Structure and Chemical Interactions at Model Polymer Interfaces

9310151将为两种类型的材料系统产生分子和聚合物界面的结构和化学的Allara关联：1)柔性链分子和聚合物作为薄膜吸附在固体表面上，以及2)无机薄膜，特别是金属，沉积在分子和聚合物表面上。通过使用由具有精确控制的选定官能团阵列的自组装单分子膜制备的定义明确的底物，以及通过应用对单分子层-亚单分子层水平的分子特征敏感的先进的定量表征工具，所有的相关性将被尽可能地定量。钉扎晶格的关键概念，定义为当界面形成时在其上发生吸附或成核的特定位置阵列，将与上述两个系统的实验相关联，并将指导这项工作的进程。在柔性链分子吸附的情况下，将建立关联，将钉扎晶格决定的面内排列与吸附(钉扎)位的化学键(势垒深度)以及与吸附(自组装)链组装相中发展的面外结构相关联的吸附(钉扎)位的迁移性动力学联系起来。这些关联将通过开发一个简单的理论框架来统一，该框架将侧重于试图描述自由体积的分布(缺陷构型)。在金属原子沉积(真空中)的情况下，将建立成核(钉扎)位置(官能团)分布及其化学(金属-有机)与金属薄膜形貌之间的关联。这项特别工作将侧重于由原位红外光谱、x射线光电子能谱和椭圆偏振光谱监测的真空中沉积实验研究，但也将包括与其他机构合作的有限理论研究。上述工作的预期结果是发展了一个连贯的框架，包括理论和实验，用于设计变化广泛的、精确定义的功能化单分子膜，并用于了解从近平衡分子吸附到高放热金属原子化学吸附的各种吸附体上的吸附/化学吸附性质。这项研究将有效地将这些结果与涉及聚合物表面和界面性质的实际材料科学问题联系起来，如粘附性和润湿性，以及聚合物的金属化。***

9310151 Allara Correlations of structure and chemistry at molecular and polymer interfaces will be generated for two types of materials systems: 1) flexible chain molecules and polymers adsorbed as thin films at solid surfaces and 2) inorganic films, specifically metals, deposited (in vacuo) onto molecular and polymer surfaces. All correlations will be driven to be as quantitative as possible by the use of well-defined substrates prepared from self-assembled monolayers with precisely controlled arrays of selected functional groups and by the application of advanced, quantitative characterization tools, sensitive to molecular features at the monolayer-submonolayer level. The key concept of a pinning lattice, defined as the specific array of sites upon which adsorption or nucleation takes place when an interface is formed, interrelates the experiments with the above two systems and will guide the course of this work. In the case of flexible chain molecule adsorption, correlations will be developed which relate the in-plane arrangements, dictated by the pinning lattice, with the chemical bonding (potential well depth) and the associated dynamics of mobility of the adsorption (pinning) sites with the out-of-plane structures which develop in the adsorbed (self- assembled) chain assembly phases. These correlations will be unified by the development of a simple theoretical framework which will focus on attempts to describe the distribution of free volume (defect configurations). In the case of the metal atom deposition (in-vacuo), correlations will be developed which relate the nucleation (pinning) site (functional groups) distributions and their chemistry (metal-organic) to the morphology of the metal films. This particular effort will focus on experimental in-vacuo deposition studies, monitored by insitu infrared spectroscopy, x- ray photoemission and spectroscopic ellipsometry, but also will include limited theoretical studies in collaboration with others. The expected outcome of the above efforts is the development of a coherent framework, both theoretical and experimental, for designing widely varying, precisely defined functionalized monolayers and for understanding the adsorption/chemisorption properties over a wide range of adsorbates from near-equilibrium molecular adsorption to highly exothermic metal atom chemisorption. The research will be designed to efficiently relate these results to practical materials science issues involving polymer surface and interface properties such as adhesion and wetting and to metallization of polymers. ***