Construction of Rod-Forming Single Network Mesophases in Rod-Coil Diblock Copolymers via Inversely Designed Phase Transition Pathways
Construction of Rod-Forming Single Network Mesophases in Rod-Coil Diblock Copolymers via Inversely Designed Phase Transition Pathways
复制标题
通过逆向设计相变途径构建棒-螺旋二嵌段共聚物中的棒形成单网络中间相
DOI：
10.1021/acs.macromol.8b00773
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发表时间：
2018
期刊：
影响因子：
5.5
通讯作者：
Yang Yuliang
中科院分区：
文献类型：
--
作者：
Sun Tongjie;Liu Faqiang;Tang Ping;Qiu Feng;Yang Yuliang
将弦方法引入到自洽平均场理论中，研究了棒状-卷曲嵌段共聚物的相变动力学。在我们改进的弦方法中使用的等弧长参数化约束的密度和取向顺序参数，以获得准确和稳定的最小能量路径（MEP）。针对不同的单网络形成的杆作为目标结构，我们开发了一种逆设计的动力学途径的策略。通过设计不同的初始结构（薄片或圆柱）与特定的对称性匹配的目标结构作为字符串的两端，我们计算MEP和分析链刚性对相变动力学的影响。结果表明，属于同一晶面群的层状结构之间的重排转变可以诱导亚稳单网络的形成。刚性棒的形状和排列方式会影响外延相变。目标结构的长期稳定性可以通过调整嵌段组成以及刚性和柔性段之间的几何不对称性来调节，这可以指导实验来制造长寿命的单网络。
The string method is introduced to the self-consistent mean-field theory for rod–coil diblock copolymers to investigate the phase transition kinetics. The equal arc length parametrization used in our improved string method is constrained on both the density and orientation order parameters to obtain accurate and stable minimum energy pathways (MEP). Focusing on different single networks formed by rods as the target structures, we developed an inverse design strategy of kinetic pathways. By designing distinct initial structures (lamellae or cylinders) with specific symmetry matching the target structure as the two ends of the string, we calculated the MEP and analyzed the effects of chain rigidity on the phase transition kinetics. The results indicate that the reordering transition between lamellae belonging to the same crystallographic plane group can induce the formation of metastable single networks. The shape and arrangement of the rigid rods will influence the epitaxial phase transition. The long-term stability of the target structures can be regulated by tailoring the block composition as well as the geometrical asymmetry between rigid and flexible segments, which may guide the experiments to fabricate long-lived single networks.