GOALI: Tomography and X-ray Interferometry of Flame Retardants and Additive Manufacturing

GOALI：阻燃剂和增材制造的断层扫描和 X 射线干涉测量

• 批准号: 1610655
• 负责人: Leslie Butler
• 金额: $ 36万
• 依托单位: Louisiana State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-15 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1610655&HistoricalAwards=false
• 关键词: GOALI; Tomography; ray; Interferometry; Flame

With this award, the Chemical Measurement and Imaging Program in the Division of Chemistry and the Grant Opportunities for Academic Liaisons with Industry (GOALI) program in the Division of Industrial Innovation and Partnerships (IIP) are supporting Professor Les Butler at Louisiana State University (LSU) and Dr. Jonathan McCarney at Albemarle Corporation to develop new X-ray imaging methods to assess the performance of flame retardants (FR) in polymers (plastics). Currently, flame retardants are assessed with methods such as the Underwriter Laboratory Standard for Tests for Flammability of Plastic Materials for Parts in Devices and Appliances (UL 94) using a bunsen burner, a stopwatch, and a cotton pad. The UL method is practical, but does not provide a chemical/physical insight into the effectively development of new flame retardants. The approach under development in the labs of Professor Butler and Dr. McCarney evaluates flame retardants by fast recording 2-D x-ray images (i.e. movies) during the burning period. The resulting movie enables direct visualization of chemical and physical processes, such as particle dissolution, gas bubble generation, the flow of the melting plastic, char-layer development, and micro-cracks in the char layer. In addition, the x-ray images provide quantitative information for more in-depth performance evaluations of new flame retardant materials relative to traditional tests. Beyond FR testing, both groups are also applying this new x-ray imaging technique in 3-D printing where new flame retardant materials are incorporated into consumer objects. Professor Butler is actively engaged an outreach effort to science students through the NSF I-Corp program where the combination of non-destructive chemical testing, 3-D printing, and materials development provides many research and educational opportunities to graduate, undergraduate and local high school students. The software under development in the Butler group, in collaboration with the Advanced Photon Source, will be made available to the public through the TomoPy project, an open source tomography software package.The X-ray imaging method under development at LSU uses two new grating-based interferometers recently constructed by the Butler team. The interferometers is operated in two modes: single-shot for speed, and stepped-grating for better image quality. The single-shot interferometry provides absorption, phase, and scattering imaging modalities during the measurements and its fast speed in image collection enables X-ray movie recording of flame retardant in action in a modified UL 94 test and direct observation of the performance of new-generation flame retardants. The same imaging methods is applied to fused deposition modeling (FDM), also known as 3-D polymer printing. The goal is development of procedures for assessing flame retardant impact on the quality of the 3-D print where x-ray movies show in situ fused deposition modeling of filaments composed of flame retardant/polymer blends to assess compatible temperature, flow, and printhead speeds. The knowledge is then to be used in exploring new options for 3-D structure of flame retardants in the printed object.

有了这个奖，化学部的化学测量和成像项目以及工业创新和合作部的学术界与工业界联系的资助机会项目正在支持路易斯安那州立大学的莱斯·巴特勒教授和Albemarle公司的乔纳森·麦卡尼博士开发新的X射线成像方法，以评估阻燃剂的性能聚合物（塑料）。目前，使用本生灯、秒表和棉垫，用诸如用于装置和器具中的部件的塑料材料的可燃性测试的保险商实验室标准（UL 94）的方法评估阻燃剂。 UL方法是实用的，但不能提供有效开发新阻燃剂的化学/物理见解。Butler教授和McCarney博士的实验室正在开发的方法通过在燃烧期间快速记录2-D X射线图像（即电影）来评估阻燃剂。 由此产生的电影能够直接可视化化学和物理过程，例如颗粒溶解，气泡生成，熔融塑料的流动，炭层发展和炭层中的微裂纹。 此外，X射线图像还提供了定量信息，用于对新阻燃材料进行更深入的性能评估。除了阻燃测试之外，这两个小组还将这种新的X射线成像技术应用于3D打印，将新的阻燃材料融入消费品中。巴特勒教授通过NSF I-Corp计划积极参与科学学生的外展工作，其中非破坏性化学测试，3D打印和材料开发的结合为研究生，本科生和当地高中生提供了许多研究和教育机会。Butler团队与Advanced Photon Source合作开发的软件将通过TomoPy项目向公众提供，TomoPy项目是一个开放源代码的层析成像软件包。LSU正在开发的X射线成像方法使用Butler团队最近建造的两个新的光栅干涉仪。干涉仪有两种工作模式：单次扫描模式以提高速度，步进光栅模式以提高图像质量。单次激发干涉法可在测量过程中提供吸收、相位和散射成像模式，其快速的图像采集速度使其能够在修改的UL 94测试中记录阻燃剂的X射线电影，并直接观察新一代阻燃剂的性能。 同样的成像方法也应用于熔融沉积成型（FDM），也称为3D聚合物打印。目标是开发评估阻燃剂对3D打印质量影响的程序，其中X射线电影显示由阻燃剂/聚合物共混物组成的长丝的原位熔融沉积建模，以评估兼容的温度，流量和打印头速度。然后，这些知识将用于探索打印物体中阻燃剂3D结构的新选择。