Shin Minjoong, Kim Hayeon, Park Geonhyeong, Park Jongmin, Ahn Hyungju, Yoon Dong Ki, Lee Eunji, Seo Myungeun
Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.
School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Republic of Korea.
Nat Commun. 2022 May 4;13(1):2433. doi: 10.1038/s41467-022-30122-z.
Randomness is perceived in two different extremes, in macroscopic homogeneity and local heterogeneity, but apparently far away from order. Here we show that a periodic order spontaneously arises from a binary random copolymer when self-assembly occurs in an ensemble containing > 10 possible chain sequences. A Bernoullian distribution of hydrophilic and hydrophobic side chains grafted onto a linear backbone was constructed by random copolymerization. When the polymer chains associate in water, a sequence matching problem occurs because of the drastic heterogeneity in sequence: this is believed to generate local curvature mismatches which deviate from the ensemble-averaged interfacial curvature. Periodic folding of the self-assembled bilayer stabilizes the curvature instability as recurring hinges. Reminiscent of chain-folded lamellae found in polymer crystallization, this new liquid crystalline mesophase, characterized as bilayer-folded lamellae, manifests itself as an anisotropically alignable birefringent hydrogel with structural hierarchy across multiple length scales.
随机性在两种不同的极端情况中被感知到，即在宏观均匀性和局部异质性中，但显然远离有序状态。在这里，我们表明，当自组装发生在包含超过10种可能链序列的集合中时，二元无规共聚物会自发地产生周期性有序结构。通过无规共聚构建了接枝到线性主链上的亲水性和疏水性侧链的伯努利分布。当聚合物链在水中缔合时，由于序列中的剧烈异质性会出现序列匹配问题：据信这会产生偏离整体平均界面曲率的局部曲率失配。自组装双层的周期性折叠作为反复出现的铰链稳定了曲率不稳定性。这种新的液晶中间相让人联想到在聚合物结晶中发现的链折叠片晶，其特征为双层折叠片晶，表现为一种具有跨多个长度尺度结构层次的各向异性可取向双折射水凝胶。
