Model Studies of Reversibly Interacting Surfaces

PI建议研究表面和界面之间的相互作用，在这些表面和界面上添加了表征良好的黏附分子分布。这些分子基于嵌段共聚物，该嵌段共聚物由位于固/液或液/液界面的疏水和亲水部分组成。实验旨在研究水介质中两个这样的界面之间的各种吸引人的相互作用。这些吸引人的相互作用是可逆的，并且是由连接到嵌段共聚物的亲水部分的官能团之间的特定相互作用产生的。拟议的实验包括研究连接到聚合物链末端的官能团之间的疏水相互作用，连接到聚合物链末端的官能团之间的氢键相互作用，以及生物物理界已经很好地表征的模型受体/配体对之间的强氢键相互作用。这些实验将确定单个黏附分子的集合力如何在带有多个黏附基团的表面之间产生可量化的吸引人的相互作用。拟议的研究将定义表面的作用、粘附剂分子的空间分布(均匀分布或聚集)的影响以及粘附剂分子在平面界面上的横向迁移率。已经设计了一系列接触实验，它们对跨越几个数量级的界面相互作用能很敏感。这项研究提供了分子水平的信息和适当设计生物材料或自组装系统所需的信息之间的必要联系，分子水平的信息由于纳米科学和纳米技术的最新进展而变得越来越可用，而生物材料或自组装系统的相关长度尺度通常在微米范围内。实验方法和理论模型的发展将是这项研究的一个重要成果，这些实验方法和理论模型可以用来在“纳米”和“微观”特性之间建立这种联系。西北大学的科学家和他们的合作者还将获得一个微观力学实验室，该实验室具有增强的“软”材料研究能力。此外，研究生和本科生将接受表面科学和力学方面的培训，以及聚合物科学的物理和化学方面的培训。

The PI proposes to study interactions between surfaces and interfaces to which well-characterized distributions of adhesion molecules have been added. The molecules are based on block copolymers consisting of hydrophobic and hydrophilic portions that are localized at a solid/liquid or liquid/liquid interface. Experiments are designed to study a variety of attractive interactions between two such interfaces in aqueous media. These attractive interactions are reversible, and result from specific interactions between functional groups attached to the hydrophilic portions of the block copolymers. Proposed experiments include studies of hydrophobic interactions between functional groups that are attached to the ends of the polymer chains, hydrogen-bonding interactions between functional groups that are attached to the ends of the polymer chains, and strong hydrogen-bonding interactions between a model receptor/ligand pair that has been well-characterized by the biophysics community. The experiments will determine the ways that collective forces from individual adhesion molecules result in quantifiable attractive interactions between surfaces bearing multiple adhesive groups. The proposed research will define the role of the surface, the effects of spatial distribution of adhesive molecules (uniformly distributed or clustered) and the lateral mobility of the adhesive molecules in the plane interface. A series of contact experiments have been designed that are sensitive to interfacial interaction energies spanning several orders to magnitude.The research provides a necessary link between the molecular-level information that is becoming increasingly available as a result of recent advances in nanoscience and nanotechnology, and the information that is needed for the appropriate design of biomaterials or self-assembling systems, where the relevant length scales are often in the micron range. Development of experimental methods and theoretical models that can be utilized to make this connection between 'nanoscopic' and 'microscopic' properties will be an important outcome of this research. A micromechanics laboratory with enhanced capabilities for studies of 'soft' materials will also be available to scientists throughout Northwestern University and the their collaborators. In addition, graduate and undergraduate students will be trained in aspects of surface science and mechanics, and in both physical and chemical aspects of polymer science.