Elina Ghimire

Date of Award


Degree Type

Honors College Thesis


Polymers and High Performance Materials

First Advisor

Yoan C. Simon, Ph.D

Advisor Department

Polymers and High Performance Materials


Polymersomes, also known as polymer vesicles, are hollow capsules fabricated through the solution assembly of amphiphilic block copolymers. Polymer vesicles have garnered a great deal of interest in materials science because of their potential application in areas such as drug delivery, diagnostics and imaging, gene therapy, and as nanoreactors. The goal of this project is to understand the factors that affect the arrangement of triblocks in vesicle membrane via the study of the co-assembly behavior of linear amphiphilic triblocks with different hydrophilic blocks. We investigated the self- and co-assembly behavior of amphiphilic triblock copolymers with neutral hydrophilic blocks. Moreover, we compared the results obtained from the assembly of neutral triblocks to the self-assembly of zwitterionic and anionic triblock copolymers. First, a central hydrophobic poly(styrene-stat-coumarin methacrylate) (P(S-stat-CMA) block was synthesized by reversible addition-fragmentation chain-transfer (RAFT) copolymerization of the corresponding monomers using a difunctional chain transfer agent. The two neutral hydrophilic blocks N,N-dimethylacrylamide and poly(ethylene glycol) were added by the chain-extension and thio-Michael addition respectively. The zwitterionic [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide and the anionic sodium 4-styrene-sulfonate were also obtained via chain extension RAFT polymerization. The variations in sizes, orientation, and distribution patterns of the morphological structures characterized via light scattering and transmission electron microscopy are discussed.