Collaborative Research: Line-Active Amphiphiles for Nanostructure Stability

该项目旨在促进对如何使用线活性分子（我们称之为linactants）来修改分子单层内纳米和中观尺度特征的线张力的基本理解。控制线张力的能力对于使用下一代纳米光刻方法创建的物体的稳定性至关重要；此外，溶解剂将允许创建自组织的2D特征，类似于3D胶束或微乳液。该策略将基于Langmuir-Blodgett （LB）沉积和相关自组装方法制备的双组分和三组分单分子膜内的分子聚集。关键组成部分包括合理设计和合成具有线活性的分子物种，这些分子物种在三维（3D）胶束、双层和微乳液中起着类似于两亲性表面活性剂分子的二维（2D）作用。与三维表面活性剂具有疏水性和亲水性区域的方式相同，这些活性剂分子将具有两条分子“尾巴”；每条尾巴都将与其他化学性质不同的单层成分相互作用。一种方法将涉及具有一种碳氢化合物和一种化学和/或结构不同尾部（例如，部分氟化）的双尾二维溶剂。具体实验包括线活性的系统表征（线张力等温线），二维乳状液的动力学稳定性，以及两组分和三组分单层相图的探索。这个合作研究项目包括两所不同大学的两个不同学科，旨在扩大妇女和少数民族对科学和教育的参与。拟议的同事包括三名女性（一名本科生和两名研究生）和两名少数族裔（一名本科生和一名研究生）。我们鼓励所有参与者加入当地的专业协会，并参加地方和国家会议，以促进我们的传播工作。随着器件和材料的小型化，表面和界面的影响变得越来越重要。特别是，表面张力的影响会导致不稳定性，如凝固或纳米级图案的降解。由于这个原因，纳米级结构的制造需要添加分子稳定剂——在表面分裂并降低表面张力的分子。对于传统的三维材料，如胶体和乳剂，这种稳定剂背后的科学原理是相当好理解的。然而，对于稳定二维纳米结构（即在表面上制造的纳米级图案）所必需的分子，没有这样的科学存在。这种表面纳米图案的稳定性是未来分子电子学和生物传感器技术应用所必需的。本项目将寻求一种合理的方法来发展这门表面纳米结构稳定科学。这个合作研究项目包括两所不同大学的两个不同学科，旨在扩大妇女和少数民族对科学和教育的参与。

This project aims to advance a fundamental understanding of how line-active molecules (which we call linactants) can be used to modify the line tension of nano- and meso-scale features within molecular monolayers. The ability to control line tension will be critical to the stabilization of objects created using next generation nanolithographic methods; in addition, linactants will permit the creation of self-organized 2D features that are analogous to 3D micelles or microemulsions. The strategy will be based on molecular aggregation within two- and three-component monomolecular films prepared by Langmuir-Blodgett (LB) deposition and related self-assembly methods. Key components include the rational design and synthesis of line-active molecular species that play a two-dimensional (2D) role analogous to that of amphiphilic surfactant molecules in three-dimensional (3D) micelles, bilayers, and microemulsions. In the same manner in which a 3D surfactant possesses hydrophobic and hydrophilic regions, these linactant molecules will possess two molecular "tails"; each tail will interact favorably with one of the other chemically dissimilar monolayer components. One approach will involve two-tailed 2D linactants having one hydrocarbon and one chemically and/or structurally dissimilar tail (e.g., partially fluorinated). Specific experiments include the systematic characterization of line activity (line tension isotherms), kinetic stabilization of 2D emulsions, as well as the exploration of two- and three-component monolayer phase diagrams. This collaborative research project, which encompasses two distinct disciplines at two separate universities, seeks to broaden the participation of both women and minorities in science and education. Proposed co-workers include three women (one undergraduate and two graduate students) and two minorities (one undergraduate and one graduate student). All participants will be encouraged to join their local professional societies and to attend local and national meetings to advance our dissemination efforts. As devices and materials are made smaller and smaller, the influence of surfaces and interfaces becomes increasingly important. In particular, the influence of surface tension leads to instabilities, such as coagulation or the degradation of nanoscale patterns. For this reason, the fabrication of nanoscale structures requires the addition of molecular stabilizers -- molecules that partition at surfaces and reduce the surface tension. The science behind such stabilizers is reasonably well understood for traditional three-dimensional materials, such as colloids and emulsions. However, no such science exists for molecules that are necessary to stabilize two-dimensional nanostructures (i.e., nanoscale patterns fabricated on surfaces). The stability of such surface nanopatterns is required for future applications in molecular electronics and biosensor technologies. This project will pursue a rational approach to develop this science of surface nanostructure stabilization. This collaborative research project, which encompasses two distinct disciplines at two separate universities, seeks to broaden the participation of both women and minorities in science and education.