Tailored Interfaces with Amphiphilic Polymers

CTS-9616797研究嵌段共聚物的结构和性质，其中一个嵌段是不吸附的聚电解质，另一个嵌段是吸附疏水的嵌段。其目标是学习如何在水环境中的衬底上创建聚合物层，使固体界面具有有用的特性。感兴趣的特性可能包括粘附性、摩擦力、颗粒和细胞沉积、表面电荷、膨胀、水化和硬度。这项工作将影响的技术领域从印刷和涂层中的颗粒水分散体，到生物材料、药物输送和生物技术中出现的生物界面。所提出的工作将基于与上述描述相对应的几个系列疏水改性聚电解质的合成。合成将受到控制，以在每个区块中产生明确定义的分子量的系统变化，并使用各种化学物种，从而能够在链段亲水性、线电荷密度、淬火和退火电荷位的数量、分子结构和链灵活性方面进行可控的变化。对溶液制备方法和性质的仔细研究是这项工作的一个基本特点，因为我们预计表面层的性质会受到制备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，并将通过原位椭偏测量法进行实时跟踪，并通过中子反射和相关方法对层进行探索性研究。通过使用表面力装置直接测量这些层之间的相互作用力，将获得这些层的性质以及其他结构信息。两层之间的摩擦力将通过安装在表面力仪器上的侧向力测量装置来研究。在这项拟议的工作结束时，我们将开发出一系列数据，使用聚合物两亲性装饰的水界面的预测性设计成为可能。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，以及具有特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表现。对这些性质的理解将需要更好的聚电解质物理知识，这项工作将对此做出贡献，并为参与软材料和复杂流体开发和处理的工程师提供大量有用的数据。

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.