Formation Kinetics of Tethered Nanolayers: Real-Time Studies with Model Polymers

系留纳米层的形成动力学：模型聚合物的实时研究

• 批准号: 9911181
• 负责人: Lynn Penn
• 金额: $ 18万
• 依托单位: University of Kentucky Research Foundation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-04-01 至 2003-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9911181&HistoricalAwards=false
• 关键词: Formation; Kinetics; Tethered; Nanolayers; Real

ABSTRACT CTS-9911181 Lynn Penn, U. of Kentucky Tethered polymer layers provide a unique avenue for tailoring solid surfaces and the interfaces made from them. Precise control of not only the chemical structure and architecture of the tethered polymer, but also of its molecular weight, dispersity, and surface attachment density offers the possibility of similarly precise control of the physicochemical characteristics of the layer and therefore of the performance of the solid surface. Such precisely controlled layers have great potential value in additional areas, including corrosion prevention, friction and wear control, biofouling control, and waste stream purificationTo construct a tethered layer that has the exact characteristics needed for a particular application, the scientist or engineer must be able to manipulate the tethering process with precision. For this to be done, the kinetics and thermodynamics of layer formation must be understood and brought under experimental control. However, the tethering process is made complex by the facts that a) the process involves heterogeneous phase reactions and b) the polymer chains are being attached to a surface that is changing during the process. Furthermore, until recently, there has been no convenient way to monitor the kinetics of formation of a tethered layer. These complexities and difficulties have prevented understanding-based control of the tethering process until the present time.In this project, the kinetic and thermodynamic factors that control layer formation will be explored in terms of specific chemical and physical features of the tethering reaction. These include polymer molecular weight, polymer architecture, and end group-surface interaction. For this, model polymers that provide a wide variation of polymer architecture, molecular weight, and tethering entity will be synthesized by living anionic polymerization. Other quantities that will serve as independent variables are temperature, concentration, solvent (and there interaction between polymer backbone segments and solvent), chemistry of the reactive sites on the solid surface (and thereby interaction between reactive sites and end-functional groups of the polymer chains), and energetics of the solid surface. The tethering reactions of the model polymers to solid surfaces under different conditions will be monitored by means of a recently developed, real-time method based on size-exclusion chromatography.The data obtained from the above studies and the principles that emerge will lead to a comprehensive description of the kinetics of tethering and an evaluation of the thermodynamic factors that influence the process. From this, we will develop of a set of logical guidelines and a general applicable mathematical model of tethering kinetics that can be used for empirical control manipulation of tethered layer structure.

摘要 CTS-9911181 Lynn Penn，肯塔基大学 系留聚合物层为定制固体表面和由其制成的界面提供了独特的途径。 不仅精确控制系链聚合物的化学结构和结构，而且还精确控制其分子量、分散性和表面附着密度，为同样精确控制层的物理化学特性以及固体的性能提供了可能性表面。 这种精确控制的层在其他领域具有巨大的潜在价值，包括腐蚀预防、摩擦和磨损控制、生物污垢控制和废物流净化。要构建具有特定应用所需的确切特性的系留层，科学家或工程师必须能够精确地操纵网络共享过程。 为此，必须了解层形成的动力学和热力学并将其置于实验控制之下。 然而，由于以下事实，束缚过程变得复杂：a) 该过程涉及异相反应，b) 聚合物链附着在过程中不断变化的表面上。 此外，直到最近，还没有方便的方法来监测束缚层形成的动力学。 直到目前，这些复杂性和困难阻碍了对束缚过程的基于理解的控制。在该项目中，将根据束缚反应的特定化学和物理特征来探索控制层形成的动力学和热力学因素。 这些包括聚合物分子量、聚合物结构和端基-表面相互作用。 为此，将通过活性阴离子聚合合成提供多种聚合物结构、分子量和束缚实体的模型聚合物。 用作自变量的其他量包括温度、浓度、溶剂（以及聚合物主链片段和溶剂之间的相互作用）、固体表面上的反应位点的化学性质（以及反应位点和聚合物的末端官能团之间的相互作用）链）和固体表面的能量学。 模型聚合物在不同条件下与固体表面的束缚反应将通过最近开发的基于尺寸排阻色谱的实时方法进行监测。从上述研究中获得的数据和出现的原理将导致束缚动力学的综合描述以及影响该过程的热力学因素的评估。 由此，我们将开发一套逻辑准则和通用的系链动力学数学模型，可用于系链层结构的经验控制操作。