Engineering optically recyclable polymer resins for sustainable additive manufacturing

工程光学可回收聚合物树脂用于可持续增材制造

• 批准号: 2400010
• 负责人: Danielle Mai
• 金额: $ 39.13万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-04-01 至 2027-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2400010&HistoricalAwards=false
• 关键词: Engineering; optically; recyclable; polymer; resins

This research seeks to improve the sustainability of plastics manufacturing by introducing new recycling mechanisms into 3D-printing materials. Currently, over 30% of 3D-printed materials are discarded immediately after printing, motivating a vision of the future where 3D-printing scraps are recycled at the point of production. This research will drive a transition from a linear economy of “print-to-landfill” to a circular economy of “print–recycle–reprint.” To achieve this transition, novel optical recycling technologies for on-demand regeneration of 3D-printing resins are proposed. Building on recent discoveries by the research team, this project combines reversible photochemistry and nanotechnology based light delivery mechanisms to demonstrate the optical recycling of 3D-printing resins. Optically recyclable resins have potential to transform plastics processing beyond 3D printing by providing low-energy, on-demand options to regenerate chemically active polymer resins that can be reused over numerous cycles. Establishing design rules for photoresponsive polymers will further advance large-format and high-resolution patterning for applications in semiconductors, optoelectronics, and biological scaffold materials. To broaden participation in research, the PIs will recruit and train researchers from underrepresented populations including women, first-generation and low-income (FLI) students, and underrepresented minorities (URMs). Research findings will be integrated into engineering coursework, emphasizing inquiry-based approaches that will engage students in the real-world challenge of sustainable plastics manufacturing. Finally, concepts in sustainability and additive manufacturing will be explained through educational coloring book pages and “no jargon” research highlights. Educational content will be distributed to the broader public online and at K-8 outreach events across the San Francisco Bay Area. The long-term goal of this research is to reduce plastic waste from 3D printing processes by engineering reusable resins that can be printed, “erased,” and re-printed over numerous cycles. The objective of this proposal is to engineer robust, modular mechanisms for optical recycling into polymer resins for 3D printing. Engineered resins comprise multi-arm polyethylene glycol with photoresponsive anthracene end groups (PEG-anthracene) and UV-emitting upconversion nanocapsules. PEG-anthracene undergoes reversible photocoupling reactions in response to different wavelengths of UV light; these reactions drive polymerization and depolymerization of PEG-anthracene networks. UV-emitting upconversion nanocapsules are activated by low-energy visible light that penetrates deeper into materials than UV light; these nanocapsules will deliver UV light needed to depolymerize 3D-printed materials. Aim 1 of this research plan will quantify the influence of polymer structure on photo-polymerization and depolymerization reaction kinetics using in situ dynamic rheology measurements and a reaction-diffusion model. It is hypothesized that polymers with fewer, shorter arms will be more amenable to optical recycling due to faster depolymerization into smaller components and lower solution viscosities. Aim 2 will identify the chemical principles underlying the stability of upconversion nanomaterials. Encapsulation screening studies will determine the core solvent and surface ligand requirements for robust stabilization of UV-emitting nanocapsules. Aim 3 will establish design rules to improve the modularity of optically recyclable polymer resins. The adoption of violet-activated photocoupling reactions will enable facile integration of next-generation resins into modern 3D printers. This work will leverage complementary expertise of the PIs in polymer engineering, rheology, optical nanomaterials, and additive manufacturing. Broader impacts from this research will include the development of new polymer processing and recycling technologies, research training and mentorship at the undergraduate and graduate levels, and deployment of educational and outreach content about plastic recycling and optical technologies.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.

这项研究旨在通过在3D打印材料中引入新的回收机制来提高塑料制造的可持续性。目前，超过30%的3D打印材料在打印后立即被丢弃，这激发了一种未来的愿景，即3D打印废料在生产时被回收。这项研究将推动从“打印到垃圾填埋”的线性经济向“打印-回收-再打印”的循环经济转变。为了实现这一转变，提出了按需再生3D打印树脂的新型光学回收技术。在研究团队最新发现的基础上，该项目结合了可逆光化学和基于纳米技术的光传输机制，以演示3D打印树脂的光学回收。光学可回收树脂通过提供低能耗、按需选项来再生化学活性聚合物树脂，从而有可能将塑料加工转变为3D打印以外的方式，这些聚合物树脂可以在多次循环中重复使用。建立光响应性聚合物的设计规则将进一步推动大幅面和高分辨率图案化在半导体、光电子和生物支架材料中的应用。为了扩大对研究的参与，私人投资机构将从代表性不足的人群中招聘和培训研究人员，包括妇女、第一代和低收入(FLI)学生以及代表性不足的少数民族(URM)。研究成果将被整合到工程课程中，强调以探究为基础的方法，使学生参与可持续塑料制造的现实世界挑战。最后，可持续发展和添加剂制造的概念将通过教育配色书籍页面和“无术语”研究亮点来解释。教育内容将在网上和旧金山湾区的K-8外展活动中分发给更广泛的公众。这项研究的长期目标是通过设计可重复使用的树脂来减少3D打印过程中的塑料垃圾，这些可重复使用的树脂可以打印、擦除和重复打印多次。这项提议的目标是设计出坚固的模块化机制，用于3D打印的聚合物树脂中的光学回收。工程树脂由多臂聚乙二醇光响应性蒽端基(聚乙二醇菲)和紫外光发射上转换纳米胶囊组成。在不同波长的紫外光作用下，聚乙二醇菲发生可逆光偶联反应，这些反应驱动聚乙二醇菲网络的聚合和解聚。发射紫外光的上转换纳米胶囊被比紫外光更深入材料的低能量可见光激活；这些纳米胶囊将提供解聚3D打印材料所需的紫外光。本研究计划的目标1将利用原位动态流变学测量和反应扩散模型来量化聚合物结构对光聚合和解聚反应动力学的影响。据推测，臂更少、更短的聚合物由于更快地解聚成更小的组分和更低的溶液粘度，将更容易进行光学回收。目标2将确定上转换纳米材料稳定性的潜在化学原理。胶囊筛选研究将确定紫外线发射纳米胶囊稳健稳定所需的核心溶剂和表面配体。目标3将建立设计规则，以提高光学可回收聚合物树脂的模块化。采用紫光激活的光偶联反应将使下一代树脂能够轻松地集成到现代3D打印机中。这项工作将利用PI在聚合物工程、流变学、光学纳米材料和添加剂制造方面的互补专业知识。这项研究的更广泛影响将包括开发新的聚合物加工和回收技术，本科生和研究生水平的研究培训和指导，以及部署关于塑料回收和光学技术的教育和推广内容。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更广泛的影响审查标准进行评估，被认为值得支持。