Font Size: a A A

Polyelectrolytes in the synthesis of bio-inspired composite materials

Posted on:2008-12-18Degree:Ph.DType:Dissertation
University:University of California, Santa BarbaraCandidate:McKenna, Brandon JFull Text:PDF
GTID:1441390005962179Subject:Chemistry
Abstract/Summary:
This original research dissertation contains studies on complex coacervation, methods of modifying coacervates to create new materials as particularly applied to targeted drug delivery, and the use of coacervating polyanions for the assembly of intricate structures of calcium carbonate.;Complex coacervation is a liquid-liquid phase separation that typically produces microspherical droplets from the combination of a variety of oppositely charged ions, including polymers and nanoparticles. The chemical space of coacervating components was found dependent on the number of charged groups and pH. Coacervates were shown to present chemically active surfaces that could be solidified by various methods, some of which also induced hollow interiors. The resulting assemblies were considered for targeted drug delivery by using superparamagnetic magnetite nanoparticles as assembling components. Control over microsphere sizes was obtained from variation of several parameters, and porosities were examined as a function of cross-linking extent to determine encapsulation capabilities.;Coacervates were further found to direct mineral growth, first in the form of shells, and then in the form of complicated structures that require substrate interaction via a solution-amorphous-crystalline mechanism. A ternary phase diagram approach revealed a great diversity of morphologies that could be modulated by the action of coacervating polyanions. Detailed analysis of one particular stacked lamellar structure suggested an assembly mechanism that may have relevance for biomineralization of nacre.
Keywords/Search Tags:Complex coacervation, Targeted drug delivery
Related items