UNS: Interfacial Properties of Nanoconfined Ionic Liquid

UNS：纳米离子液体的界面性质

• 批准号: 2015653
• 负责人: Younjin Min
• 金额: $ 16.72万
• 依托单位: University of California-Riverside
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2021-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2015653&HistoricalAwards=false
• 关键词: UNS; Interfacial; Properties; Nanoconfined; Ionic

#1511626Min, YounjinIonic liquids (ILs) are a relatively new class of liquids that consist only of cations and anions. Some of the useful properties of typical ILs are their negligibly low vapor pressure, fire resistance, excellent chemical and thermal stability, wide liquid temperature ranges, and wide electrochemical windows. Given these excellent properties, ILs have been used or considered for use in organic synthesis, catalysis, chemical separation, and fuel and solar cells, and their applications continue to expand. Despite a plethora of emerging processes involving ILs, however, an understanding of the interfacial properties of ILs under confinement, such as rheological properties and glass transition temperatures, remain very limited compared with that of other confined material classes, such as polymers, electrolyte solutions, and liquid crystals. The objective of the proposed work is twofold: (i) to obtain relationships describing how the structure, viscosity, and glass transition temperature of ILs depend on degree of confinement (separation) and (ii) to obtain a fundamental understanding of how the molecular parameters of confined ILs, such as the relative sizes and shapes of cations and anions and the surface properties of confining surfaces, such as surface potential and degree of hydrophobicity, affect the abovementioned properties under nanoconfinement. Our main hypothesis is that when the dimension of confinement becomes comparable to the Debye screening length of ILs, the confined glass transition temperature deviates from the bulk glass transition temperature. This hypothesis will primarily be tested with the surface forces apparatus technique, which is a unique technique that can link molecular studies to meso-scale studies and also to bulk-scale studies. This work will be first of its kind to directly measure the viscosity and glass transition temperature of ILs under dynamically controlled nanoconfined environments. From a fundamental science perspective, the proposed work represents an important step in understanding the structure/property relationships of ILs under confinement. Such an understanding may ultimately lead to new fundamental insights into a systematic method to select an ion pair(s) for the rational design of ILs operating under nanoconfined environments and with the desired physical properties. This project will first provide pivotal guidelines to select desirable types of ILs on demand on the basis of their important interfacial properties under nanoconfinement. Such knowledge will be useful to optimize and design applications involving confined ILs, such as batteries, solar cells, and lubricants. The educational plan consists of three main components that will focus on the research supervision of students, teaching, mentoring, and outreach to interface with the research components of the project. These components include the (i) development of a new graduate course on the interfacial phenomena of soft matter to be taught by the PI, (ii) mentoring of underrepresented undergraduate students in research, and (iii) dissemination of the project outcomes to the general public in the Akron area, where the minority constitutes 25% of the total population, by reliance on the connections established with local high school teachers through an educational electronic device development grant funded by NSF.

#1511626Min，Younjin 离子液体 (IL) 是一类相对较新的液体，仅由阳离子和阴离子组成。典型离子液体的一些有用特性包括可忽略不计的低蒸气压、耐火性、优异的化学和热稳定性、宽的液体温度范围和宽的电化学窗口。鉴于这些优异的性能，离子液体已被用于或考虑用于有机合成、催化、化学分离以及燃料和太阳能电池，并且其应用不断扩大。尽管有大量涉及离子液体的新兴工艺，然而，与其他受限材料类别（例如聚合物、电解质溶液、和液晶。拟议工作的目标有两个：（i）获得描述离子液体的结构、粘度和玻璃化转变温度如何依赖于限制（分离）程度的关系；（ii）获得对分子参数如何变化的基本了解限制离子液体的性质，例如阳离子和阴离子的相对大小和形状以及限制表面的表面性质，例如表面电势和疏水性程度，影响纳米限制下的上述性质。我们的主要假设是，当限制尺寸与离子液体的德拜屏蔽长度相当时，限制玻璃化转变温度会偏离整体玻璃化转变温度。该假设将主要通过表面力装置技术进行测试，这是一种独特的技术，可以将分子研究与介观尺度研究以及整体尺度研究联系起来。这项工作将是首次在动态控制的纳米受限环境下直接测量离子液体的粘度和玻璃化转变温度。从基础科学的角度来看，拟议的工作代表了理解限制下离子液体的结构/性质关系的重要一步。这种理解最终可能会带来对选择离子对的系统方法的新的基本见解，以合理设计在纳米受限环境下运行并具有所需物理性质的离子液体。该项目将首先提供关键指南，以根据纳米限制下离子液体的重要界面特性按需选择所需类型的离子液体。这些知识将有助于优化和设计涉及受限离子液体的应用，例如电池、太阳能电池和润滑剂。该教育计划由三个主要部分组成，重点是学生的研究监督、教学、指导以及与项目研究部分相结合的外展活动。这些组成部分包括（i）开发一门由 PI 教授的关于软物质界面现象的新研究生课程，（ii）指导研究中代表性不足的本科生，以及（iii）向公众传播项目成果在阿克伦地区，少数族裔占总人口的 25%，该地区的公众通过 NSF 资助的教育电子设备开发拨款，依靠与当地高中教师建立的联系。

项目成果

Dual-functional core-shell electrospun mats with precisely controlled release of anti-inflammatory and anti-bacterial agents

双功能核壳电纺垫，可精确控制抗炎和抗菌剂的释放

• DOI: 10.1016/j.msec.2019.02.076
• 发表时间: 2019-07
• 期刊: Materials Science and Engineering: C
• 作者: Wen, Shihao;Hu, Yupeng;Zhang, Yuanzhong;Huang, Shifeng;Zuo, Yuchen;Min, Younjin
• 通讯作者: Min, Younjin