| 项目编号: | 1510635
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| 项目名称: | UNS: Predicting the Interfacial Activity of Complex Grafted Nanoparticles |
| 作者: | Robert Riggleman
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| 承担单位: | University of Pennsylvania
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| 批准年: | 2014
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| 开始日期: | 2015-07-01
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| 结束日期: | 2018-06-30
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| 资助金额: | USD337159
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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: | nanoparticle
; effect
; polymer
; interfacial property
; interfacial tension
; surface
; polymer chain
; remarkable interfacial activity
; field theoretic simulation framework
; experiment
; emulsion
; interaction
; high school student
; multiple nanoparticle
; group
|
| 英文摘要: | #1510635
Riggleman, Robert A.
Numerous consumer products ranging from cosmetics, detergents, and fluids for oil recovery require the stabilization of two immiscible fluids (e.g., oils and water) as an emulsion, where one phase (typically the oil) is dispersed as stable droplets in the second phase (water). Recently, experiments have shown that adding nanometer-sized particles that have polymer chains grafted to their surface is an unusually effective and inexpensive method for stabilizing these emulsions, but the mechanism for stabilization remains poorly understood. The research goal of this proposal is to study the effect of the chemistry of the grafted polymer chains on the interfacial properties of grafted nanoparticles. We will study the conformations of the polymer brush on isolated nanoparticles, the interactions of multiple nanoparticles, including their effect on the interfacial tension and self-assembly at the interface, and we will study the effect of having charges on the grafted polymer chains. These calculations are enabled by recent simulation techniques developed in our group. Our educational goals include the training of graduate students in polymer science and engineering, and state-of-the-art simulation techniques. We will continue our group's effort at involving undergraduate and high school students in our research. Finally, we will impact the broader scientific community by developing and publishing simulation codes that perform our calculations.
In recent years, there has been a growing interest in the thermodynamics of nanoparticles functionalized with polymers for use in applications such as separations membranes and oil extraction fluids. By carefully tuning the interactions between the particle cores, the grafted chains, and any components that make up the host matrix of the grafted particles, one can easily control optical and mechanical properties simply by controlling the aggregation and dispersion state of the polymer. Very recently, experiments have shown that grafted nanoparticles exhibit a remarkable interfacial activity in oil and water emulsions, and they are highly effective at stabilizing the emulsions over long periods of time at surprisingly low concentrations. Furthermore, the effect of the grafting architecture has not been explored at all; recent advances in synthetic chemistry enables grafting diblock polymers, a mixture of homopolymers, or patchy (Janus) grafting on the surface of nanoparticles. This large parameter space available to experimentalists creates a need for molecular modeling that can guide experiments toward systems that show the most promise for various applications. The goal of this proposal is to use a field theoretic simulations framework recently developed by my group to examine the structure and interfacial properties of complex grafted nanoparticles. We will examine mixed brushes, diblock polymer brushes, and Janus brushes on the surface of nanoparticles as a function of the particle core size, grafting density, brush composition, and interactions with the matrix phases. Finally, we will examine how the picture changes when one of the polymers carries a charge, while incorporating the effects of ion solvation and dielectric mismatch between the two phases creating the interface. Overall, we expect our results to have a significant impact on the design of future experiments.
Our efforts will have a broad impact to society by providing fundamental insights into the design of fluids for oil extraction and a wide variety of consumer products. In addition to the doctoral students trained in polymer physics and state-of-the-art molecular modeling techniques, our work has a substantial education and outreach component involving undergraduate (and potentially high school student) research, course development, and outreach to the scientific community in general. Our lab has one undergraduate student currently working with us who has co-authored a paper, and in the summer of 2014 we had a local high school student visit our lab, performing molecular dynamics simulations of polymer melts. We are developing course modules both for specialized molecular modeling courses as well as broad first-year statistical mechanics courses that introduce and develop the field theoretic simulations framework. Finally, in addition to the standard conference meetings promoting our work, we are developing a code base that we can publish and freely release to the public. Our hope is to broaden the application and use of the field theoretic simulations framework, and we believe this can be most effectively achieved by lowering the barrier to entry. Making our codes widely available is a key part of that vision. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/94304
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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: | |
Robert Riggleman. UNS: Predicting the Interfacial Activity of Complex Grafted Nanoparticles. 2014-01-01.
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