Stimuli-responsive polymer nanotube arrays
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2011.
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| Format: | Thesis |
| Language: | eng |
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Massachusetts Institute of Technology
2011
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| Online Access: | http://hdl.handle.net/1721.1/65659 |
| _version_ | 1826195090752667648 |
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| author | Chia, Khek-Khiang |
| author2 | Robert E. Cohen and Michael F. Rubner. |
| author_facet | Robert E. Cohen and Michael F. Rubner. Chia, Khek-Khiang |
| author_sort | Chia, Khek-Khiang |
| collection | MIT |
| description | Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2011. |
| first_indexed | 2024-09-23T10:06:52Z |
| format | Thesis |
| id | mit-1721.1/65659 |
| institution | Massachusetts Institute of Technology |
| language | eng |
| last_indexed | 2024-09-23T10:06:52Z |
| publishDate | 2011 |
| publisher | Massachusetts Institute of Technology |
| record_format | dspace |
| spelling | mit-1721.1/656592019-04-12T20:57:16Z Stimuli-responsive polymer nanotube arrays Chia, Khek-Khiang Robert E. Cohen and Michael F. Rubner. Massachusetts Institute of Technology. Dept. of Chemical Engineering. Massachusetts Institute of Technology. Dept. of Chemical Engineering. Chemical Engineering. Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2011. This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. Cataloged from student submitted PDF version of thesis. Includes bibliographical references. Nanotube arrays, composed of materials such as carbon, titania, and zinc oxide, have shown potential as conductors, energy conversion devices, actuators, and adhesives. Such nanoscale constructs are particularly novel for their high area-to-volume and length-to-diameter aspect ratios that lead to physical and chemical properties more interesting than their bulk counterparts. However, the stimuli-responsiveness of nanotube arrays has seldom been explored, mostly due to the inertness of the materials typically utilized to create them. Here I introduce a new concept of designing and synthesizing surface-bound stimuli-responsive polymer nanotubes with dynamic mechanical properties. Polyelectrolyte multilayers (PEMs) composed of poly(allylamine hydrochloride) and poly(acrylic acid) were chosen as the nanotube building blocks for their ability to undergo pH-triggered swelling-deswelling transitions. The swelling behavior was first demonstrated in the in situ synthesis of gold nanoparticles in the PEM; upon suitable post-assembly treatment, the PEM undergoes substantial molecular rearrangements that generate free amine groups available for gold salt binding. Characterization of the size and distribution of the gold nanoparticles as a function of assembly condition and post-assembly treatment, and in situ ellipsometry thickness measurement of the PEM film during the swelling transition provided further insights into the swelling behavior. These studies ultimately led to the design and synthesis of reversibly swellable PEM nanotube arrays via layer-by-layer assembly on porous templates. The template-based approach allows straightforward control over the length, diameter, orientation and lateral arrangement of the resultant tube array, which can be challenging with other synthesis methods. Activation of the swelling transition resulted in dramatic changes in the length and diameter of the tube arrays as characterized in situ via confocal laser scanning microscopy, and in the effective modulus of the nanotube arrays as measured by AFM-based nanoindentation. Parallel to experimental work, finite element analysis of simulated indentation on the nanotube arrays showed deformation mechanisms and a discontinuous stress-and-strain field different than that of a flat film. Template-based nanotube synthesis is further applied to the assembly of nanotubes with thermal- and magnetic-responsiveness, as well as incorporating cell-receptor-interacting biopolymers. by Khek-Khiang Chia. Ph.D. 2011-09-13T14:32:59Z 2011-09-13T14:32:59Z 2011 2011 Thesis http://hdl.handle.net/1721.1/65659 749110895 eng M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582 149 p. application/pdf Massachusetts Institute of Technology |
| spellingShingle | Chemical Engineering. Chia, Khek-Khiang Stimuli-responsive polymer nanotube arrays |
| title | Stimuli-responsive polymer nanotube arrays |
| title_full | Stimuli-responsive polymer nanotube arrays |
| title_fullStr | Stimuli-responsive polymer nanotube arrays |
| title_full_unstemmed | Stimuli-responsive polymer nanotube arrays |
| title_short | Stimuli-responsive polymer nanotube arrays |
| title_sort | stimuli responsive polymer nanotube arrays |
| topic | Chemical Engineering. |
| url | http://hdl.handle.net/1721.1/65659 |
| work_keys_str_mv | AT chiakhekkhiang stimuliresponsivepolymernanotubearrays |