Polymer Crystallization at Curved Liquid/Liquid Interface

技术综述：曲线空间与具有三维(3D)平移对称的典型有序结构不相称。然而，软物质在组装时，包括胶体、两亲性和嵌段共聚物(BCP)，通常形成描绘曲面/界面的结构。例如脂质体、胶体、球形胶束、蠕虫状胶束和囊泡(也称为聚合体)。对于结晶的BCP，结晶往往会覆盖弯曲的几何形状，因为后者与结晶顺序不相称。另一方面，在结晶聚合物中经常观察到扭曲和弯曲的晶体。对于这些非平坦的晶体形态，人们提出了不同的机制。一个耐人寻味的问题是：弯曲空间和结晶有序如何在聚合物体系中共存？在这项工作中，PI建议使用乳液-溶液结晶方法系统地研究L/L弯曲界面上的聚合物溶液结晶。该项目的目标是：1)了解L/L弯曲界面上的聚合物单晶生长机理；2)了解弯曲聚合物单晶的结构和力学性能；3)利用聚合物单晶制备多组分贝壳系综。从科学的角度来看，在弯曲的无公度空间中填充水晶链是一个有趣的研究问题。从技术的角度来看，如果成功，这种控制良好的单组分或多组分的系综不仅将有助于将聚合物胶囊用于药物输送和基因治疗，而且在催化、表面增强拉曼光谱和人造纳米管等应用中也将非常有用。非技术摘要：在结晶大分子中经常观察到扭曲和弯曲的晶体，如聚合物。这很耐人寻味，因为根据定义，晶体应该形成平面，而不是曲面。在这项工作中，PI建议研究弯曲空间中的聚合物结晶，更重要的是，引导聚合物形成半径约为人类头发直径千分之一的微小晶壳！这些微小的贝壳可以被用作胶囊，将药物运送到治疗疾病所需的特定位置。从技术角度来看，这项拟议的研究如果成功，将为提高聚合物胶囊的药物输送性能铺平道路，因为这些胶囊比目前使用的许多其他系统更稳定。该提案的教育部分包括：1)通过开发将在纳米结构聚合物材料课程中使用的两个课程单元，解决聚合物纳米科学和纳米技术的现代发展的教育需要。2)让研究生、本科生、高中生和教师，特别是代表性不足的人群，参与拟议的研究活动。

TECHNICAL SUMMARY: Curved space is incommensurate with typical ordered structures with three-dimensional (3D) translational symmetry. However, upon assembly, soft matter, including colloids, amphiphiles, and block copolymers (BCPs), often forms structures depicting curved surface/interface. Examples include liposomes, colloidosomes, spherical micelles, worm-like micelles, and vesicles (also known as polymersomes). For crystalline BCPs, crystallization oftentimes overwrites curved geometries since the latter is incommensurate with crystalline order. On the other hand, twisted and curved crystals are often observed in crystalline polymers. Various mechanisms have been proposed for these non-flat crystalline morphologies. One intriguing question would be: how do curved space and crystalline order co-exist in polymeric systems? In this work, the PI proposes to systematically investigate polymer solution crystallization at curved L/L interface using an emulsion-solution crystallization method. The objectives of the project are: 1) understanding the polymer single crystal growth mechanism at curved L/L interface; 2) understanding structure and mechanical properties of curved polymer single crystals; and 3) fabricating multicomponent shell ensembles using polymer single crystals. From a scientific standpoint, packing crystalline chains in a curved incommensurate space is an intriguing question to study. From a technological standpoint, if successful, the well-controlled single- or multiple-component ensembles will not only shed light on using polymeric capsules for drug delivery and gene therapeutics, they can also be extremely useful for applications such as catalysis, surface enhanced Raman spectroscopy, and artificial nanomotors.NON-TECHNICAL SUMMARY: Twisted and curved crystals are often observed in crystalline large molecules such as polymers. This is intriguing because by definition, crystals should lead to flat instead of curved surfaces. In this work, the PI proposes to investigate polymer crystallization at curved space and more importantly, to guide polymers to form tiny crystal shells whose radii are about one thousandth the diameter of a human hair! The tiny shells can be used as capsules to deliver drugs to specific locations needed to cure diseases. From a technological standpoint, the proposed research, if successful, will pave the way to improving the performance of polymeric capsules for drug delivery because these capsules are more stable than many other systems that are currently used. The educational component of the proposal includes: 1) addressing the need for the education of modern developments in polymer nanoscience and nanotechnology by developing two class modules which will be used in the Nanostructured Polymeric Materials course. 2) Involving graduate, undergraduate, high school students and teachers, particularly under-represented populations, in the proposed research activities.