Using ultrafast infrared spectroscopy to study free volume in polymer materials
Abstract/Contents
- Abstract
- The study of the microscopic structure of polymer membranes has been the subject of research efforts for many decades. This research field has seen the development of both theoretical and experimental techniques that seek to understand the connection between molecular-level structure and macroscopic material properties. In parallel, ultrafast infrared spectroscopic techniques were developed to study the structure and dynamics of various molecular systems. Because infrared spectroscopy directly probes molecular vibrations, it is especially suited to provide structural information, and the development of high power and ever shorter laser pulses allowed the extraction of molecular dynamical information with remarkable time resolution. However, despite the many successes of time-resolved infrared spectroscopy with various chemical systems, with some exceptions, this technique has remained mostly absent from the field of polymer research. This work presents research performed to bridge this gap and provide a fundamentally new spectroscopic technique capable of extracting structural, dynamical, and electrostatic information of polymer membranes with great sensitivity, and in a non-destructive and minimally perturbative manner. This work focuses on different aspects of polymer research. It begins with a study of long-lived first vibrational excited sates and their importance as probes for the extraction of polymer structural information. Next, a study on new notions regarding the use of the first-order Stark effect to study environment specific dynamics -- which is crucial to the study of structurally heterogeneous polymer membranes - is presented. Then, a new technique called Restricted Orientation Anisotropy Method (ROAM) is developed, which uses a polarization-selective pump-probe spectroscopy experiment to extract free volume element sizes, size distributions, dynamic time scales, and intrinsic electric fields from polymer membranes. ROAM is then used to study the connection between free volume and polymer dielectric breakdown. Finally, ROAM is used to successfully probe physical aging in a polymer membrane. Together these studies provide an experimental framework for a fundamentally new way of studying polymers, and a direct connection between their macroscopic properties and microscopic structure.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2023; ©2023 |
| Publication date | 2023; 2023 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Fica Contreras, Sebastian Matias |
|---|---|
| Degree supervisor | Fayer, Michael D |
| Thesis advisor | Fayer, Michael D |
| Thesis advisor | Cegelski, Lynette |
| Thesis advisor | Zare, Richard N |
| Degree committee member | Cegelski, Lynette |
| Degree committee member | Zare, Richard N |
| Associated with | Stanford University, School of Humanities and Sciences |
| Associated with | Stanford University, Department of Chemistry |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Sebastian Matias Fica Contreras. |
|---|---|
| Note | Submitted to the Department of Chemistry. |
| Thesis | Thesis Ph.D. Stanford University 2023. |
| Location | https://purl.stanford.edu/wx112xy6516 |
Access conditions
- Copyright
- © 2023 by Sebastian Matias Fica Contreras
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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