Collaborative Research: The Role of Sulfonated Polymer Membrane Morphology in Microscale Transport of Organic Molecules

合作研究：磺化聚合物膜形态在有机分子微尺度传输中的作用

• 批准号: 1836551
• 负责人: Sergey Vasenkov
• 金额: $ 12万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1836551&HistoricalAwards=false
• 关键词: Collaborative; Research; Role; Sulfonated; Polymer

Advanced chemical sensors enable technologies such as point-of-care medical testing and personal protective equipment against chemical warfare agents. Increasing sophistication of the chemical sensors derives from advances in the materials used as the sensor or in studying existing materials with unusual properties. One such material is the commercial polymer, Nafion, which is used in electrolysis, mineral extraction, specialty chemical synthesis, electrochemical sensors, and fuel cells. The widespread use of Nafion is due to its unique chemical structure, which is comprised of a long hydrophobic (water repellent) backbone of fluorine and carbon atoms and hydrophilic (water loving) branches. These dual functionalities give rise to high chemical stability, high reactivity, and flexibility in the presence of water. The dual functionality also leads to unique transport of molecules through the material, particularly when fabricated into a thin membrane. Transport of small molecules within the Nafion membrane is well described by existing theories. However, transport of larger organic compounds, such as those found in chemical warfare agents, cannot be explained within existing theoretical frameworks, particularly when the water-induced flexibility of Nafion is considered. This project will use advanced experimental techniques to deduce transport of large organic molecules that are representative of chemical warfare agents through the dynamic Nafion membrane. This project will develop a direct mechanistic understanding of water-enabled transport of organic molecules through Nafion membranes. Preliminary data suggests large organic molecules are effectively immobilized in a tertiary interphase region between hydrophobic and hydrophilic domains in dry Nafion. The source of this interphase is hypothesized to be the fluoroether linkage between the backbone and the perfluorosulfonic acid side chains. However, phenols and other weak organic acids remain immobilized under both dry and wet conditions. This project will probe the interphase, and the role of bulk sulfonated polystyrene copolymers on transport of large organic molecules in mixed solvent systems. An interdisciplinary team will employ small angle neutron scattering, X-ray scattering, and nuclear magnetic resonance at high magnetic fields. If successful, the proposed research will resolve the relationship between the structural and dynamic properties of the distinctly different domains in perfluorosulfonic acid and sulfonated polystyrene membranes. Specifically, the investigation will determine impact of domain morphology on the transport, immobilization, and reactivity of organic molecules. The project will support graduate education, create new teaching modules, and community outreach activities that demonstrate opportunities at the intersection of transport, catalysis and structure optimization of polymeric membranes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

高级化学传感器启用技术，例如保健医疗测试和针对化学战剂的个人防护设备。化学传感器的复杂性越来越复杂，这是从用作传感器或研究具有异常特性的现有材料的材料的进步。一种这样的材料是商业聚合物Nafion，用于电解，矿物质提取，特种化学合成，电化学传感器和燃料电池。 Nafion的广泛使用是由于其独特的化学结构所致，该结构由氟原子和碳原子以及亲水性（水爱）分支的长疏水（水驱虫）主链组成。这些双重功能在水存在下产生了高化学稳定性，高反应性和柔韧性。双重功能还导致分子通过材料的独特运输，尤其是在制造成薄膜时。现有理论很好地描述了在Nafion膜内的小分子的运输。但是，在现有的理论框架内无法解释较大的有机化合物的运输，例如化学战剂中发现的化合物，尤其是当考虑到水引起的Nafion柔韧性时。该项目将使用先进的实验技术来推断大型有机分子的运输，这些有机分子通过动态Nafion膜代表化学战剂。该项目将对有机分子通过Nafion膜的水传输有直接的机械理解。初步数据表明，大的有机分子有效地固定在干nafion中疏水和亲水域之间的第三纪之间区域。该相间的来源被认为是主链和全氟磺酸侧链之间的荧光连接。然而，在干燥和潮湿的条件下，苯酚和其他弱有机酸仍然固定。该项目将探测相间，以及大量磺化聚苯乙烯共聚物在混合溶剂系统中大型有机分子传输中的作用。跨学科的团队将在高磁场上采用小角度中子散射，X射线散射和核磁共振。如果成功的话，拟议的研究将解决全氟磺酸与磺化聚苯乙烯膜中明显不同域的结构和动态特性之间的关系。具体而言，研究将确定域形态对有机分子的转运，固定和反应性的影响。该项目将支持研究生教育，创建新的教学模块以及社区外展活动，这些活动在运输，催化和结构优化的聚合物膜的交汇处。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛影响的审查审查标准来通过评估来通过评估来获得支持的。

项目成果

Self‐Diffusion of a Chemical Warfare Agent Simulant and Water in Nafion by Pulsed Field Gradient NMR

通过脉冲场梯度 NMR 分析化学战剂模拟物和水在 Nafion 中的自扩散

• DOI: 10.1002/cite.202300010
• 发表时间: 2023
• 期刊: Chemie Ingenieur Technik
• 影响因子: 1.9
• 作者: Trusty, Blake;Fang, Junchuan;Angelopoulos, Anastasios;Vasenkov, Sergey
• 通讯作者: Vasenkov, Sergey

Transition between Different Diffusion Regimes and Its Relationship with Structural Properties in Nafion by High Field Diffusion NMR in Combination with Small-Angle X-ray and Neutron Scattering

• DOI: 10.1021/acs.jpcb.0c07249
• 发表时间: 2020-10-08
• 期刊: JOURNAL OF PHYSICAL CHEMISTRY B
• 影响因子: 3.3
• 作者: Berens, Samuel J.;Yahya, Ahmad;Vasenkov, Sergey
• 通讯作者: Vasenkov, Sergey