Diblock copolymers are valued for their ability to form thin films with nanoscale features that typically reflect those of their microphase-separated structures in concentrated solution. Here, we show that such self-assembled structures can be easily formed with diblock copolymers composed of thermally responsive polypeptides, such as resilin-like polypeptides (RLP) and elastin-like polypeptides (ELP), by exploiting the inverse temperature transition behavior of ELPs in aqueous media. Specifically, we examine the self-assembly of a series of RLP-b-ELP diblock copolypeptides in concentrated aqueous solution (30 and 50 wt %) by small-angle X-ray scattering (SAXS). By systematically varying RLP block length and temperature (10–45 °C), we observed microphase separation into hexagonally packed cylinders and lamellae. By analyzing the observed order–order transitions (OOT) and order–disorder transitions (ODT), we determined that self-assembly in this system is primarily driven by polymer–solvent interactions. While these thermally responsive polymers showed clear ODTs and OOTs at certain temperatures, temperature only had a weak effect on the spacing of the resulting nanostructures. In contrast, we found that nanostructure spacing was far more sensitive to RLP block length. Finally, we used atomic force microscopy (AFM) to demonstrate that spin casting RLP-b-ELP diblock copolypeptides also produce nanostructured thin films with spacings that correlate with those in concentrated solution.

中文翻译：

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浓缩溶液中树脂样和弹性蛋白样二嵌段共聚肽的微相分离

二嵌段共聚物因其形成具有纳米级特征的薄膜的能力而受到重视，这些纳米级特征通常反映了它们在浓缩溶液中的微相分离结构。在这里，我们表明，通过利用 ELP 的逆温度转变行为，这种自组装结构可以很容易地由热响应多肽组成的二嵌段共聚物形成，例如弹性蛋白样多肽 (RLP) 和弹性蛋白样多肽 (ELP)在水性介质中。具体来说，我们检查了一系列 RLP- b的自组装-通过小角 X 射线散射 (SAXS) 在浓缩水溶液（30 和 50 wt%）中的 ELP 二嵌段共聚肽。通过系统地改变 RLP 块长度和温度 (10–45 °C)，我们观察到微相分离成六角形堆积的圆柱体和薄片。通过分析观察到的有序-有序转变 (OOT) 和有序-无序转变 (ODT)，我们确定该系统中的自组装主要是由聚合物-溶剂相互作用驱动的。虽然这些热响应聚合物在特定温度下显示出清晰的 ODT 和 OOT，但温度对所得纳米结构的间距影响很小。相比之下，我们发现纳米结构间距对 RLP 块长度更为敏感。最后，我们使用原子力显微镜 (AFM) 证明旋转铸造 RLP- b-ELP 二嵌段共聚肽还产生纳米结构薄膜，其间距与浓缩溶液中的间距相关。