| 项目编号: | 1438486
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| 项目名称: | Control of Photopolymerization Kinetics and Thermodynamics in Self-assembled Surfactant Systems to Direct Polymer Nanostructure |
| 作者: | Allan Guymon
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| 承担单位: | University of Iowa
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| 批准年: | 2013
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| 开始日期: | 2014-08-01
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| 结束日期: | 2018-07-31
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| 资助金额: | USD344932
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| 资助来源: | US-NSF
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| 项目类别: | Standard Grant
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| 国家: | US
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| 语种: | 英语
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| 特色学科分类: | Engineering - Chemical, Bioengineering, Environmental, and Transport Systems
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| 英文关键词: | polymer
; polymerization
; thermodynamics
; surfactant
; photopolymerization kinetics
; polymer structure evolution
; polymer network
; unfavorable polymer nanostructure
; ultimate polymer nanostructure
; nanostructured organic polymeric material
; direct polymer nanostructureproposal
; thiol-ene step growth photopolymerization mechanism
; polymerization kinetics
; polymerization rate
; surfactant/monomer chemistry
; self-assembled surfactant systems
; nanotechnology
; pi
; polymer structure
; organic polymer structure
; radical photopolymerization
; controlled nano-scale geometry
; polymer nanostructure
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| 英文摘要: | Title: Control of Photopolymerization Kinetics and Thermodynamics in Self-assembled Surfactant Systems to Direct Polymer Nanostructure
Proposal #1438486
PI: C. Allan Guymon
Institution: University of Iowa
Recent research has shown that nanotechnology, or the ability to control material structures at very small size scales, can provide unique and useful properties not accessible in traditional materials. Controlling organic polymer structure in materials similar to plastics and contact lenses at the nanometer scale has shown great promise in improving performance. There have been recent advances in developing nanoscale structure in polymer networks using surfactant, or soap, have involved self-assemblies, which are of particular interest. These surfactant (soap) molecules form lyotropic liquid crystals (LLC) in the presence of water that organize into ordered nanometer scale features which can be used to direct, or template, polymer structures. Materials made up of polymers templated by LLC phases have shown great potential in their response to temperature. They can be used as membranes and scaffolds to regenerate biological tissue. Controlling the structure during the polymerization is still difficult with structures typically being much different than the original template, and thus less useful. For this project the PI will use the speed of polymerization in systems with optimized stability to direct polymer structure evolution within LLC templates.
The overall goal is to control photopolymerization kinetics and thermodynamics before and during polymerization, and surfactant/monomer chemistry to understand and direct the structural evolution of polymers formed using LLC media. The PI will modulate surfactant and monomer chemical structure and reactivity to reinforce thermodynamic stability of the LLC-self-assembly to improve interactions between the growing polymer network and the template. These systems will be modeled using computational methods to evaluate the thermodynamic stability of the templating mixtures. It is believed that the use of radical photopolymerization will play a pivotal role in successful completion of this work. Photopolymerization provides the ability to polymerize in fractions of a second at a wide range of temperatures, thereby allowing kinetic trapping of otherwise thermodynamically unfavorable polymer nanostructures. Polymer nanostructures formed from both traditional chain and thiol-ene step growth photopolymerization mechanisms will be investigated. Critical for project success is the connection between the polymerization kinetics and polymer structure evolution. Polymerization rate, conversion, and phase separation will be monitored in real time using photo-differential scanning calorimetry and through infra-red and Raman spectroscopy experiments. Thermodynamics and kinetics will be correlated to nanostructure before, during, and after polymerization using numerous characterization techniques (small angle X-ray scattering, electron microscopy, solid state and solution NMR). The PI believes that this research will outline the kinetic and thermodynamic factors necessary to direct and control the ultimate polymer nanostructure.
This project will provide a relatively simple approach to controllably produce nanostructured organic polymeric materials. Polymers with controlled nano-scale geometries will exhibit unique transport properties and size selectivity, which are critical for advances in applications such as water purification, stimuli response, tissue scaffolds, and hydrogels. A prevailing theme for this research will be student education. Extensive involvement of undergraduate and graduate researchers in a discovery learning environment will be emphasized. Minority undergraduate and graduate researchers will be recruited as part of the NSF REU Program in Nanoscience and Nanotechnology. Additionally, the importance of polymers, nanotechnology, and chemical engineering will be brought to high school students as part of two modules presented yearly to chemistry classes at both local and rural high schools. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/96187
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| Appears in Collections: | 影响、适应和脆弱性
气候减缓与适应
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| Recommended Citation: | |
Allan Guymon. Control of Photopolymerization Kinetics and Thermodynamics in Self-assembled Surfactant Systems to Direct Polymer Nanostructure. 2013-01-01.
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