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.

这项研究旨在通过将新的回收机制引入3D打印材料来提高塑料制造的可持续性。目前，印刷后立即将超过30％的3D打印材料丢弃，这激发了对未来的愿景，即在生产点上回收了3D打印废料。这项研究将推动从“印刷到地填充”的线性经济过渡到“印刷回收者取代”的循环经济。为了实现这一过渡，提出了用于3D打印树脂的点播再生的新型光学回收技术。该项目以研究团队的最新发现为基础，结合了可逆的光化学和基于纳米技术的光化机制，以证明3D打印树脂的光学回收。通过提供低能量，按需选项，可以再生化学活跃的聚合物树脂建立针对光呼应聚合物的设计规则，可以进一步推动大型和高分辨率的构图，用于在半径，光纤维电机和生物材料中应用高分辨率，并将高分辨率构成图案。为了扩大研究的参与，PIS将招募和培训来自代表性不足的人群的研究人员，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（URMS）。研究发现将纳入工程课程，强调基于询问的方法，这些方法将吸引学生参与可持续塑料制造的现实世界挑战。最后，可持续性和成瘾性制造业的概念将通过教育着色书页和“无行话”研究的亮点来解释。教育内容将分发给旧金山湾区的K-8外展活动的更广泛的公众。这项研究的长期目标是通过工程可重复使用的树脂来减少3D打印过程中的塑料废物，这些树脂可以被打印，“被擦除”，并在许多周期上重新印刷。该提案的目的是设计可鲁棒的模块化机制，用于将光学回收利用到聚合物树脂中进行3D打印。工程化树脂包含多臂聚乙烯乙二醇，具有光反应性蒽基团（PEG-蒽）和紫外线发出的上转换纳米胶囊。 peg-蒽中经历了可逆的光偶联反应，以响应紫外光的不同波长。这些反应推动了PEG-蒽网络的聚合和沉积。紫外线发射上转换纳米胶囊被低能可见光激活，比紫外光深入材料。这些纳米胶囊将传递将3D打印材料解放所需的紫外线。本研究计划的目标1将使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沉积反应动力学的影响。假设，由于更快的沉积到较小的组件和较低的溶液粘度上，较短的臂较短的聚合物将更较短。 AIM 2将确定纳米材料稳定性的基础化学原理。封装筛选研究将确定核心稳定纳米胶囊的核心解决方案和表面配体要求。 AIM 3将建立设计规则，以改善光学可回收聚合物树脂的模块化。采用紫罗兰色激活的光电偶联反应将使下一代树脂可轻松整合到现代的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中的补充专业知识。这项研究的更广泛的影响将包括开发新的聚合物处理和回收技术，本科和研究生层面的研究培训和心理，以及有关塑料回收和光学技术的教育和外展内容的部署。该奖项反映了NSF的法定任务，并通过评估基金会的智力和广泛的范围来反映出对支持的法定任务，并已被认为是珍贵的。