Establishing Liquid Crystals of Boron Nitride Nanotubes for Aligned Assemblies

建立用于对齐组件的氮化硼纳米管液晶

• 批准号: 2118416
• 负责人: Geyou Ao
• 金额: $ 35.39万
• 依托单位: Cleveland State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2118416&HistoricalAwards=false
• 关键词: Establishing; Liquid; Crystals; Boron; Nitride

Manufacturing strong and multifunctional nanomaterial-based films and fibers with improved alignment and properties enables many applications, including thermal management materials and protective fabrics. Lyotropic liquid crystals of nanomaterials with long-range order and fluidity are recognized as a promising precursor to produce solid assemblies with improved alignment and performance. This award supports fundamental research to provide the framework for establishing liquid crystals of boron nitride nanotubes – a lightweight nanomaterial with excellent thermal conductivity while being an electrical insulator. These material properties meet the critical need for manufacturing electrically insulating thermal interface materials for the next generation electronics and solar cells as well as high strength fibers for protective textiles. Aligned assemblies from this new material system are desirable for a wide array of applications from electronics, energy, aerospace, defense, to thermal packaging industries. Therefore, results from this research will benefit the U.S. economy and society. This research involves several disciplines including manufacturing, liquid crystal science, nanotechnology, and engineering. The multidisciplinary approach will simultaneously advance scientific discovery and a broadly inclusive, innovative, next-generation science and engineering workforce.The liquid crystals of boron nitride nanotubes for manufacturing aligned assemblies have not yet been achieved. This research is to fill the knowledge gap on the liquid crystalline phase behavior and the controlled assembly of boron nitride nanotube films and fibers with ordered structures for performance improvement. The cellulose nanocrystal matrix – a renewable and low-cost nanomaterial that is known to form chiral nematic liquid crystals – will be utilized as a structural template for forming liquid crystals of boron nitride nanotubes. Additionally, stable liquid dispersions of boron nitride nanotubes will be achieved by noncovalent complexation with biopolymers. This approach will preserve the intrinsic properties of nanotubes and further stabilize them in cellulose nanocrystal dispersions. The phase transition of liquid crystals will be investigated by rheology and optical microscopy and the assembled films and fibers will be characterized by various imaging techniques, mechanical testing, and thermal conductivity measurements. Combined, this research will test the broad hypothesis that lyotropic, chiral nematic liquid crystals can be obtained from the cellulose nanocrystal-templated nanotube system and the ordered liquid crystalline structures can be translated into solid assemblies for property enhancement, thus establishing the structure-processing-property relationships of the new nanomaterial system.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.

制造具有改进的对齐和性能的强大和多功能基于纳米材料的膜和纤维可实现许多应用，包括热管理材料和受保护的织物。具有远距离顺序和流动性的纳米材料的裂解液晶体被认为是产生具有改善对齐和性能的固体组件的承诺前体。该奖项支持基本研究，以提供建立硝酸硼纳米管的液晶框架，这是一种轻巧的纳米材料，具有出色的导热率，同时是电气绝缘体。这些材料特性满足制造下一代电子和太阳能电池的电绝缘界面材料以及保护纺织品的高强度纤维的关键需求。从电子，能源，航空航天，防御到热包装行业的各种应用程序，都需要从这个新材料系统进行对齐的组件。因此，这项研究的结果将使美国经济和社会受益。这项研究涉及几个学科，包括制造，液晶科学，纳米技术和工程。多学科的方法将简单地推进科学发现，并成为广泛包容的，创新的，下一代的科学和工程劳动力。尚未实现用于制造组件的硝酸硼纳米管的液晶。这项研究是为了填补有关液晶相行为的知识差距以及氮化硼纳米管膜的受控组装和具有有序结构的纤维，以改善性能。纤维素纳米晶体基质（一种可再生且低成本的纳米材料形成手性列液晶）将被用作形成硝化碳氮化物纳米管的液晶的结构模板。此外，通过与生物聚合物非共价络合，将实现氮化硼纳米管的稳定液体分散体。这种方法将保留纳米管的内在特性，并在纤维素纳米晶体分散体中进一步稳定它们。液晶的相变将通过流变学和光学显微镜研究，并且组装的膜和纤维将以各种成像技术，机械测试和导热率测量来表征。 Combined, this research will test the broad hypothesis that lyotropic, chiral nematic liquid crystals can be obtained from the cellulose nanocrystal-templated nanotube system and the ordered liquid crystalline structures can be translated into solid assemblies for property enhancement, thus establishing the structure-processing-property relationships of the new nanomaterial system.This award reflects NSF's statutory mission and has been使用基金会的智力优点和更广泛的影响标准，认为通过评估被认为是宝贵的支持。