| Summary: | 碩士 === 國立臺灣大學 === 化學工程學研究所 === 106 === Smart membrane is a novel material which can spontaneously change its properties and selectively form funnel-like pores in response to environmental changes. The material has significant potential for applications in biomedical engineering. In this study, dissipative particle dynamics (DPD) was used to study the membrane properties formed by amphiphilic ABA triblock copolymers. We investigate the effects of chain stiffness, compatibility of A block and B block, and chain length on the behavior of the self-assembled membrane.
It is found that the ABA polymers with distinct stiffness can exhibit various equilibrium conformations. Within a certain interval of stiffness, funnel-shaped channels will form and the membrane contains many perforated pores. By observing the configuration of the polymers near the pore, it is found that the stiffness affects the structure and arrangement of the polymer chain and thus is the essential factor influencing the formation of a pore. If it is difficult for the polymers to arrange themselves in an ordered formation, perforated holes will form during the self-assembly process.
We have also investigated the effects of chain length and interaction parameter on the pore-forming ability of the ABA membrane. As the incompatibility of A blocks and B blocks increases, the pore size increases. On the other hand, as the A and B blocks become more solvophobic, the pore size declines accordingly. The block lengths of A and B are found to enhance and deteriorate the magnitude of the pore size, respectively. We have also found that the pore size can be regulated by mixing triblock copolymers of different pore-forming ability. The mixing ratio has great impact on the pore size distribution.
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