Collaborative Research: Fundamental studies of porous polymers for selective gold retrieval

密苏里大学堪萨斯城分校（UMKC）和南卫理公会大学（SMU）的研究人员将研究如何利用多孔聚合物从废物流中回收金离子。从电子废物中回收黄金具有显著的环境和经济效益。2022年，全球电子垃圾回收市场规模约为553亿美元，其中黄金回收占最大价值。吸附技术被认为是一种高效、简单、经济、环保的分离方法。但目前基于吸附法的金回收技术存在吸附量小、吸附速率慢、选择性低等问题。该项目将开发吸附剂，用于有效和高效地回收可充电电池应用所需的黄金和其他金属离子，促进美国在能源和国防领域的全球领导地位。该项目支持研究生和本科生的跨学科培养。研究人员与UMKC的多元文化学生事务办公室和SMU的参与学习、麦克奈尔学者和汉密尔顿本科生研究学者项目合作，从STEM中代表性不足和服务不足的群体中招募学生。研究结果将在同行评议的期刊、会议和在线媒体上广泛传播。系统的实验和理论研究将深入了解基于本征多孔三嗪交联聚乙烯亚胺（TCPEI）网络的新型吸附剂与金离子之间的相互作用。主要完成四项研究任务：(1)设计并合成三种不同类型胺态氮分布显著不同的TCPEIs系列；(2)实验和理论研究了三套TCPEIs对金离子的吸附能力和吸附能；(3)通过实验和理论确定吸附和解吸动力学；(4)探索TCPEIs对电子垃圾中常见的其他金属离子（如铅、汞、镍、钴、锰、镉、铬、铁和铜）的金吸附选择性。该研究有望引领以吸附为基础的先进金回收技术。通过本研究获得的基础知识也可以应用于开发其他金属离子的吸附剂，包括关键金属。研究生和本科生研究人员将接受培训，合成这些独特的聚合物，测量和表征聚合物的金属离子吸附性能，并进行理论研究，以了解吸附过程和聚合物性能。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Investigators at the University of Missouri – Kansas City (UMKC) and Southern Methodist University (SMU) will investigate how to retrieve gold ions from waste streams using porous polymers. Recovering gold from electronic waste (e-waste) has significant environmental and financial benefits. The global e-waste recycling market reached around $55.3 billion in 2022, with gold recovery accounting for the most value. Adsorption technology is regarded as a highly effective, simple, economical, and environmentally benign separation method. However, current adsorption-based gold recovery technology suffers from low adsorption capacity, slow adsorption rates, and low selectivity. This project will develop adsorbents for the effective and efficient recovery of gold and other metal ions essential for rechargeable battery applications, promoting the United States’ global leadership in the energy and defense sectors. This project supports the interdisciplinary training of graduate and undergraduate students. The investigators have partnered with UMKC’s Multicultural Student Affairs Office and SMU’s Engaged Learning, McNair Scholars, and Hamilton Undergraduate Research Scholars programs to recruit students from underrepresented and underserved groups in STEM. The research results will be broadly disseminated in peer-reviewed journals, conferences, and online outlets. Systematic experimental and theoretical studies will be conducted to gain fundamental insights into the interactions between gold ions and novel adsorbents based on intrinsically porous triazine-crosslinked polyethyleneimine (TCPEI) networks. Four research tasks will be completed: (1) design and synthesize three series of TCPEIs with dramatically different distributions of the various types of amine nitrogen; (2) experimentally and theoretically study the gold ion adsorption capacities and energies of the three sets of TCPEIs; (3) experimentally and theoretically determine adsorption and desorption kinetics; and (4) explore the gold adsorption selectivity of TCPEIs over other metal ions commonly found in e-waste such as lead, mercury, nickel, cobalt, manganese, cadmium, chromium, iron, and copper. The research is expected to lead to advanced adsorption-based gold recovery technology. The fundamental knowledge gained through this study may also be applied to develop adsorbents for other metal ions, including critical metals. The graduate and undergraduate student researchers will be trained to synthesize these unique polymers, measure and characterize the polymers’ metal ion adsorption properties, and perform theoretical studies to understand adsorption processes and polymer properties.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.