ARI: Synthesizing Conjugated Polymers with High Scintillation Light Yield

针对潜在的放射性和核威胁的有效应对措施要求广泛部署具有高灵敏度同位素识别辐射源的传感器。提供伽马射线光谱和中子与伽马鉴别的探测器是核传感的关键。该项目旨在开发一种新的聚合物闪烁体，其具有与无机晶体相当的高灵敏度，同时保持极低的生产成本。这种制冷机可以在全国范围内广泛使用吗？的港口和大型公共场所，以遏制安全威胁。 目前的辐射探测器大多基于单晶无机半导体或晶体管，它们都不能满足高灵敏度、能量分辨率、可现场性和低成本的苛刻要求。该提案旨在开发一种基本的方法来合成具有与无机单晶闪烁器相当的闪烁性能的共轭聚合物单块。该整料可以在模具中通过热固性聚合以极低的生产成本合成。 该研究将研究具有大三重态能级的共轭化合物和聚合物作为主体材料，将单重态和三重态激子转移到蓝色磷光荧光体中，以获得高闪烁光产率。熔融溶液的共聚将被研究作为一种有效的技术来合成大尺寸的透明整料与均匀分布的添加剂和可忽略的聚集。该项目的目标是展示透明共轭聚合物单片，目标光产额为100，000/MeV，是目前商业塑料发光器的近10倍。还将研究对中子粒子和伽马射线具有高吸收截面的敏化剂，以获得高灵敏度和中子-伽马脉冲鉴别。这项工作是基于对透明聚合物单片的初步研究，其光产率已经是商业塑料闪烁体的4.6倍。所提出的具有高闪烁光产额和低生产成本的共轭聚合物闪烁器将开辟对国土安全、医学成像和空间探索重要的广泛的新应用。研究结果将迅速传播，项目中开发的技术将被转让，以便迅速商业化。该项目将对从高中到博士生的学生的教育和辅导产生影响。教育和培训具有材料科学和核材料相互作用双专业的本科生和研究生是项目活动的一部分。研究生和博士后研究员将有机会在合作的国家实验室实习，以获得辐射检测的第一手经验。

1348403 (Pei) Effective counter measures against potential radioactive and nuclear threats call for a wide-spread deployment of sensors with high-sensitivity isotopic identification of radiation sources. Detectors providing gamma ray spectroscopy and neutron and gamma discrimination are keys in nuclear sensing. This project aims to develop a new polymer scintillator that exhibits high sensitivity comparable to inorganic crystals while maintaining an extremely low production cost. The scintillators could be widely deployed at the nation?s ports and large public venues to deter security threats. Current radiation detectors are mostly based on single crystal inorganic semiconductors or scintillators, none of which satisfy the demanding requirements of high sensitivity, energy resolution, fieldability, and low cost. This proposal aims at developing a fundamental approach to the synthesis of conjugated polymer monoliths with scintillation performance comparable to inorganic single crystal scintillators. The monoliths can be synthesized by thermosetting polymerization in a mold at extremely low production cost. The research will investigate conjugated compounds and polymers with large triplet energy levels as the host material to transfer both singlet and triplet excitons to a blue phosphorescent fluor for high scintillation light yield. Copolymerization of molten solutions will be studied as an effective technique to synthesize bulk-size transparent monoliths with uniform distribution of additives and negligible aggregation. The objective of the project is to demonstrate transparent conjugated polymer monoliths with a target light yield of 100,000/MeV, an improvement of almost 10 times that of current commercial plastic scintillators. Sensitizing agents with high absorption cross-sections for neutron particles and gamma rays will also be investigated for high sensitivity and neutron-gamma pulse discrimination. The work is based on preliminary research on transparent polymer monoliths with a measured light yield that is already 4.6 times that of a commercial plastic scintillator. The proposed conjugated polymer scintillators with high scintillation light yield and low production cost will open up a wide range of new applications important to homeland security, medical imaging, and space exploration. The research findings will be rapidly disseminated, and the technology developed in the project is targeted to be transferred for rapid commercialization. The project will have impact on education and mentoring of students from high schools up to doctoral candidates. Education and training of undergraduate and graduate students with dual specialties of materials science and nuclear-material interactions is part of the project activities. Graduate students and postdoctoral fellows will have the opportunity to intern in the collaborating national labs to gain firsthand experience with radiation detection.