Inter-American Materials Collaboration: Surface Structure and Metal Uptake of Apatite Films and Particles

美洲材料合作项目汇集了美国西北大学（NU）的D. Ellis和巴西巴西经济研究中心的A. Malta Rossi领导的两个小组。研究人员对羟基磷灰石（HAP）和相关磷灰石结构的表面结构和金属离子吸收进行了理论和实验分析，包括纳米颗粒和薄膜形态。理论研究进行了化学计量和缺陷状态，使用混合经典和量子方法开发的应用于复杂材料。材料是在北方大学使用溅射和蒸发技术制备的，可以严格控制化学成分和表面纹理。对纹理表面进行光谱分析，并与从溶液中沉淀制备的纳米颗粒进行比较，这些都是与巴西巴西经济研究中心（Centro Brasileiro de Pesquisas Fisicas）的人员合作进行的。解决的问题在于生物医学工程，化学，材料科学和物理之间的接口。成功的结果将对三个主要领域产生影响：(i)更好地了解人体骨骼和牙齿中重金属的吸收和保留，由于环境中铅的积累尤其重要；（ii）可能改进废水和土壤处理的材料和策略，以消除或防止重金属污染物的迁移；（iii）提高对基本化学过程的了解，这是开发环境友好型化学处理的磷灰石基催化剂所必需的。该奖项由材料研究部、国际科学与工程办公室以及数学和物理科学理事会的多学科活动办公室提供支持。

This Inter-American Materials Collaboration brings together two groups led by D. Ellis at Northwestern University (NU) in the US and A. Malta Rossi at the Centro Brasileiro de Pesquisas Fisicas in Rio de Janeiro, Brazil. The investigators carry out theoretical and experimental analyses of surface structure and metal ion uptake of hydroxyapatite (HAP) and related apatite structures, in nanoparticulate and thin film morphologies. Theoretical studies are made for both stoichiometric and defected states, using hybrid classical and quantum methodologies developed at NU for applications to complex materials. Materials are prepared at NU using sputtering and evaporation techniques that permit close control over chemical composition and surface textures. Spectroscopic analyses of textured surfaces and comparison with nanoparticulates prepared by precipitation from solution, are carried out in collaboration with personnel at Centro Brasileiro de Pesquisas Fisicas at Rio de Janeiro and elsewhere in Brazil.The problem addressed lies at the interface between Biomedical Engineering, Chemistry, Materials Science, and Physics. Successful outcomes will have impact on three main areas: (i) a better understanding of heavy metal uptake and retention in human bone and tooth, of particular importance due to lead accumulation in the environment, (ii) possibly improved materials and strategies in treatment of wastewaters and soils, to remove or prevent migration of heavy metal contaminants, (iii) improved understanding of basic chemical processes, needed for development of apatite-based catalysts for environmentally friendly chemical processing. This award is supported by the Division of Materials Research, the Office of International Science and Engineering, and the Office of Multidisciplinary Activities in the Directorate for Mathematical and Physical Sciences.