Nano-mechanical testing of colloidal nanostructures and self-assembled films
Abstract/Contents
- Abstract
- Understanding the mechanical behavior of nanostructures is crucial for their use in lightweight, strong, and multifunctional materials. Here, three different colloidal nanocrystals are tested in compression to gain insight into the role of microstructure, structural porosity, surface passivation and roughness, and strain rate on plastic deformation. Single crystal Ag and Cu nanocubes are compressed using in situ scanning electron microscopy to study the effect of surface passivation by the colloidal surfactant ligands on strength. Hollow, single crystal Au-Ag alloy nanoboxes with sub-20 nm wall thickness are found to strain harden. This is related to stacking fault accumulation and interaction which is not observed in solid single crystal nanostructures. In contrast, hollow amorphous cobalt sulfide nanoboxes do not show strain hardening. In addition, deformation and fracture is found to be strain rate dependent. These nanoboxes are self-assembled into lightweight films with pores inside of each nanobox, as well as between neighboring nanoboxes. These films are found to be strain rate independent and similar to granular materials. Finally, I present a workflow for determining the mechanical properties of thin films or other small-scale structures that combines nano-mechanical testing and computational simulations. This approach is validated for the finite element modelling of viscoelastic optically clear adhesive thin films using nanoindentation and rheology experimental data.
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 | 2021; ©2021 |
| Publication date | 2021; 2021 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Patil, Radhika Pramod |
|---|---|
| Degree supervisor | Gu, Wendy |
| Thesis advisor | Gu, Wendy |
| Thesis advisor | Cai, Wei, 1977- |
| Thesis advisor | Zheng, Xiaolin, 1978- |
| Degree committee member | Cai, Wei, 1977- |
| Degree committee member | Zheng, Xiaolin, 1978- |
| Associated with | Stanford University, Department of Mechanical Engineering |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Radhika Patil. |
|---|---|
| Note | Submitted to the Department of Mechanical Engineering. |
| Thesis | Thesis Ph.D. Stanford University 2021. |
| Location | https://purl.stanford.edu/tt864zs5485 |
Access conditions
- Copyright
- © 2021 by Radhika Pramod Patil
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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