Graduation Semester and Year
2017
Language
English
Document Type
Dissertation
Degree Name
Doctor of Philosophy in Physics and Applied Physics
Department
Physics
First Advisor
Ali R Koymen
Abstract
The aim of this thesis is to explore the novel cost-effective synthesis technique to develop nanostructured materials and investigate their structural and magnetic properties. Nanomaterials were synthesized by a plasma discharge between desired metal electrodes in the cavitation field of an organic solvent. Multifunctional core-shell magnetic nanoparticles of 3d transition elements (Fe, Ni) and bimetallic (FeNi) were synthesized by varying experimental conditions. The phase, crystallinity and the magnetic properties of the materials synthesized were found to be dependent on experimental reaction parameters such as different solvents, electrodes, the spacing between electrodes, applied voltage, experiment time and high-temperature annealing. Fe and Gd-based nanoparticles were developed for high-performance magnetic resonance imaging (MRI) contrast enhancement. Biocompatible hybrid composite of Fe core – C shell nanoparticles evaluated as negative MRI contrast agents display remarkably high transverse relaxivity (r2) of 70 mM-1S-1 at 7T. In addition to 3d transition magnetic materials, magnetism of multilayer graphene nanosheets with only s and p electrons was investigated to understand and explain the intrinsic origin of ferromagnetism in carbon-based material. Apart from magnetic materials, noble metal Pd nanoparticles were developed using one-step process for hydrogen storage. The role of hydrogen on the dilation of Pd lattice was investigated using the experiment and density functional theory (DFT) studies. This method demonstrates that plasma discharge method using appropriate electrodes and solvents can be used to synthesize desired nanoparticles. This potential emphasizes the importance of adopting this methodology, which offers advantages that include a rapid reaction rate and ability to form very small nanoparticles with narrow size distribution.
Keywords
Plasma discharge, Core-shell nanoparticles, Magnetic nanoparticles, Hydrogen storage
Disciplines
Physical Sciences and Mathematics | Physics
License
This work is licensed under a Creative Commons Attribution-NonCommercial-Share Alike 4.0 International License.
Recommended Citation
Chaudhary, Rakesh Pratapbhai, "PLASMA-BASED SYNTHESIS OF NANOSTRUCTURED MATERIALS AND THEIR CHARACTERIZATION" (2017). Physics Dissertations. 155.
https://mavmatrix.uta.edu/physics_dissertations/155
Comments
Degree granted by The University of Texas at Arlington