Tailored Interfaces with Amphiphilic Polymers

摘要：本课题旨在探讨嵌段共聚物吸附层的结构和性能，其中一个嵌段为非吸附聚电解质，另一个嵌段为吸附疏水嵌段。目的是学习如何在水环境中在基材上创建聚合物层，从而赋予固体界面有用的特性。感兴趣的特性可能包括附着力、摩擦、颗粒和细胞沉积、表面电荷、膨胀、水合作用和硬度。这项工作将影响的技术领域包括从印刷和涂层中颗粒的水性分散到生物材料、药物输送和生物技术中产生的生物界面。所提出的工作将基于合成与上述描述相对应的几个系列疏水改性聚电解质。合成过程将被控制，以在每个区块中产生定义良好的分子量的系统变化，并与各种化学物质一起，使片段亲水性、线性电荷密度、淬火与退火电荷位点的数量、分子结构和链柔韧性的变化得到控制。仔细研究溶液制备方法和性质是这项工作的基本特征，因为我们预计表层的性质会受到制备它们的溶液的性质和历史的强烈影响。这些分子的吸附将在不同的溶液条件下进行，并将通过原位椭偏仪实时跟踪，并通过中子反射和相关方法对层进行探索性研究。这些层的性质和额外的结构信息将通过使用表面力装置直接测量层之间的相互作用力来获得。层之间的摩擦力将通过附着在表面力仪器上的横向力测量来研究。在这项工作的结论，我们将开发出一个数据体，能够预测设计用聚合物两亲体装饰的水界面。我们将确定这些聚合物的吸附如何取决于分子结构和溶液性质，以及具有一定分子量和链密度的吸附层在法向和摩擦力相互作用下的行为。对这些特性的理解将需要对聚电解质物理的进一步了解，这项工作将有助于提高这方面的知识，并为参与软材料和复杂流体开发和处理的工程师提供有用的数据体。

ABSTRACT CTS-9616797 This proposal aims to explore the structure and Properties of adsorbed layers of block copolymers in which one block is a nonadsorbing polyelectrolyte and the other block is an adsorbing hydrophobic block. the objective is to learn how to create layers of polymers on substrates in aqueous environments that confer useful properties on the solid interfaces. Properties of interest might include adhesion, friction, particle and cellular deposition, surface charge, swelling, hydration and hardness. The technological areas that this work will influence range from aqueous dispersions of particles, as in printing and coating, to biointerfaces, arising in biomaterials, drug delivery and biotechnology. The proposed work will be based on the synthesis of several series of hydrophobically modified polyelectrolytes corresponding to the above description. The synthesis will be controlled to produce systematic variations of well-defined molecular weights in each of the blocks, and with a variety of chemical species enabling controlled changes in segment hydrophilicity, linear charge density, populations of quenched vs. annealed charge sites, molecular architecture and chain flexibility to be explored. Careful investigation of the solution preparation methods and properties is an essential feature of this work, since we anticipate that the properties of the surface layers can be strongly affected by the nature and history of the solutions from which they are prepared. Adsorption of these molecules will be conducted under varying solution conditions and will be followed in real time by in situ ellipsometry, supported by exploratory studies of the layers by neutron reflection and related methods. Properties of these layers, and additional structural information will be obtained by direct measurement of forces of interaction between the layers using the surface forces apparatus. Frictional forces between the layers will be studied via a lateral force measurement attachment t o the surface forces instrument. At the conclusion of this proposed work, we will have developed a body of data enabling the predictive design of aqueous interfaces decorated with polymeric amphiphiles. We will determine how the adsorption of these polymers depends on molecular structure and solution properties, and, how an adsorbed layer of a certain molecular weight and chain density behaves with respect to normal and frictional force interactions. The understanding of these properties will require an improved knowledge of polyelectrolyte physics, to which this work will contribute, as well as providing a body of data useful to engineers involved in the development and processing of soft materials and complex fluids.