Measuring the unusually slow ionic diffusion in polyaniline via study of yolk-shell nanostructures
We demonstrate a unique capability in partially oxidizing the oligoaniline shell on gold nanoparticles to polyaniline. Because of the solubility difference, the unreacted inner shell section can be selectively dissolved by 2-propanol, giving yolk-shell nanostructures and, thus, making it possible fo...
| Main Authors: | , , , , , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2013
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| Online Access: | https://hdl.handle.net/10356/97642 http://hdl.handle.net/10220/11252 |
| _version_ | 1826115356823912448 |
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| author | Sun, Hang Shen, Xiaoshuang Yao, Lin Xing, Shuangxi Wang, Hong Feng, Yuhua Chen, Hongyu |
| author2 | School of Physical and Mathematical Sciences |
| author_facet | School of Physical and Mathematical Sciences Sun, Hang Shen, Xiaoshuang Yao, Lin Xing, Shuangxi Wang, Hong Feng, Yuhua Chen, Hongyu |
| author_sort | Sun, Hang |
| collection | NTU |
| description | We demonstrate a unique capability in partially oxidizing the oligoaniline shell on gold nanoparticles to polyaniline. Because of the solubility difference, the unreacted inner shell section can be selectively dissolved by 2-propanol, giving yolk-shell nanostructures and, thus, making it possible for assessing the oxidized section. The ionic diffusion through the polymer shell is found to be the rate-determining step in the overall process. Conservative estimates show that the diffusion coefficient of AuCl4– is at least 700 times slower than that of the typical rate values in traditional studies. It is most likely caused by the lack of micropores in the polymer structures. Such mircopores are hard to avoid in preparing polymer membranes by casting or drying of polymers dissolved in organic solvents. We can rule out the presence of irregular pores on the basis of the uniformly oxidized shell section. With the nanoscale shells, the system is sensitive enough to detect minute changes in the shell or small differences among the individual nanoparticles. Even with a small increase in porosity, for example, when the polyaniline shell is swollen using small amounts of DMF (3%, 5%, or 10% in aqueous solutions), the diffusion coefficient of AuCl4– increases to 4, 11, and 17 times, respectively. Thus, our study demonstrates a new methodology for studying the diffusion of ions in hydrophobic polymers. |
| first_indexed | 2024-10-01T03:53:48Z |
| format | Journal Article |
| id | ntu-10356/97642 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T03:53:48Z |
| publishDate | 2013 |
| record_format | dspace |
| spelling | ntu-10356/976422020-03-07T12:31:27Z Measuring the unusually slow ionic diffusion in polyaniline via study of yolk-shell nanostructures Sun, Hang Shen, Xiaoshuang Yao, Lin Xing, Shuangxi Wang, Hong Feng, Yuhua Chen, Hongyu School of Physical and Mathematical Sciences We demonstrate a unique capability in partially oxidizing the oligoaniline shell on gold nanoparticles to polyaniline. Because of the solubility difference, the unreacted inner shell section can be selectively dissolved by 2-propanol, giving yolk-shell nanostructures and, thus, making it possible for assessing the oxidized section. The ionic diffusion through the polymer shell is found to be the rate-determining step in the overall process. Conservative estimates show that the diffusion coefficient of AuCl4– is at least 700 times slower than that of the typical rate values in traditional studies. It is most likely caused by the lack of micropores in the polymer structures. Such mircopores are hard to avoid in preparing polymer membranes by casting or drying of polymers dissolved in organic solvents. We can rule out the presence of irregular pores on the basis of the uniformly oxidized shell section. With the nanoscale shells, the system is sensitive enough to detect minute changes in the shell or small differences among the individual nanoparticles. Even with a small increase in porosity, for example, when the polyaniline shell is swollen using small amounts of DMF (3%, 5%, or 10% in aqueous solutions), the diffusion coefficient of AuCl4– increases to 4, 11, and 17 times, respectively. Thus, our study demonstrates a new methodology for studying the diffusion of ions in hydrophobic polymers. 2013-07-12T01:41:15Z 2019-12-06T19:44:51Z 2013-07-12T01:41:15Z 2019-12-06T19:44:51Z 2012 2012 Journal Article Sun, H., Shen, X., Yao, L., Xing, S., Wang, H., Feng, Y., et al. (2012). Measuring the Unusually Slow Ionic Diffusion in Polyaniline via Study of Yolk-Shell Nanostructures. Journal of the American Chemical Society, 134(27), 11243-11250. https://hdl.handle.net/10356/97642 http://hdl.handle.net/10220/11252 10.1021/ja3036674 en Journal of the American chemical society © 2012 American Chemical Society. |
| spellingShingle | Sun, Hang Shen, Xiaoshuang Yao, Lin Xing, Shuangxi Wang, Hong Feng, Yuhua Chen, Hongyu Measuring the unusually slow ionic diffusion in polyaniline via study of yolk-shell nanostructures |
| title | Measuring the unusually slow ionic diffusion in polyaniline via study of yolk-shell nanostructures |
| title_full | Measuring the unusually slow ionic diffusion in polyaniline via study of yolk-shell nanostructures |
| title_fullStr | Measuring the unusually slow ionic diffusion in polyaniline via study of yolk-shell nanostructures |
| title_full_unstemmed | Measuring the unusually slow ionic diffusion in polyaniline via study of yolk-shell nanostructures |
| title_short | Measuring the unusually slow ionic diffusion in polyaniline via study of yolk-shell nanostructures |
| title_sort | measuring the unusually slow ionic diffusion in polyaniline via study of yolk shell nanostructures |
| url | https://hdl.handle.net/10356/97642 http://hdl.handle.net/10220/11252 |
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