Keywords and Phrases
Aerogels; Drug Delivery; Flexible Aerogels; Polydicyclopentadienes; Polyurethane-acrylate; Polyurethane-norbornene
"Aerogels are 3-D light-weight nanoporous materials pursued for their low thermal conductivity, low dielectric constant and high acoustic attenuation. Those exceptional macroscopic properties of aerogels are dependent on the chemical nature of nanoparticles, complex hierarchical solid skeletal framework and porosity. Also, the free space can become host for functional guests such as pharmaceuticals. In chapter I, we investigated randomly mesoporous bio-compatible polymer-crosslinked dysprosia aerogels as drug delivery vehicles and demonstrated storage and release of drugs under physiological conditions. Comparative study with ordered and randomly mesoporous silica showed high drug uptake and slower release rate for random nanostructures (silica or dysprosia) relative to ordered silica. Drug release data from dysprosia aerogels showed that drug is stored successively in three hierarchical pore sites on the skeletal framework. In chapter II, we developed flexible polyurethane-acrylate aerogels from star monomer containing urethane linkage and terminal acrylate bonds by free-radical polymerization. Lower density samples were flexible, while higher density samples were mechanically strong. Those results were dependent on the particle size and interparticle connectivity of skeletal framework, pointing to a nanoscopic origin for their flexibility, rather than to a molecular one. Further, the acrylate bonds were converted to norbornene moieties and the gelation process was brought down to room temperature by using ring opening metathesis polymerization (ROMP). In chapter III, we developed polydicyclopentadiene (pDCPD) based aerogels using two different Grubbs catalysts (GC-I and GC-II) with different catalytic activity towards ROMP. The different behavior of pDCPD aerogels was traced to a different polymer configuration at molecular level."--Abstract, page v.
Winiarz, Jeffrey G.
Ph. D. in Chemistry
Missouri University of Science and Technology
Journal article titles appearing in thesis/dissertation
- Evaluation of dysprosia aerogels as drug delivery systems: A comparative study with random and ordered mesoporous silicas
- Flexible aerogels from hyperbranched polyurethanes. Probing the role of monomer rigidity by comparing poly(urethane-acrylates) versus poly(urethane-norbornenes)
- Polydicyclopentadiene aerogels using 1st versus 2nd generation Grubbs' catalysts: A reconciliation from a molecular and nanoscopic perspective
xviii, 286 pages
© 2014 Abhishek Bang, All rights reserved.
Dissertation - Open Access
Electronic OCLC #
Bang, Abhishek N., "Aerogels as diverse nanomaterials" (2014). Doctoral Dissertations. 2601.