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Synthesis And Characterization Of Polymer Nanomaterials Using Controlled Radical Polymerization, Lei Wang

Theses and Dissertations

This research focuses on creating and investigating polymer/organic bound interfaces on nanoparticles with advanced architectures to tailor the properties of polymer nanocomposites for various applications. Reversible addition-fragmentation chain transfer (RAFT) polymerization and a toolbox of surface functionalization from the simple to the advanced were developed to prepare the polymer nanomaterials.

In the first part (Chapter 2), a variety of RAFT agents (xanthate, dithiocarbamate and trithiocarbonate) were used to mediate the polymerizations of several classes of free radical polymerizable monomers. These monomers consist of styrene, methyl acrylate, methyl methacrylate, vinyl acetate and isoprene, which have different activities and require different classes …

Synthesis And Characterization Of Cobalt Carbide Based Nanomaterials, Zachary Huba

Theses and Dissertations

Permanent magnets are used heavily for multiple applications in industry and current electronic technologies. However, the current permanent landscape is muddled by high cost of materials and insufficient magnetic or thermal properties. The primary focus of this dissertation work is the synthesis and optimization of a new permanent magnetic material, in the form of cobalt carbide nanomaterials. The optimization revolved around controlling the crystal phase and particle shape of synthesized cobalt carbide particles; these parameters have significant impact on the observed magnetic properties of magnetic nanoparticles. Co₃C was identified to be the preferred crystal phase, leading to better …

Spin And Orbital Moments And Magnetic Order In Fe3o4 Nanoparticle Assemblies, Yanping Cai

Theses and Dissertations

Fe3O4 magnetic nanoparticles of 5 to 11 nm in size were prepared by organic methods. Particle size was analyzed by both X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) techniques. Zero Field Cooling (ZFC) / Field Cooling (FC) and magnetization loop measurements were recorded by VSM, and they confirmed superparamagnetic behavior in the sample. The blocking temperature is found to be in the range of 30 K ~ 170 K. It has a dependence on the particle size. ZFC / FC curves also indicate the presence of magnetic coupling between particles. X-ray Magnetic Circular Dichroism (XMCD) measurements of these nanoparticles …