CAREER: Directed Nanoparticle Growth by Oriented Aggregation and Elucidating the Link between Reactivity and Particle Size, Shape, and Microstructure

明尼苏达大学双城分校的R. Lee Penn教授在分析和表面化学项目以及地质和古生物项目的支持下，通过定向聚集机制研究晶体、纳米级、过渡金属氧化物和氢氧化物的形成。这种机制包括通过特定晶体平面的附着来组装初生晶体。重点是通过操纵晶体表面性质来控制取向聚集。除了纳米颗粒的生长外，还通过溶解和氧化还原反应的研究来探索这些材料的化学性质。粒子结构主要通过x射线衍射、电子显微镜和光子相关光谱测量来确定。佩恩教授还在为中学生和科学教育者开发一个项目，旨在提高人们对原子水平上物质结构的认识。通过以晶体生长和表征为中心的实验练习，帮助学生和教育者理解材料的宏观特性和底层原子水平结构之间的关系。通过溶解和氧化还原反应对无机氧化物晶体生长和晶体分解的研究提供了通过大气和地质化学影响自然环境的过程的见解。该教育计划旨在为初中生和教育工作者提供学习机会，以提高对大块材料性质和原子水平结构之间关系的认识。

Professor R. Lee Penn of the University of Minnesota-Twin Cities is supported by the Analytical and Surface Chemistry Program and the Geology and Paleontology program to investigate the formation of crystalline, nanometer-scale, transition metal oxides and hydroxides through the mechanism of oriented aggregation. This mechanism involves the assembly of primary crystals by attachment through specific crystallographic planes. Emphasis is on the control of orientated aggregation through manipulation of crystal surface properties. In addition to nanoparticle growth, chemical properties of these materials are probed through the study of dissolution and redox reactions. Particle structure is determined primarily by x-ray diffraction, electron microscopy and photon correlation spectroscopy measurements. Professor Penn is also developing a program for middle school students and science educators designed to enhance awareness of the structure of materials at the atomic level. Laboratory exercises that center on crystal growth and characterization are implemented to assist students and educators in understanding relationships between the macroscopic properties of materials and the underlying atomic level structure. Studies of inorganic oxide crystal growth and crystal decomposition through dissolution and redox reactions is providing insights into processes that affect the natural environment through atmospheric and geological chemistry. The education plan is providing learning opportunities for middle school age students and educators to enhance awareness of relationships between bulk materials properties and atomic level structure.