CAREER: Nanoscale Resolution of Near-Interface Crystallization in Multicomponent Semicrystalline Polymeric Materials

职业：多组分半晶聚合物材料中近界面结晶的纳米级分辨率

• 批准号: 2338613
• 负责人: Kailong Jin
• 金额: $ 64万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-09-01 至 2029-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2338613&HistoricalAwards=false
• 关键词: CAREER; Nanoscale; Resolution; Near; Interface

PART 1: NON-TECHNICAL SUMMARYSemicrystalline polymers comprise ~70% of all synthetic plastics, and they are pervasive in daily life in packaging, transportation, and high-technology applications like microelectronics. Semicrystalline polymers are often used in the form of multicomponent polymeric materials, e.g., multilayer polyethylene/poly(ethylene terephthalate) films for packaging and carbon fiber-reinforced composites for transportation. A key feature of these multicomponent materials is the presence of a large quantity of polymer/polymer or polymer/filler interfaces. Understanding the effects of these interfaces on polymer crystallization is essential to the predictive design of multicomponent materials with desired crystalline structures and properties. Unfortunately, such a fundamental understanding is lacking. This project will work toward closing the fundamental knowledge gap in interfacial effects and polymer crystallization, using a new fluorescence technique with a nanoscale spatial resolution. The fundamental knowledge gained from this research will advance the development of new multicomponent materials with optimized crystalline structures and properties, which can contribute to a broad range of applications such as food packaging and biomedical devices. This project will provide an integrated research and educational experience for graduate students, undergraduate students, and high-school students, including members of underserved groups. The principal investigator and students will also develop education-oriented online videos and hands-on demonstrations to engage the general public and attract K-12 students into STEM fields. PART 2: TECHNICAL SUMMARYThis project’s research goal is to advance fundamental understanding of the interfacial effects on crystallization in multicomponent semicrystalline polymers, using a new fluorescence technique with a nanoscale spatial resolution. The principal investigator (PI) plans to achieve this goal by strategically placing trace amounts of “reporter” (i.e., crystal-sensing) fluorescent dye labels at controlled distances from interfaces to elicit fluorescence-based information about local crystallization and thus interfacial effects. Towards this goal, the PI and students will pursue three research thrusts: (1) Understand the role of fluorescence as a crystallization-sensing mechanism by selectively placing the dyes in rigid vs. mobile amorphous fraction regions to deconvolute their contributions to the overall fluorescence; (2) Study near-interface crystallization by location-specific fluorescence and complementary methods such as grazing-incidence X-ray scattering; (3) Unveil polymer/polymer and polymer/substrate interfacial effects on crystallization and their perturbation length-scale. Material studies will focus on degradable poly(L-lactic acid) (PLLA) as a model semicrystalline polymer to advance the design of new PLLA-based multicomponent materials with desired structures/properties and improved sustainability, including multilayer films, composites, blends, and block copolymers. The education/outreach plan will broaden the reach and benefits of this CAREER research at multiple levels: (1) The PI and students will reach out to the general public through online educational videos on semicrystalline polymers; (2) The PI will develop a new lab module on plastic packaging and leverage the existing research programs at ASU to train graduate students, undergraduate students, and high-school students on polymer synthesis and characterization; (3) The PI and students will develop hands-on demonstrations at ASU Open Door to stimulate local K-12 students’ interest in polymers and STEM careers..This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

第 1 部分：非技术摘要半结晶聚合物约占所有合成塑料的 70%，它们在日常生活中的包装、运输和微电子等高科技应用中普遍存在。例如，用于包装的多层聚乙烯/聚对苯二甲酸乙二醇酯薄膜和用于制造的碳纤维增强复合材料这些多组分材料的一个关键特征是存在大量聚合物/聚合物或聚合物/填料界面，了解这些界面对聚合物结晶的影响对于具有所需晶体结构和性能的多组分材料的预测设计至关重要。不幸的是，缺乏这样的基本理解，该项目将致力于使用具有纳米级空间分辨率的新荧光技术来缩小界面效应和聚合物结晶的基础知识差距，从这项研究中获得的基础知识将推动发展。具有优化晶体结构和性能的新型多组分材料，可促进食品包装和生物医学设备等广泛应用，该项目将为研究生、本科生和高中生提供综合的研究和教育体验。 ，包括服务不足群体的成员。首席研究员和学生还将开发面向公众的在线视频和实践演示，并吸引 K-12 学生进入 STEM 领域。为了加深对多组分半晶聚合物结晶界面效应的基本了解，首席研究员 (PI) 计划通过策略性地放置痕量“报告分子”（即晶体）来实现这一目标。 -传感）荧光染料标记在距界面的受控距离处，以获取有关局部结晶的基于荧光的信息，从而获得界面效应。为了实现这一目标，PI和学生将进行三项研究。推力：（1）通过选择性地将染料放置在刚性和移动的无定形部分区域来了解荧光作为结晶传感机制的作用，以解卷积它们对整体荧光的贡献；（2）通过特定位置研究近界面结晶。荧光和掠入射 X 射线散射等补充方法；(3) 揭示聚合物/聚合物和聚合物/基材界面对结晶及其扰动长度尺度的影响。材料研究将重点关注可降解聚（L-乳酸）（PLLA）作为半结晶聚合物模型，以推进具有所需结构/性能和改进可持续性的新型 PLLA 基多组分材料的设计，包括多层薄膜、复合材料、共混物和教育/推广计划将在多个层面上扩大这项职业研究的范围和效益：(1) PI 和学生将通过在线教育视频向公众宣传。 (2) PI 将开发一个新的塑料包装实验室模块，并利用亚利桑那州立大学现有的研究项目对研究生、本科生和高中生进行聚合物合成和表征方面的培训；学生将在 ASU Open Door 上进行实践演示，以激发当地 K-12 学生对聚合物和 STEM 职业的兴趣。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优势和知识进行评估，被认为值得支持。更广泛的影响审查标准。