Magnetic Oxide Nanoparticles Templated By the Self-Assembly of Block Copolymers

cts - 0347319 p。该更新提案的目的是将半金属纳米颗粒纳入微相分离二嵌段共聚物的自组装域，并合成具有改进磁性的球形和圆柱形功能纳米结构。降冰片烯及其衍生物的开环复分解聚合（ROMP）是合成窄多分散性金属功能化嵌段共聚物的有效途径。嵌段共聚物微相分离可以有效地用作模板，将无机材料的纳米颗粒限制在一个纳米畴内。嵌段共聚物中畴结构的自组装性质允许控制10-500埃纳米颗粒的形状、大小和分散。我们计划在可控条件下精心合成特定的聚合物模板纳米复合化合物家族，以块状和薄膜形式，建立它们的结构，化学化学计量和有序度，然后将磁性能与结构化学参数相关联。传统中子散射和磁性中子散射的独特结合将用于建立聚合物自组装与磁性之间的关系。将对广泛的铁磁体进行研究，这些铁磁体将被纳入自组装的聚合物纳米域，包括已知的半金属体系，如CrO2，尖晶石，如NiFe2O4和层状铁氧体，如Ba2Fe6O19。拟议研究的广泛影响涉及纳米系统中的磁性，这是基础科学中一个引人入胜的话题，也与微电子技术的最新技术进步密切相关，因为磁体是电子设备的重要部件。随着微电子系统尺寸的不断缩小和对小尺寸元器件需求的增加，了解和控制纳米颗粒等小尺寸磁体的磁性变得越来越重要。纳米晶氧化尖晶石对磁性的基础研究很有兴趣，在高频器件、存储核心和磁记录介质中有许多应用。这项研究将培养新一代的本科生和研究生，并在一个对聚合物和微电子工业未来技术发展至关重要的领域建立研究基础设施。教育活动包括本科生和研究生的教学、研究生的指导、本科生参与研究和指导的各种机会，以及互动网页的开发。中学教师和学生也将通过RET和REU补品接触到纳米颗粒研究的各个方面，如果该提案得到资助，将要求这些补品。

CTS-0347319P. Kofinas, University of Maryland College ParkThe purpose of this renewal proposal to a previously obtained CAREER award, is to incorporate half metallic nanoparticles into the self-assembled domains of microphase separated diblock copolymers and to synthesis spherical and cylindrical functional nanostructures exhibiting improved magnetic properties. Ring-opening metathesis polymerization (ROMP) of norbornene and its derivatives has proved to be a very effective way of synthesizing metal-functionalized block copolymers of narrow polydispersity. The block copolymer microphase separation can be effectively used as a template to confine nanoparticles of inorganic materials within one of the nanodomains. The self-assembled nature of the domain structure in block copolymers allows control over the shape and size and dispersion of 10-500 angstrom nanoparticles.We plan to carefully synthesize specific families of polymer templated nanocomposite compounds in bulk and thin-film form under controlled conditions, establish their structure, chemical stoichiometry, and degree of order, and then correlate the magnetic properties with the structural-chemical parameters. A unique combination of conventional and magnetic neutron scattering will be used to establish the relationship between the polymer self-assembly and the magnetic properties will be conducted for a broad class of ferromagnets that will be incorporated into the self-assembled polymer nanodomains including known half-metallic systems such as CrO2, spinels such as NiFe2O4 and layered ferrites such as Ba2Fe6O19.The broader impacts of the proposed research relate to magnetism in nanometer systems, a fascinating topic in fundamental science, which is also closely related to the advancement of the state-of-the-art technologies in microelectronics since magnets are vital components of electronic devices. As the dimension of microelectronic system continually shrinks and demands for small-dimension components increase, the understanding and controlling magnetic properties of small length scale magnets such as nanoparticles becomes increasingly crucial. Nanocrystalline oxide spinels are of interest both for fundamental studies in magnetic properties that have found numerous applications in high frequency devices, memory cores and magnetic recording media.The pursuit of this research will result in training of a new generation of undergraduate and graduate students and build research infrastructure in an area of vital importance to future technical developments in the polymer and microelectronic industries. The education activities to be undertaken include undergraduate and graduate teaching, graduate student advising, and various opportunities in undergraduate research involvement and mentoring, as well as the development of an interactive web page. Middle school teachers and students will also be exposed to aspects of nanoparticle research through RET and REU supplements, which will be requested if this proposal is funded.