Morphological Transition of π-shaped Graft Copolymer in Equilibrium and Non-equilibrium System via Dissipative Particle Dynamics Simulation

• Main Author: 吳育銘
• Other Authors: 張榮語
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/yen3j8

碩士 === 國立清華大學 === 化學工程學系 === 101 === In this thesis, we use dissipative particle dynamics simulation to discuss the morphological transition of π-shaped graft copolymer under equilibrium and non-equilibrium system, by changing the number of particles grafted and the molecular concentration. The π-shaped graft copolymer is composed of hydrophilic polymer, hydrophobic polymer, and strong hydrophobic polymer. Under the equilibrium system, it becomes spherical or cylindrical structure in low concentration, and network or lamellas in high concentration in this study. When the concentration is up to 100 percent, the porous structure, which is wide applicable, is observed in this study. Under the non-equilibrium system, we find that the final morphology and its direction are affected under the flow-field. Interestingly, the molecular 622 becomes a special striped morphology, and we believe this structure is useful in nanotechnology. At the end of the thesis, we make all the morphology into a phase diagram. It is easy for the experimental operator to get the desired morphology by changing the number of particles grafted or the molecular concentration. Later on, we discuss the relationship between the viscosity and concentration. The trend is that when the concentration increases, the viscosity increases, too. However, some viscosity is unexpected, due to the effect of the morphology or intermolecular forces. In the future, we hope these results can solve the problem in optoelectronics, biotechnology, medicine, or nanotechnology.