Construction and characterization of hybrid nanoparticles via block copolymer blends and kinetic control of solution assembly
| Author(s) | Chen, Yingchao | |
| Date Accessioned | 2016-02-09T13:37:33Z | |
| Date Available | 2016-02-09T13:37:33Z | |
| Publication Date | 2015 | |
| Abstract | Amphiphilic block copolymers are able to self-assemble into well-defined nanostructures in aqueous solutions or aqueous/miscible organic solutions. These structures include traditional spheres, cylinders and vesicles, which mimic nanostructures formed by small molecule analogs like lipids and surfactants. The large molecular weight and complex macromolecular architectures provide several advantages over small molecule amphiphiles, including the large chemical versatility, control over the size and shape of the solution assemblies, unique slow chain exchange and exceptional increased versatility in possible nanostructures. These advantages have motivated the noteworthy study of constructing well-defined, controlled and, especially, multicompartment and multigeometry polymeric nanoobjects for potential multiple nanotechnology applications. To reach complexity and well-controlled nanostructures, the facile utility and fundamental understanding of the parameters that influence the effective construction of solution assemblies needs to be continued. Given these motivations, this dissertation demonstrated the design of block copolymers, manipulation of kinetic control parameters of solution assembly, and characterization of hybrid nanostructures with the aim of creating new, well-defined nanostructures. The first objective of this dissertation was to explore the effects of solvent processing rates in influencing multicompartment and multigeometry nanoparticle construction, structure evolution over long-time aging and nanoparticle formation mechanisms. The noticeable effects of water addition rates on the formation of various nanostructures were studied by cryogenic transmission electron microscopy, selective staining and small angle scattering. It was revealed that the water addition rate have significant influence over the final assemblies in block copolymer blends. New shapes of multicompartment and multigeometry nanoparticles have been constructed including hybrid vesicles, vesicle-cylinder connected nanoparticles, and disk-cylinder nanoparticles. It is discovered that smaller, kinetically-trapped, blended nanoparticles are observed with faster water addition rates, compared with larger, non-blended distinct nanoparticles with separate, unique geometries formed with slower water addition rate. The revealed rules were then applied in constructing new multicompartment hybrid nanoparticles with designed geometries, including the hybrid disks, hybrid cylinders and star-like nanoparticles. The second objective of this work was to explore a method for making hierarchical nanoparticle superstructures with designed functionality and subsequent multistep assembly and interparticle crosslinking. Advanced imaging of various nanostructures in different solution assembly systems was also generated. Together, the ideas of parameter control, kinetic study, and design of molecules and functionality presented in this dissertation will facilitate future work and nanotechnology development. | en_US |
| Advisor | Pochan, Darrin J. | |
| Degree | Ph.D. | |
| Department | University of Delaware, Department of Materials Science and Engineering | |
| Unique Identifier | 937697396 | |
| URL | http://udspace.udel.edu/handle/19716/17439 | |
| Publisher | University of Delaware | en_US |
| URI | http://search.proquest.com/docview/1727750821?accountid=10457 | |
| dc.subject.lcsh | Nanoparticles. | |
| dc.subject.lcsh | Nanostructures -- Design and construction. | |
| dc.subject.lcsh | Block copolymers. | |
| dc.subject.lcsh | Solution (Chemistry) | |
| dc.subject.lcsh | Water. | |
| dc.subject.lcsh | Transmission electron microscopy. | |
| dc.subject.lcsh | Self-assembly (Chemistry) | |
| Title | Construction and characterization of hybrid nanoparticles via block copolymer blends and kinetic control of solution assembly | en_US |
| Type | Thesis | en_US |