GOALI: Dynamic Behavior of Preferentially Adsorbed Block Copolymer Brushes

本建议中概述的工作将研究多嵌段共聚物层的性质，这些多嵌段共聚物通过一个嵌段优先吸附在表面上，而留下另一个嵌段(S)不被吸附。主要目的是了解如何控制这些结构形成层的剪切性能，以构建具有定制摩擦性能和磨损特性的聚合物改性表面。控制聚合物表面的摩擦性能直接影响到从润滑和胶体稳定到表面活性聚合物的新应用等技术领域，包括显示设备、微阀和传感器。本建议中描述的工作形成了一个连贯的计划，以系统地研究溶剂质量、剪切速率和层组成对各种聚合物/溶剂对的动态响应的影响。必要的聚合物材料的合成和表征将通过与伯明翰阿拉巴马大学的吉米·梅斯博士合作进行。安装在克莱姆森大学的一台改装的表面力仪器将被用来直接测量滑动两个聚合物涂层表面横向通过彼此所需的力。这些测量是在分子长度尺度上进行的，因此，提供了关于表面之间分子水平摩擦相互作用的信息。关于分子量、链结构和溶液性质的变化如何影响这些界面层的动态行为的累积数据，对于开发用两亲性大分子修饰的表面进行预测设计的能力是至关重要的。这项工作还将产生更完整的聚合物刷子的结构-性能数据，这将对软材料表面改性的开发和工程普遍有用。

ABSTRACTCTS-9816147Clemson Univ./S. KilbeyThe work outlined in this proposal will investigate the properties of layers of multiblock copolymers that are preferentially adsorbed in a surface through one block, leaving the other block(s) non-adsorbed. The primary objective is to understand how to manipulate the shear properties of these structure-forming layers in order to build polymer-modified surfaces with tailored frictional properties and wear characteristics. Manipulating the frictional properties of polymer-modified surfaces directly impact areas of technology ranging from lubrication and colloid stabilization to novel applications for surface active polymers, including display devices, microvalves, and sensors. The work described in this proposal forms a coherent plan to systematically investigate the impact of solvent quality, shear rate, and layer composition on the dynamic response of various polymer/solvent pairs. The synthesis and characterization of the necessary polymeric materials will be handled through a collaboration with Dr. Jimmy Mays of the University of Alabama at Birmingham. A modified Surface Forces Apparatus housed at Clemson University will be used to directly measure the forces required to slide two polymer coated surfaces laterally past each other. These measurements are done on molecular length scales and therefore, provide information on the molecular-level frictional interactions between the surfaces. The accumulated data on how the dynamic behavior of these interfacial layers are impacted by changes in molecular weight, chain architecture, and solution properties are central to developing the capability to do predictive design of surfaces modified with amphiphilic macromolecules. This work will also result in a more complete body of structure-property data of polymer brushes, which will be generally useful for the developing and engineering of surfaces modified by soft materials.