CAREER:Engineered Nanoscopic Objects via Controlled Creation and Rearrangement of Amorphous Nanoparticles

[0846586 . nairintellectual Merit]本职业规划的长期目标是为设计和反应工程的复杂形态和结构的超小型金属氧化物物体开发和展示一个通用的使能原则框架。具体来说，PI建议理解和操纵控制液相工程的新机制和热力学，这类独特的单壁混合氧化物纳米管（长度特别小，为20-100纳米，直径2-4纳米）和单壁纳米壳（直径5纳米）都具有复杂和有序的内部结构。在非常小的长度尺度上设计纳米级金属氧化物物体的形状、大小、结构和组成的能力——只需要最少数量的物质——是非常有吸引力的（但迄今为止还难以实现）。许多新兴的应用可以利用这些物体独特的形状、大小和结构复杂性所产生的新颖和急剧可调的电子、光学、催化、传输和机械性能。这样的发展将强调先进的化学处理方法在纳米科学和技术方面的全部潜力，并且可以克服当前材料和工艺所施加的限制。PI最近的工作已经提出了一种长期的分子工程策略（概括为“无定形纳米颗粒凝聚和重排”），它比目前的模板或催化方法具有内在的优势，并产生具有复杂结构的超小型金属氧化物物体。在五年的CAREER资助期间，PI建议通过材料合成，先进的液相和固态表征工具，分子模拟和分析理论的独特组合，阐明控制单壁金属氧化物纳米管和纳米壳形成的第一个广义机制和热力学框架。在这一阶段的末期和长期内，他将运用这一框架来指导新型纳米物体的工程设计，这些纳米物体可以影响不同研究人员所追求的更广泛的技术，也会影响基于氧化物材料的自下而上纳米技术的当前思维。这个框架对于理解自然过程也有潜在的意义，这些过程的假设机制与他的方法有几个共同的特征，比如二氧化硅和其他无机氧化物的生物矿化，以及自然环境中有序物体（如纳米管、纳米壳和原沸石）的进化。更广泛的影响：这一职业规划，以及近年来PI建立的基础设施，将有效地整合从高中生到教授等多个层面的研究和教育，并对许多人产生长期影响。这项职业补助金将成为佐治亚理工学院（GT）教师与Gwinnett数学科学与技术学院（GSMST）之间合作伙伴关系的基石，GSMST是一所专注于stem的特许高中。PI、他的研究生和本科生、访问学生、GSMST教师和GT K-12外展专家将合作开发一套实验室和课堂模块，这些模块将集成到有关纳米技术和替代能源的新颖高中课程中。这种合作方式——正在通过一个试点项目开发——每年将使大约150名高中生接触到尖端的工程和科学学习；保留和鼓励这些学生从事STEM职业；为GT和GSMST的参与者创造一种愉快和富有成效的体验，其活动水平不会影响研究生产力。PI将通过将这些令人兴奋的研究见解纳入他的纳米级化学工程本科/研究生课程，将其转化为GT课堂。该项目涉及五名GT本科生和五名外部学生，并与NSF-SURE计划合作，该计划每年夏天将少数民族学生带到GT进行研究。研究结果将通过出版物和简报传播，并有可能继续通过科学和技术新闻媒介向一般公众传播。总体而言，这一职业规划旨在帮助建立一支在技术和科学研究、教育和应用方面训练有素的骨干队伍；他们可以很容易地被美国工业（包括不断发展的纳米技术工业）和学术界吸收。

0846586NairIntellectual Merit: The long-term objective of this career plan is to develop and demonstrate a generalized enabling framework of principles for the design and reaction engineering of ultra-small metal oxide objects of complex morphology and structure. Specifically, the PI proposes to understand and manipulate the novel mechanisms and thermodynamics that govern the liquid-phase engineering of a unique class of single-walled mixed oxide nanotubes (with exceptionally small lengths of 20-100 nm and diameters 2-4 nm) and single-walled nanoshells (with diameter 5 nm), all with complex and ordered internal structures. The ability to engineer the shape, size, structure, and composition of nanoscopic metal oxide objects at very small length scales - using only the minimum quantity of matter necessary - is highly attractive (but thus far elusive). A number of emerging applications could exploit the range of novel and drastically tunable electronic, optical, catalytic, transport, and mechanical properties arising from the unique shape, size, and structural complexity of these objects. Such a development would underscore the full potential of advanced chemical processing approaches for nanoscale science and technology, and can overcome limits imposed by current materials and processes. The PI's recent work has led to a proposed long-term molecular engineering strategy (summarized as 'amorphous nanoparticle condensation and rearrangement') that offers intrinsic advantages over current templating or catalytic approaches, and produces ultra-small metal oxide objects with complex structures. During the five-year CAREER grant, the PI proposes to elucidate the first generalized mechanistic and thermodynamic framework governing the formation of single-walled metal oxide nanotubes and nanoshells, through a unique combination of materials synthesis, advanced liquid-phase and solid-state characterization tools, molecular simulation, and analytical theory. Towards the end of this period and in the longer term, he will apply this enabling framework to guide the engineering of new classes of nanoscopic objects that can impact a wider range of technologies pursued by diverse researchers and also impact current thinking in bottom-up nanotechnology based on oxide materials. This framework also has potential implications in understanding natural processes whose hypothesized mechanisms have several common features with his approach, such as the biomineralization of silica and other inorganic oxides, and the evolution of ordered objects (e.g., nanotubes, nanoshells, and proto-zeolites) in natural environments. Broader Impacts: This career plan, along with infrastructure built by the PI in recent years, will effectively integrate research and education at multiple levels - from the high school student to the professor - and create long-term impact on a number of people. This CAREER grant will be a cornerstone of a partnership between Georgia Tech (GT) faculty and the Gwinnett School of Mathematics Science and Technology (GSMST), a STEM-focused charter high school. The PI, his graduate and undergraduate students, visiting students, GSMST teachers, and GT K-12 outreach experts will collaborate to develop a set of laboratory and classroom modules that will be integrated in novel high-school courses on Nanotechnology and Alternative Energy. This collaborative approach - under development via a pilot project - will expose a total of ~150 high school students per year to cutting-edge engineering and science learning; retain and encourage such students in pursuit of STEM careers; and create an enjoyable and productive experience for GT and GSMST participants with a level of activity that does not affect research productivity. The PI will translate the exciting research insights into the GT classroom by incorporating them into his undergraduate/graduate course in nanoscale chemical engineering. The project involves five GT undergraduates and five external students by collaboration with the NSF-SURE program which brings minority-group students to GT for research every summer. The results will be disseminated via publications and presentations, and also have continued potential for dissemination to the general public by the science and technology news media. Overall, this career plan is designed to help build a substantial cadre of well-trained personnel in technology and science research, education, and application; who can be readily absorbed by US industry (including the growing nanotechnology industry) and academia.