Design of polymeric substrates for controlled molecular crystallization
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2012.
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| Format: | Thesis |
| Language: | eng |
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Massachusetts Institute of Technology
2012
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| Online Access: | http://hdl.handle.net/1721.1/70408 |
| _version_ | 1826192447692079104 |
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| author | Diao, Ying, Ph.D. Massachusetts Institute of Technology |
| author2 | Bernhardt L. Trout and T. Alan Hatton. |
| author_facet | Bernhardt L. Trout and T. Alan Hatton. Diao, Ying, Ph.D. Massachusetts Institute of Technology |
| author_sort | Diao, Ying, Ph.D. Massachusetts Institute of Technology |
| collection | MIT |
| description | Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2012. |
| first_indexed | 2024-09-23T09:13:38Z |
| format | Thesis |
| id | mit-1721.1/70408 |
| institution | Massachusetts Institute of Technology |
| language | eng |
| last_indexed | 2024-09-23T09:13:38Z |
| publishDate | 2012 |
| publisher | Massachusetts Institute of Technology |
| record_format | dspace |
| spelling | mit-1721.1/704082019-04-10T17:47:46Z Design of polymeric substrates for controlled molecular crystallization Diao, Ying, Ph.D. Massachusetts Institute of Technology Bernhardt L. Trout and T. Alan Hatton. 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, 2012. Cataloged from PDF version of thesis. Includes bibliographical references (p. 171-175). It is essential to control crystallization in many areas of science and technology, such as the production of pharmaceuticals, pigments, concrete, semiconductors, as well as the formation of biominerals. In most practical circumstances, crystallization starts with heterogeneous nucleation at a foreign surface. Despite its widespread occurrence, mechanistic understanding of the role of a surface in heterogeneous nucleation is limited, especially in a solution environment. My thesis aims at elucidating the roles of surface chemistry and nanostructure on nucleation to enable rational design of surfaces for controlling crystallization from solution. To this end, I systematically investigated the role of surface chemistry, morphology, in particular porous structures of various polymeric materials on heterogeneous nucleation using small organic molecules as model compounds. I have demonstrated quantitatively the significance of surface chemistry to nucleation kinetics using a variety of polymer surfaces. By tuning the surface composition of the polymers, aspirin nucleation was promoted by up to an order of magnitude compared to the bulk. Further mechanistic investigations revealed that, macroscopically, it is through interfacial free energies that the surfaces influence the surface nucleation activity. Equipped with nucleation induction time statistics as a powerful tool, I found that nanoscopic pores of 50-100 nm accelerated nucleation by up to two orders of magnitude compared with surfaces without pores. Moreover, I demonstrated for the first time that the shape of surface nanopores is essential in determining the nucleation behavior, using lithographic methods for nanopatterning the polymer films. A molecular mechanism was further proposed based on additional mechanistic investigations. Furthermore, the nanoconfinement effect on nucleation was studied using polymeric microgels with tunable nanostructures and chemistry, whose mesh sizes range from 0.7-2 nm. We presented the first experimental evidence for the existence of an optimum confinement size at which the rate of nucleation was dramatically enhanced by up to four orders of magnitude. The degree of nucleation enhancement depends on the extent of polymer-solute interactions, whose role was elucidated from the perspective of adsorptive partitioning and nucleation-templating effect. In addition, the microgel nanostructure was also shown to play an important role in determining the crystal polymorphism of pharmaceutical compounds. by Ying Diao. Ph.D. 2012-04-26T18:50:50Z 2012-04-26T18:50:50Z 2012 2012 Thesis http://hdl.handle.net/1721.1/70408 784152235 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 175 p. application/pdf Massachusetts Institute of Technology |
| spellingShingle | Chemical Engineering. Diao, Ying, Ph.D. Massachusetts Institute of Technology Design of polymeric substrates for controlled molecular crystallization |
| title | Design of polymeric substrates for controlled molecular crystallization |
| title_full | Design of polymeric substrates for controlled molecular crystallization |
| title_fullStr | Design of polymeric substrates for controlled molecular crystallization |
| title_full_unstemmed | Design of polymeric substrates for controlled molecular crystallization |
| title_short | Design of polymeric substrates for controlled molecular crystallization |
| title_sort | design of polymeric substrates for controlled molecular crystallization |
| topic | Chemical Engineering. |
| url | http://hdl.handle.net/1721.1/70408 |
| work_keys_str_mv | AT diaoyingphdmassachusettsinstituteoftechnology designofpolymericsubstratesforcontrolledmolecularcrystallization |