In recent years, composite systems of polymers and ionic liquids were paid increasing attentions experimentally. They have been widely used in many important areas, such as proton exchange membrane, self-assembly, catalysis materials, responsive materials and functional adsorbent materials. Computer simulation helps people understand the mesoscopic structures of the composite system, thus providing support and guidance for the development of new materials. This work will explore this complex soft matter system by dissipative particle dynamics.Firstly, mesoscopic structures of Nafion-[Bmim][TfO] ionic liquid(IL) composite membrane were studied. Effects of temperature and IL concentration on the mesoscopic structure were investigated. Microphase-separation phenomena were found. The analysis of pore size distribution in different conditions indicates that, with the increase of IL concentration in composite membrane, the morphology of aggregation is transformed from dispersed IL clusters to coherent IL channels. The chamber structure comes into being when the IL concentration is very high. With temperature elevating, the structure of ionic liquid channels becomes more complex and previous chamber would transform into new branches of channels, indicating IL channels become more coherent at elevated temperatures. The results of interfacial distribution probabilities and radial distribution functions indicate that, alkyl chain of ionic liquids would be embedded in the backbone of Nafion, and the change of distribution of sulfonnic acid groups in side chains directly affects the distribution of imidazole groups and anions at the microphase interface.Secondly, the self-assembled phase behaviors of amphiphilic block polymer PB-b-PEO and ionic liquid [Bmim][PF6] system were explored systematically.The effect of ratios of PB, PEO, [Bmim][PF6] on phase morphologies; the pattern of transformation is analyzed and ternary phase diagram was depicted. Simulation results show that at low polymer concentrations, PB-b-PEO behaves as dispersed phase, under different block ratio, the phase morphologies can vary as spherical, rod-like micelles, vesicles, sheets, etc. As the concentration increases, PB-b-PEO behaves as continuous phase in system, under different block ratio, the phase morphologies can show as worm-like micelles, branched lamellae, tube and platelet, and [Bmim][PF6] also gradually transforms from dispersed phase to continuous phase, the IL micro-phase structure is formed.Finally, mesoscopic structures of Nafion-[Bmim][BF4] composite membrane were simulated, and compared with the structure of [Bmim][TfO] system. It is found that the similar micro-phase separation exists, but mesoscopic structures of [Bmim][BF4] system show better overall channel-like IL distribution and the distribution of anions has an important effect on the micro-phase interface. To obtain the single-direction channel for better performance of proton transfer, PVdF-co-HFP is added to construct blend membrane. According to results, the copolymerization ratio of Nafion would affect the IL channel structure and the distribution of Nafion; blend ratio of polymer would affect coherent states of IL in the membrane, from uncontinuous to unidirectional and to multidirectional structures; IL concentration would directly affect the formation of continuous phase of IL. When copolymerization ratio is 11: 1, blend ratio is 10: 90, and IL concentration is 0.3, the single-direction channel structure can be obtained. |