Multivalent Assembly of Flexible Polymer Chains into Supramolecular Nanofibers
Multivalent Assembly of Flexible Polymer Chains into Supramolecular Nanofibers
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DOI：
10.1021/jacs.0c07651
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发表时间：
2020-09-30
影响因子：
15
通讯作者：
Bao, Zhenan
中科院分区：
文献类型：
--
作者：
Cooper, Christopher B.;Kang, Jiheong;Bao, Zhenan
自然界中的聚合物材料通常采用有序的分层结构，以执行独特和精确的功能。重要的是，这些结构通常是由许多弱相互作用的协同总和形成和稳定的，而不是由几个强键的独立缔合形成的。在这里，我们表明，合成的，灵活的聚合物链与周期性放置和定向动态键集体组装成超分子纳米纤维时，总分子量低于聚合物的临界缠结分子量。这导致长聚合物链的本体膜具有比相同化学组成的较短聚合物链的膜更快的动力学。纳米纤维的形成使体膜模量增加超过一个数量级，并使终端流动的开始延迟超过100 ° C，同时仍然保持溶液可加工。系统的调查不同的聚合物链结构和动态键合部分沿着与粗粒度的分子动力学模拟照亮了决定聚合物的能力，形成超分子纳米纤维的结构-功能关系。这份报告的合作组装的多价聚合物链到分级，超分子结构有助于我们的基本理解设计仿生功能材料。
Polymeric materials in nature regularly employ ordered, hierarchical structures in order to perform unique and precise functions. Importantly, these structures are often formed and stabilized by the cooperative summation of many weak interactions as opposed to the independent association of a few strong bonds. Here, we show that synthetic, flexible polymer chains with periodically placed and directional dynamic bonds collectively assemble into supramolecular nanofibers when the overall molecular weight is below the polymer's critical entanglement molecular weight. This causes bulk films of long polymer chains to have faster dynamics than films of shorter polymer chains of identical chemical composition. The formation of nanofibers increases the bulk film modulus by over an order of magnitude and delays the onset of terminal flow by more than 100 degrees C, while still remaining solution processable. Systematic investigation of different polymer chain architectures and dynamic bonding moieties along with coarsegrained molecular dynamics simulations illuminate governing structure-function relationships that determine a polymer's capacity to form supramolecular nanofibers. This report of the cooperative assembly of multivalent polymer chains into hierarchical, supramolecular structures contributes to our fundamental understanding of designing biomimetic functional materials.