Patterning polymeric materials with controllable microstructures can meet diversified requirements and realize promising applications. Exploring micro-/nano-pattern methodology offers possibilities for future techniques, however, the self-organized growth of polymeric materials has some limitations and the development of direct and noncontact patterning processes is still challenging. In this work, the study presents a facile strategy for endowing polymers with spatially regulated microstructures by direct photo-printing, which incorporates both advantages of typical top-down and bottom-up approaches. By employing the photodimerization of anthracene-containing semi-crystallized polymers, the gradient crosslinking results in a mismatch of thermal expansion coefficients between the crosslinked surface and the uncrosslinked bottom layer. After heating treatment, constrained by the crosslinked surface, the uncrosslinked bottom polymer of the molten state in the exposed region tends to flow and migrate toward the unexposed region, similar to a volcanic eruption, which accurately determines the height and morphology of pattern. Besides, the well-defined patterns can controllably grow upon thermal treatment due to phase transformation and migration. The versatility of the proposed strategy not only provides a brand-new reliable platform to pattern functional materials with photo-regulated and reversible microstructures, but also promotes the development of smart materials that can find applications in information safety, reversible microfluidics, and electronic devices.

中文翻译：

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光敏半结晶聚合物上表面微图案的光定向生长


具有可控微观结构的图案化聚合物材料可以满足多样化的需求，并实现有前景的应用。探索微/纳米图案方法为未来的技术提供了可能性，但是，聚合物材料的自组织生长有一些局限性，直接和非接触式图案化工艺的开发仍然具有挑战性。在这项工作中，该研究提出了一种通过直接照相打印赋予聚合物空间调控微观结构的简单策略，该策略结合了典型的自上而下和自下而上方法的优点。通过采用含蒽半结晶聚合物的光二聚化，梯度交联导致交联表面和未交联底层之间的热膨胀系数不匹配。热处理后，受交联表面的约束，暴露区熔融状态的未交联底聚合物倾向于流向未暴露区域，类似于火山喷发，准确决定了图案的高度和形态。此外，由于相变和迁移，定义明确的图案可以在热处理后可控地生长。所提出的策略的多功能性不仅提供了一个全新的可靠平台来为具有光调节和可逆微结构的功能材料建模，而且还促进了智能材料的发展，这些材料可以在信息安全、可逆微流体和电子设备中找到应用。