloping greatly, self-assembly has been an important method to develop newmaterials as well as new function of some existing materials. For example, such aprocess is applied widely in the area of creating reversible, self-repairing material.Also, it offers numerous advantages in biochemically design artificial nanodevices,such as detectors, sensors and the environmental-responsive medicine transfer system.Recent researches on self-assembly mainly focus on the following three areas. First,to reveal the essence of the weak bonds interaction in units and relating collaborativelaws in the self-assembly process. Second, the control of the self-assembly. Third, themanufacture of new self-assembly stuff.To the self-assembly and configurational behaviors of polymer nanofluids innano scale, it is difficult to analyse and observe relating features by usingexperimental methods, especially to the interaction on the interface of theself-assembly system, also to the assemble process under the limit of nano scale. So,in this work, molecular dynamics simulations were conducted for the self-assemblyprocess among amphiphilic block copolymers and polymer brushes, and theconfigurational behaviors,also the control of the polymer nanofluids under nano scale.The researching contents are as follows.(1) We used molecular dynamics simulations to study the assemble process andconfigurational behaviors among the single-wall nanotube and the bottle-like polymerbrush formed by a single chain. Results show that when some conditions are satisfied,the polymer brush can form stable helical conformation. Interaction among thenanotube and the polymer brush played an vital role during the self-assembly processin the composite. Moreover, the grafting density of polymer side chains, with theirlength would affect largely on the equilibrium conformation of the system. (2)We investigated the self-assembly process of diblock copolymers in twoparallel planes. According to varying the concentration,construction of diblockcopolymers and the strength of the interaction between two walls and each block ofcopolymers, we run numerous different simulation to investigate aforementionedfactors' impacts on the composite. Simulation results elucidate that the attraction fromplanes to copolymers and cohesion action inside copolymers are main factors to affectconfigurational behaviors in the self-assembly system.(3)We discussed the self-assembly process in diblock copolymers and thenanotube. In this section, we studied the interaction between copolymers and the innerside of the tube, the outside of the tube, also the inside of the multi-layer tubeseparately.(4)We researched whether the surface conformation and relating propertieswould influence the self-assembly configuration. Results illustrate that we couldutilize the two factors to control and lead the self-assembly system.(5)We use molecular dynamics to investigate the conformational behaviors andcontrol methods of polymer nanofluids. Results show that polymer brushes coating'sresponsive feature to temperature and electricity field strength could be used toachieve the control of nanofluids.Our researching findings will make a contribution to explaining the theory ofself-assembly process more definitely, which is beneficial to conduct theself-assembly process. So, there is great academical and practical value in nanoassembling and nano manufacture...