Materials with dynamic surface topography may enable a variety of new technologies from smart coatings to biomaterials with controlled cell–material interaction. However, current approaches to create morphing surfaces require programming procedures, either before or after polymerization, that complicate the application of these materials. Here, we exploit the metastability of the microstructure of semicrystalline polymer networks that crystallize while photopolymerizing to create polymer coatings and microstructures that irreversibly morph from smooth to rough in an emergent manner when heated. For example, a smooth polymer coating with a root-mean-square (R_q) roughness of 15 nm transforms into a rough film with a R_q roughness of 688 nm on heating through the melt temperature. We show that this behavior is observed across a range of polymer networks and that the degree of undercooling during polymerization is the primary factor that controls the magnitude of roughness. This technique is not limited to polymer films; microstructures fabricated utilizing micromolding or emulsion polymerization also undergo changes in roughness on heating. Finally, we discuss using this approach to create polymer structures with spatiotemporal control of coefficients of friction and contact angles.

中文翻译：

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通过同时结晶和聚合实现的新兴表面形貌

具有动态表面形貌的材料可能支持从智能涂料到具有受控的细胞-材料相互作用的生物材料在内的多种新技术。然而，当前产生变形表面的方法需要在聚合之前或之后的编程程序，这使这些材料的应用复杂化。在这里，我们利用半结晶聚合物网络的微观结构的亚稳定性，这些晶体在光聚合时会结晶，从而形成聚合物涂层和微观结构，这些涂层在受热时会以不可逆的方式从光滑状态变为粗糙状态。例如，具有15 nm均方根（R _q）粗糙度的光滑聚合物涂层会转变成具有R _q的粗糙膜加热至熔体温度时粗糙度为688 nm。我们表明，这种行为在一系列聚合物网络中都可以观察到，并且聚合过程中的过冷程度是控制粗糙度大小的主要因素。该技术不限于聚合物膜；它还可以是聚合物膜。利用微成型或乳液聚合制造的微结构在加热时也会发生粗糙度变化。最后，我们讨论使用这种方法创建具有时空控制摩擦系数和接触角的聚合物结构。