介观动力学模拟嵌段聚合物:形貌与动力学

用介观动力学方法对聚氧丙烯-聚氧乙烯(PPO-PEO)类嵌段聚合物溶液进行了模拟研究,由该方法可直接得到聚合物水溶液体系的三维不规则介观形貌与动力学演变过程。该文讨论了聚合物溶液浓度及嵌段聚合物组成等因素对溶液介观形貌和体系性质的影响,讨论了聚合物溶液体系的动力学演变过程以及相互作用参数和聚合物组成对其影响。研究结果表明,随着溶液浓度、疏水组分的减少,体系的介观形貌逐渐从凝胶向胶束状态过渡;聚合物水溶液介观形貌的形成可分为两个阶段:溶液体系很快形成凝胶或胶束形貌并在此后相对较长的时段内形貌发生微变,使体系能量不断降低,趋向平衡状态;聚合物PPO组分的增多或相互作用参数的增加,疏水核越容易形成,介观相分离越快。

Mesoscopic dynamics simulation of diblock copolymer:Morphology and kinetics

Mesoscopic dynamics was used to simulate 3-D irregular mesoscale morphologies and kinetics of aqueous solutions of diblock copolymer PPO(ethylene oxide)-PEO(propylene oxide).The influence of the relative content of PPO and the concentration of the copolymer on the morphology and the mixture properties were discussed.The evolution of the kinetics and the influence of the relative PPO and interaction parameters on the evolution are also discussed.The results show that the morphology of the mixture evolves from gel to micelle as the polymer concentration or PPO content decrease.The formation of the mesoscale morphologies in an aqueous polymer solution can be divided into a rapid gel or micelle formation followed by imperceptible changes of the mesoscale morphologies,with decreasing system energy and the system tending to equilibrium.Furthermore,the PPO content in the aqueous poplymer solution and the interaction parameters affect the evolution process.Increased PPO content or interaction parameters facilitate formation of the hydrophobic core and separation of the two phases.