GEORGIA INSTITUTE OF TECHNOLOGY

Under the provisions of the regulations for the degree

DOCTOR OF PHILOSOPHY

on Monday, April 22, 2019

12:00 PM

in MRDC 3515

will be held the

DISSERTATION PROPOSAL DEFENSE

for

Monica Marks

"Non-Leaching Antimicrobial Additive for Silicone Systems"

Committee Members:

Prof. Kyriaki Kalaitzidou, Advisor, ME/MSE

Prof. Will Gutekunst, Advisor, CHEM

Prof. Mary Lynn Realff, MSE

Prof. Blair Brettmann, MSE

Prof. Julie Champion, ChBE

Abstract:

All non-living material surfaces are colonized by microorganisms. In favorable conditions, these microorganisms proliferate and develop complex surface colonies called biofilms. Biofilms are an essential part of all ecosystems; however, for certain material applications, biofilms can be detrimental to device operation and human health. One such application is the use of silicone rubber for biomedical devices. Silicone rubbers are widely used in biomedical applications due to their elasticity, chemical and thermal resistance and biocompatibility; however, they suffer from biofouling. Commercial methods to make antimicrobial silicone include, silver compounds and nanoparticles and quaternary ammonium cations (QAC) as coatings or additives. Both silver and unbound small molecule QACs leach from the silicone surface. Leaching antimicrobial agents have uncontrolled activity and can bioaccumulate in the body and in the environment. This accumulation can pose many threats, including toxicity to non-target organisms and antimicrobial resistance

This proposal addresses the potential the use of a PDMS polymer, chain-end functionalized with QAC dendrimers, as a non-leaching antimicrobial additive in silicone systems. The QAC dendrimers introduce tunable charge density through degree of branching. I hypothesize that the QAC dendrimer chain-ends will surface segregate within the PDMS matrix, by means of an entropically driven process, rendering the surface antimicrobial through the use of an additive.