Collaborative Research: Line-Active Amphiphiles for Nanostructure Stability

技术总结本研究项目将推进对如何使用线活性分子（在提案中称为linactants）来修改分子单层内纳米和介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，linactants将允许创建类似于3D胶束或微乳液的自组织2D特征。 该策略将基于分子聚集内的两个和三个组件的单分子膜制备的Langmuir-Blodgett（LB）沉积和相关的自组装方法。 关键组成部分包括线活性分子物种的合理设计和合成，这些分子物种在三维（3D）胶束，双层和微乳液中发挥类似于两亲性表面活性剂分子的二维（2D）作用。 以与3D表面活性剂具有疏水和亲水区域相同的方式，这些线性作用物分子将具有两个不同的疏水分子部分（不同的尾部或单个尾部内的嵌段）;每个部分被设计为与相分离的双组分单层膜的相应组分之一有利地相互作用。 这个合作团队以前的工作集中在具有一个烃尾部或嵌段和一个氟化尾部或嵌段的线性反应物上。 这些化合物成功地降低了碳氢化合物和氟碳化合物丰富的单层相之间的线张力;还观察到独特的2D自组装的linactants成纳米级的集群，类似于胶束。 本项目的具体目标是：（1）更深入地了解导致氟碳/碳氢化合物混合单分子层体系中的linactant行为的分子机制;（2）通过设计和合成用于其他二元单分子层混合物（包括碳氢化合物/硅酮、饱和/不饱和碳氢化合物、和胆固醇/脂质。非技术性概述该项目涉及基础科学研究，将使与纳米技术有关的进步。 随着器件和材料越来越小，表面和界面的影响变得越来越重要。 特别地，表面张力的影响导致不稳定性，例如凝结或纳米级图案的降解。 出于这个原因，纳米结构的制造需要添加分子稳定剂-在表面分配并降低表面张力的分子。 对于传统的三维材料，如胶体和乳液甚至纳米颗粒，这种稳定剂背后的科学是相当好理解的。 然而，对于稳定二维纳米结构所必需的分子（即，在表面上制造的纳米级图案）。 这种表面纳米粒子的稳定性是未来在分子电子学、催化剂、生物传感器和生物材料中的应用所需要的。这一合作研究项目包括两所不同大学的两个不同学科，将寻求扩大妇女和少数群体对科学和教育的参与。将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，以推动我们的传播工作。 此外，通过他们参与各种教育和外联方案（例如，雷乌斯，RET，NUE，GAANN，CU发现学习中心，材料科学从CU K-12外展，科罗拉多高中荣誉研究所，休斯顿路易斯斯托克斯少数民族参与联盟，呃拉丁裔外展，韦尔奇暑期学者），研究人员将继续与学生，教师和其他社区成员分享这个项目。 此外，该项目中基础发现和潜在技术影响的整合将提供一个理想的平台，向公众传达研究的兴奋。

TECHNICAL SUMMARYThis research project will advance the fundamental understanding of how line-active molecules (called linactants in the proposal) 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 dissimilar hydrophobic molecular moieties (either distinct tails or blocks within a single tail); each moiety is designed to interact favorably with one of the respective components of a phase-separated two-component monolayer film. Previous work by this collaborative team focused on linactants having one hydrocarbon tail or block and one fluorinated tail or block. These compounds successfully reduced the line tension between hydrocarbon- and fluorocarbon-rich monolayer phases; also observed was distinctive 2D self-assembly of the linactants into nm-scale clusters that were analogous to micelles. The specific objectives of this project are (1) to obtain a deeper understanding of the molecular mechanisms leading to linactant behavior in fluorocarbon/hydrocarbon mixed monolayer systems, and (2) to generalize the linactant phenomenon beyond fluorocarbon/hydrocarbon systems by designing and synthesizing linactants for use in other binary monolayer mixtures, including hydrocarbon/silicone, saturated/unsaturated hydrocarbons, and cholesterol/lipid.NON-TECHNICAL SUMMARYThis project involves fundamental scientific research that will enable advances related to nanotechnology. 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 or even nanoparticles. 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, cataysis, biosensors, and biomaterials. This collaborative research project, which encompasses two distinct disciplines at two separate universities, will seek to broaden the participation of both women and minorities in science and education. All participants will be encouraged to join their local professional societies and to attend local and national meetings to advance our dissemination efforts. Also, through their participation in a variety of educational and outreach programs (e.g., REUs, RET, NUE, GAANN, CU-Discovery Learning Center, Materials Science from CU K-12 outreach, Colorado High School Honors Institute, Houston Louis Stokes Alliance for Minority Participation, UH Latino Outreach, and Welch Summer Scholars), the researchers will continue to share this project with students, teachers, and other community members. Furthermore, the integration of basic discovery and potential technological impact in this project will provide an ideal platform from which to communicate the excitement of research to the public.