The Performance of Customized Molecular Coatings

Cts-9615868 Quinn，J./Vanderlick，T.R.U of Penn项目总结通过利用某些有机分子自发组织的愿望，有可能设计和制造具有独特结构的定制分子涂层。一种这样的涂层工艺是朗缪尔-布洛杰特(LB)沉积技术，这是一种用于构建多层分子膜的机械方法。另一种方法是“自组装单分子膜(SAM)”，这是一种基于溶液化学吸附的化学方法。在过去的十年里，在扩大成膜分子的集合和表征所得到的涂层的结构方面做出了大量的努力。另一方面，在评估这些定制的分子涂层在不同应用中的性能，或它们对环境变化的响应方面，几乎没有什么努力。测量和了解这些有机涂层与其环境相互作用的方式是本提案的中心重点。实验的目的是检查涂层在接触到不同气体、液体和固体时的表现。这项工作分为两个分支。第一个中心是研究具有不可忽略体积的涂层的吸收特性(由LB方法形成)，将它们的性能确定为“分子海绵”。这里，将从生物膜中获得线索来设计具有不同传输特性的膜。此外，还将开发一种新的方法(使用轨道刻蚀云母)来测量沿着组成LB膜的地层/在其内部的传输。这项提案的另一个分支涉及非分子薄膜的性能。不同分子设计的涂层将使用来自两个不同品种的自组装单分子膜-众所周知的烷烃-硫醇体系和一类新的基于芳香硫醇的成膜分子来制备。将研究自组装膜在不同表面(包括其他自组装膜)上的附着力，从而评价这些涂层的性能和响应性。我们还将研究不同涂层的吸附特性，以确定它们作为“分子粘贴纸”的性能。这项工作的一个关键目标是比较这些不同单层形成系统的行为。这里提出的研究将利用两个强大的工具：表面力仪器测量表面之间的相互作用力，和石英晶体微天平测量质量拾取。尽管许多研究小组目前正在研究自组装单层膜，但这种方法的独特之处在于所采用的技术(特别是SFA)和建议研究的系统(包括新类别的SAM)

CTS-9615868 Quinn, J./Vanderlick, T.R. U of Penn Project Summary By exploiting the desire of certain organic molecules to spontaneously organize, it is possible to design and fabricate customized molecular coatings with unique architectures. One such coating process is the Langmuir-Blodgett (LB) deposition technique, a mechanical method used to build multi-layered molecular films. Another process is "self-assembled monolayer (SAM) formation," a chemical method based on chemisorption from solution. Over the last decade, substantial effort has been directed at expanding the sets of film forming molecule and characterizing the structure of the resultant coatings. On the other hand, little effort has been spent on evaluating the performance of these customized molecular coatings in different applications, or their response to changes in their surroundings. Measuring and understanding the ways in which these organic coatings interact with their environment is the central focus of this proposal. Experiments are designed to examine how coatings behave to the presence of different gases, liquids, and solids with which they come into contact. This work is divided into two branches. The first centers on the absorption characteristics of coatings with non-negligible volume (as formed from the LB method), establishing their performance as "molecular sponges" Here, cues will be taken from biological membranes to design films with different transport properties. Also, a novel method (using track-etched mica) will be developed to measure transport along/within the strata which comprise the LB films. The other branch of this proposal deals with the performance of nonmolecular films. Coatings of different molecular design will be fabricated using self-assembled monolayers derived from two different breeds-the well-known alkane-thiol based systems and a new class of film forming molecules based on aromatic thiols. The adhesion of SAMs to various surfaces(including other SAMs) will be investigated, thus evaluating the performance and reponsiveness of these coatings "molecular glue." The adsorption characteristics of different coatings will also be investigated, establishing their performance as "molecular tack-paper." A key objective of this work is compare the behavior of these different monolayer forming systems. The studies proposed herein will take advantage of two powerful tools: the surface forces apparatus to measure the forces of interaction between surfaces, and the quartz crystal microbalance to measure mass pickup. Although many groups are currently investigating self-assembled monolayers, the uniqueness of this approach rests both on techniques employed( in particular the SFA) and on systems proposed for study(including the new Class of SAMs)