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：非技术摘要半晶体聚合物占所有合成塑料的70％，并且它们在包装，运输和高科技应用（如微电子）的日常生活中普遍存在。半晶体聚合物通常以多组分聚合物材料的形式使用，例如多层聚乙烯/聚苯二甲酸乙二醇酯）膜，用于包装和碳纤维增强的组合物进行运输。这些多组分材料的关键特征是存在大量的聚合物/聚合物或聚合物/填充界面。了解这些界面对聚合物结晶的影响对于具有所需结构结构和特性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本知识差距。从这项研究中获得的基本知识将推进具有优化的晶体结构和特性的新的多组分材料的开发，这可以有助于广泛的应用，例如食品包装和生物医学设备。该项目将为研究生，本科生和高中生（包括服务欠佳的小组成员）提供综合的研究和教育经验。首席调查员和学生还将开发面向教育的在线视频和动手演示，以吸引公众和吸引力K-12学生进入STEM领域。第2部分：技术摘要这项项目的研究目标是使用具有纳米级空间分辨率的新荧光技术，对多组分半结晶聚合物的结晶效果进行基本了解。首席研究员（PI）计划通过策略性地放置痕量的“记者”（即晶体感应）荧光染料标签，以从界面受控距离以触发有关局部结晶的荧光信息，从而实现了界面，从而实现了这一目标。为了实现这一目标，PI和学生将追求三个研究的推力：（1）通过选择性地将染料与刚性与移动无定形分数区域选择性地置于荧光内，以将其对整体荧光的贡献进行反应； （2）研究通过特定于位置的荧光和互补方法（例如放牧X射线散射）的近乎接口结晶； （3）揭开聚合物/聚合物/聚合物/底物干扰对结晶及其扰动长度尺度的影响。材料研究将侧重于可降解的聚（L-乳酸）（PLLA）作为模型的半结晶聚合物，以推动具有所需结构/特性和改善可持续性的新的基于PLLA的多组分材料的设计，包括多层膜，组合，混合物，混合物和块共聚物。教育/外展计划将在多个层面上扩大这项职业研究的影响力和好处：（1）PI和学生将通过半结晶聚合物的在线教育视频与公众联系； （2）PI将开发一个有关塑料包装的新实验室模块，并利用ASU的现有研究计划来培训研究生，本科生以及高中生的聚合物合成和表征； （3）PI和学生将在ASU开放大门开发动手演示，以刺激当地的K-12学生对聚合物和STEM职业的兴趣。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点评估来支持的，并具有更广泛的影响。