EAGER: Intrinsically Ferromagnetic Functional Cellulose Nanocrystals in Confinement

EAGER：限制中的本质铁磁功能纤维素纳米晶体

• 批准号: 1939289
• 负责人: Mohan Srinivasarao
• 金额: $ 26.25万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-15 至 2023-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1939289&HistoricalAwards=false
• 关键词: EAGER; Intrinsically; Ferromagnetic; Functional; Cellulose

Non-Technical AbstractNano-structured cellulose or "nanocellulose" is readily produced through the breakdown of cellulose fibers, which are ubiquitous in our surroundings. One form of nanocellulose, namely, cellulose nanocrystals (CNCs), are high aspect ratio, highly crystalline materials, whose mechanical properties have made them attractive candidates for a wide range of applications including polymer composites and personal care products. The high aspect ratio of CNCs imparts them with the ability to self-assemble into liquid crystalline (LC) phases which provide opportunities for the development of new sensors and optical technologies. This proposal explores the design and development of a class of functionalized CNCs, namely CNCs uniformly functionalized with earth abundant magnetic materials which will lead to the development of ferromagnetic alternatives. Low-cost, ferromagnetic materials based upon sustainable bio-derived materials could transform the world in which we live, creating opportunities for new optical devices that could be manipulated in the presence of magnetic fields, impacting technologies ranging from sensors to optical signaling and transmission. The proposed research provides opportunities for the integration of research and education in technologies of societal significance. In addition, students engaged in the program will be exposed to a multidisciplinary experience at the intersection of chemical engineering, materials science, materials chemistry and materials physics. The student participants will be cross-trained and where necessary will further expand their knowledge and experience through relevant additional collaborations.Technical AbstractThe propensity of cellulose nanocrystals (CNCs) to organize into liquid crystalline structures offers opportunities for the design of entirely new classes of sustainable materials that exhibit phenomena that may enable new classes of optical devices. Functional CNCs, in particular, offer opportunities for creating not only new classes of optical devices, but also magneto-optical devices. This project will explore the design of functionalized, intrinsically magnetic CNCs whose structure could be influenced by the presence of electrical and/or magnetic fields. It is proposed that a thin conformal layer of metals such as Ni, Cr, and Fe on the surface of the biomaterial will lead to creation of a cholesteric phase, which will provide a demonstration of an ordered fluid possessing spontaneous magnetization in the absence of an external magnetic field. Such a discovery will create entirely new research directions and opportunities for technology development. In an effort to understand and exploit the range of opportunities, ferromagnetic cholesteric liquid crystals will be created and the coupling between the magnetic moment and director of the chiral nematic phase will be investigated. In addition, the self-assembly of the functional CNCs in confined geometries, specifically spherical and cylindrical geometries will be interrogated. These studies will be combined with investigations into confinement of the liquid crystalline phase in thermoresponsive, spherical microgel particles. The proposed investigation will afford new, sustainable advanced optical technologies.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.

纳米结构纤维素或“纳米纤维素”容易通过纤维素纤维的分解产生，纤维素纤维在我们的环境中无处不在。纳米纤维素的一种形式，即纤维素纳米晶体（CNC），是高纵横比、高度结晶的材料，其机械性能使其成为包括聚合物复合材料和个人护理产品在内的广泛应用的有吸引力的候选者。高纵横比的CNCs赋予它们自组装成液晶（LC）相的能力，这为新传感器和光学技术的发展提供了机会。 该提议探索了一类功能化的CNCs的设计和开发，即用地球丰富的磁性材料均匀功能化的CNCs，这将导致铁磁替代品的开发。基于可持续生物衍生材料的低成本铁磁材料可以改变我们生活的世界，为可以在磁场存在下操纵的新光学设备创造机会，影响从传感器到光学信号和传输的技术。拟议的研究为具有社会意义的技术的研究和教育的整合提供了机会。此外，参与该计划的学生将接触到化学工程，材料科学，材料化学和材料物理学交叉的多学科经验。 学生参与者将交叉培训，并在必要时将进一步扩大他们的知识和经验，通过相关的额外collaboration.Technical AbstractThe倾向的纤维素纳米晶体（CNCs）组织成液晶结构提供了机会，设计全新的类的可持续材料，表现出的现象，可能使新的类的光学器件。特别是，功能性CNC不仅为创建新的光学器件类别提供了机会，而且还为磁光器件提供了机会。该项目将探索功能化的，固有磁性的CNCs的设计，其结构可能会受到电场和/或磁场的影响。有人提出，薄保形层的金属，如镍，铬，和铁的表面上的生物材料将导致创建一个有序相，这将提供一个演示的有序流体具有自发磁化在没有外部磁场。这一发现将为技术发展创造全新的研究方向和机会。在努力理解和利用的机会范围内，铁磁液晶将被创建和手性液晶相的磁矩和导演之间的耦合将被调查。此外，自组装的功能性CNCs在有限的几何形状，特别是球形和圆柱形的几何形状将被询问。这些研究将结合调查限制的液晶相的温度响应，球形微凝胶颗粒。该奖项反映了NSF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。