Date of Last Revision

2023-05-03 05:26:44


Chemical Engineering - Cooperative Education

Degree Name

Bachelor of Science

Date of Expected Graduation

Spring 2020


The dynamics of polymer thin films have been demonstrated to be significantly altered from the bulk, but the origins of such differences are not well defined. In this work, we seek to understand the differences in the structural dynamics (or physical aging) of polystyrene (PS) through branching and other well defined architectures (comb and centipede). The aging dynamics of ultrathin films (< 30 nm) differ from relatively thick films (100-150nm) with linear PS thin films aging more rapidly than the relatively “bulk-like” thick films. Ellipsometric measurements are used to characterize the physical aging rate of the films. The change in film thickness and refractive index as the films are held below the glass transition temperature (Tg) provides a simple measure of the physical aging. In this study, four different architectures (linear, comb, 4 arm star, and centipede) will be investigated. For each PS architecture, the aging rate will be determined for film thickness ranging from 10nm to 100nm over aging temperatures from 65C to 95C. Preliminary investigation shows that the branching of the PS will decrease the aging rate.

Research Sponsor

Bryan D. Vogt

First Reader

Nicole Zacharia

Second Reader

Jie Zheng

REU FInal Report.doc (366 kB)
Supplementary report for Poster