Upcycling Plastic Waste into Graphitic Carbon - Identifying the Roles of Oxygen Content and sp2 Extent in Graphene Forms: Complementary Tests with LDPE and PET

将塑料废物升级改造为石墨碳 - 确定石墨烯形式中氧含量和 sp2 程度的作用：LDPE 和 PET 的补充测试

• 批准号: 2309333
• 负责人: Randy Vander Wal
• 金额: $ 38.44万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2309333&HistoricalAwards=false
• 关键词: Upcycling; Plastic; Waste; into; Graphitic

The proposed study seeks to upcycle consumer plastic waste into high value graphitic carbons for electric vehicles and renewable energy storage. Presently, petroleum and coal are the precursors for graphitic carbons used in Li-ion batteries. These sources are non-renewable and require substantial energy input for their processing. This research program will test the hypothesis that plastic waste constitutes a high-quality feedstock for graphene given its higher purity and uniformity compared to natural graphite. Upcycling waste plastic into high-value graphitic carbons will lead to improved recycling economics, increased recycling infrastructure investment, and growth of the recycling workforce while reducing greenhouse gas emissions and raising public awareness for recycling. This upcycling approach recovers the embodied energy cost of the plastic materials while trapping the carbon as a solid. As a new “resource,” plastic waste would eliminate petroleum and coal as feedstocks and displace mining for natural graphite. Upcycling plastic waste could transform the plastics recycling economy and thereby reduce plastic pollution, contributing to sustainability and adding a new path to a circular carbon economy. Outreach efforts include a) increasing diversity by summer internships for women in science and engineering research, b) promoting K-12 STEM through one-week science camps; and c) after-school events along with d) public dissemination via YouTube videos. The proposed study seeks to upcycle consumer plastic waste into high value graphitic carbons for electric vehicles and renewable energy storage. Low- and high-density polyethylene (LDPE, HDPE) and polyethylene terephthalate (PET) bracket the challenges of forming graphitic carbons from varied waste plastic feedstocks: high aliphatic (hydrogen) content (LDPE) and high oxygen content (PET). It is hypothesized that oxygen groups on graphene oxide (GO) can act as a substitute for the stabilization process required to promote carbonization over cracking reactions, while the 2D graphene sheet promotes ordered development of aromatic clusters during graphitization. Thermo-gravimetric analysis (TGA) will be used as a measure of stabilization effectiveness. Raman spectroscopy will quantify graphene lateral spacing La across the carbonization temperature range along with amorphous and molecular content to track carbonization progress. Polarized light microscopy (PLM) will visualize pre-graphitic domains, quantified by image analysis to be developed in this project. Wide angle X-ray scattering will gauge aromatic domain growth at pre-graphitic (pre-crystalline) stages. Upon emergence of graphitic structure, standard X-ray diffraction (XRD) will be used to determine crystal lattice parameters d002, La, Lc and graphitization index g. A sequence of experiments will be conducted to collectively characterize the level of graphitization with GO oxygen content and graphene (GR) sp2 area and peripheral length, to validate reactive force field (ReaxFF) molecular dynamics simulations. Transmission electron microscopy (TEM) and selected area electron diffraction (SAED) will provide localized measures of graphitic quality and microscopic uniformity at the nanoscale. Electrical conductivity will assess crystallite connectedness via impedance spectroscopy using a Randall circuit model. A potential implication of the GO stabilizer is that the rate of graphitization will increase, thereby realizing energy savings and CO2 reduction.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.

拟议的研究旨在将消费塑料废物升级为用于电动汽车和可再生能源存储的高价值石墨碳。目前，石油和煤炭是锂离子电池中使用的石墨碳的前体，这些来源是不可再生的，需要大量能源。该研究计划将测试以下假设：与天然石墨相比，塑料废物具有更高的纯度和均匀性，因此可作为石墨烯的优质原料。改善回收经济，增加回收基础设施投资，增加回收劳动力，同时减少温室气体排放并提高公众的回收意识，这种升级回收方法可以回收塑料材料的能源成本，同时将碳作为固体捕获。作为新的“资源”，塑料废物将消除作为原料的石油和煤炭，并取代天然石墨的开采。升级回收塑料废物可以改变塑料循环经济，从而减少塑料污染，促进可持续发展，并为循环碳经济开辟一条新途径。外展工作包括a) 通过暑期实习增加科学和工程研究领域女性的多样性，b) 通过为期一周的科学营促进 K-12 STEM；c) 课外活动以及 d) 通过 YouTube 视频进行公开传播。将消费塑料废物升级为用于电动汽车和可再生能源存储的高价值石墨碳，解决了形成石墨碳的挑战。来自各种废塑料原料：高脂肪族（氢）含量（LDPE）和高氧含量（PET）人们再次认识到，氧化石墨烯（GO）上的氧基团可以作为促进碳化而不是裂解所需的稳定过程的替代品。反应，而二维石墨烯片在石墨化过程中促进芳香族簇的有序发展，将用作拉曼光谱的测量。量化整个碳化温度范围内的石墨烯横向间距 La 以及无定形和分子含量，以跟踪碳化进度。 偏光显微镜 (PLM) 将通过本项目中开发的广角 X 射线图像分析来可视化预图形域。散射将测量石墨前（结晶前）阶段的芳香域生长。在石墨结构出现后，将使用标准 X 射线衍射 (XRD) 来确定晶体。晶格参数 d002、La、Lc 和石墨化指数 g 将进行一系列实验，以共同表征 GO 氧含量和石墨烯 (GR) sp2 面积和周长的石墨化水平，以验证反作用力场 (ReaxFF) 分子。动力学模拟。透射电子显微镜（TEM）和选区电子衍射（SAED）将提供纳米级石墨质量和微观均匀性的局部测量。使用 Randall 电路模型通过阻抗谱实现微晶连接 GO 稳定器的潜在影响是石墨化率将会提高，从而实现节能和二氧化碳减排。该奖项反映了 NSF 的法定使命，并通过评估被认为值得支持。利用基金会的智力优势和更广泛的影响审查标准。