Functionalized Magnetic Nanoparticles as Polymerization Catalysts

建议标题：功能化磁性纳米粒子作为聚合催化剂建议编号：CTS-0553554主要研究人员：Christopher W.Jones研究所：佐治亚理工学院GA理工学院基于离散过渡金属络合物的单位均相聚合催化剂的出现在聚合物化学领域引发了一场革命。尽管这些新催化剂取得了很大的成功，但它们受到一个共同的问题的阻碍，即所有均相聚合催化剂都有一个共同的问题，即它们很难从产物聚合物中去除。在某些情况下，这对这项新技术在生物医学应用中的应用造成了严重的限制。磁性纳米粒子(直径10-50 nm)在聚合过程中作为催化剂的固体载体具有很大的潜力。该材料极小的颗粒尺寸提供了大的外表面积与体积比，允许在固体的外表面上都有巨大的催化活性中心密度，从而消除了阻碍多孔固体作为催化剂载体的所有颗粒内扩散限制。此外，纳米颗粒载体的磁性能力提供了一种通过使用外加磁场简单而有效地回收催化剂的方法，潜在地允许制备不含残余金属的聚合物。尖晶石铁氧体纳米粒子为设计和控制磁性能提供了一个极好的平台，以满足这些标准。特别是，钴尖晶石型铁氧体体系(Co1-xMxFe2O4，M=镁或锌，X=0 1)提供了各种潜在的有用载体，因为尖晶石型铁氧体纳米颗粒的磁性可以通过化学手段改变，并且它们的性能可以根据特定的应用进行优化。尖晶石铁氧体磁性纳米粒子将与硅烷功能化，以固定化聚合催化剂，其中催化剂回收可能是有益的。特别是，内酯聚合催化剂是一个关键的焦点。预计纳米颗粒载体也将是许多其他类型的固定化催化剂的理想载体，而不仅仅是聚合催化剂。几乎所有的商业消费品都将塑料和聚合物作为其结构中的关键成分。因此，该项目为聚合催化提供了一个潜在的新技术平台，有可能广泛影响到无数不同的领域。这个多学科项目汇集了几个关键技术领域，包括纳米技术、光谱学、表面化学、配位化学和聚合物科学。因此，它将极大地拓宽研究生的技术背景，化学和化学工程研究生之间的密切互动提供了在多学科团队环境中工作的宝贵经验，就像在典型的现代工业研发实验室中一样。这项研究的结果将逐渐应用到佐治亚理工学院新发起和不断发展的研究生和本科生纳米技术校园课程中，这两个PI都在其中发挥着关键作用。

AbstractProposal Title: Functionalized Magnetic Nanoparticles as Polymerization CatalystsProposal Number: CTS-0553554Principal Investigator: Christopher W. JonesInstitution: Georgia Tech Research Corporation GA Institute of TechnologyThe advent of single site, homogeneous polymerization catalysts based on discrete transition metal complexes has produced a revolution in the field of polymer chemistry. Despite all the successes of these new catalysts, they are hampered by one common problem that all homogeneous polymerization catalysts share they are difficult to remove from the product polymer. In some cases, this places severe limitations on this new technology for examples in biomedical applications. Magnetic nanoparticles (10-50 nm in diameter) have great potential for use as solid supports for catalysts in polymerization processes. The extremely small particle size of the material gives a large external surface area to volume ratio allowing for an enormous catalytic active site density all on the external surface of the solid, eliminating all intra-particle diffusional limitations that hamper porous solids as catalyst supports. Furthermore, the magnetic capability of the nanoparticulate support provides a way for simple and efficient recovery of the catalysts through the use of an applied magnetic field, potentially allowing for the preparation of polymers that are free of residual metal. Spinel ferrite nanoparticles offer an excellent platform for design and control of magnetic properties to satisfy these criteria. In particular, the cobalt spinel ferrite system (Co1-xMxFe2O4 with M = Mg or Zn and X = 0 1), offers a variety of potentially useful supports, as the magnetic properties of the spinel ferrite nanoparticles can be altered by chemical means and their properties can be optimized for specific applications. Spinel ferrite magnetic nanoparticles are to be functionalized with silanes to immobilize polymerization catalysts where catalyst recovery might be beneficial. In particular, lactone polymerization catalysts are a key focus. It is anticipated that the nanoparticle supports will be ideal for many other types of immobilized catalysts as well, not just polymerization catalysts. Nearly all commercial consumer products have plastics and polymers as key components in their construction. Thus, this project, in offering a potentially new technology platform for polymerization catalysis, has the possibility to broadly impact myriad different fields. The multi-disciplinary project brings together several key technology areas including nanotechnology, spectroscopy, surface chemistry, coordination chemistry and polymer science. Hence, it will greatly broaden the technical backgrounds of the graduate students involved, with the close interactions among graduate students in chemistry and chemical engineering offering the invaluable experience of working in a multidisciplinary team environment just as in a typical modern industrial research and development laboratory. The results from this research will trickle into Georgia Institute of Technology's newly initiated and evolving campus-wide courses on nanotechnology at both graduate and undergraduate levels, in which both PIs are playing key roles.