Thesis Defense: Sarah Av-Ron

Title

Design, Development, and Study of a New High-Throughput Biodegradation Test for Polymers

Abstract

The rise of plastic pollution requires an urgent response. The substitution of long-lasting commodity plastics with biodegradable alternatives has been a thoroughly researched solution. Unfortunately, current biodegradation standards are not allowing for fast biodegradation measurements on materials, and present other disadvantages such as requiring a large amount of material, lack of directions in sample preparation leading to limited comparability between different biodegradation results, or expensive experimental setups both financially and time wise. This thesis focuses on the design and improvement of an affordable biodegradation test based on the clear-zone assay. First, the test is proven to be high-throughput and used for generating the biodegradability information of over 600 polymer chemistries. This large dataset highlights some relationships between polymer chemistry and biodegradability. Secondly, an improved design of a clear-zone monitoring robot leads to higher accuracy of the extracted data. In combination with a new sample preparation process using polymer nanoprecipitation, the system enables the determination of biodegradation rates. Finally, a kinetic model capable of reproducing clear-zone assay results is developed.

Thesis Advisor

Bradley D. Olsen: Alexander and I. Michael Kasser (1960) Professor of Chemical Engineering, Chemical Engineering Department Executive Officer, MIT