Segmental Dynamics of Surface Bound Polymers

表面结合聚合物的链段动力学

• 批准号: 9807696
• 负责人: Frank Blum
• 金额: $ 24.9万
• 依托单位: Missouri University of Science and Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-07-01 至 2001-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9807696&HistoricalAwards=false
• 关键词: Segmental; Dynamics; Surface; Bound; Polymers

9807696 Blum This award will enable study ofthe segmental motion of polymers at interfaces, particularly those attached to solid surfaces. The interfaces in multiphase materials, such as those in composites, coatings, nano- and electronic materials play an important role in determining the physical properties of those systems. Since the interfaces themselves are quite thin, and as the size of structures is reduced, the effects of the interfaces become even more difficult to properly characterize with macroscopic physical testing. Spectroscopic techniques, especially deuterium nuclear magnetic resonance (NMR), will be used to study the microscopic properties of the polymers at interfaces with solid substrates. The use of deuterium labelling is important because specific deuteration is not a significant perturbation of the segmental motion of the polymer-the deuterons act as reporter groups based on their position which is synthetically controlled. The focus will be on the dynamics (i.e. molecular motion) of polymer segments. Segmental motion has not been studied as much as the structures of the interfacial species; however, both determine the ultimate properties of the systems used. This work builds on work previously funded by NSF where deuterium NMR has been shown to be a powerful tool for probing the motions of adsorbed polymers. For homopolymers adsorbed on solid surfaces, a motional gradient in a single-molecule thick film has been identified. However, the characterization of this gradient/layer was incomplete. It is proposed that experiments on composite materials, where the labelled polymer is adsorbed on the solid substrate and an unlabelled polymer is absorbed over it, be performed. These will identify how the presence of an overlayer affects the interfacial layer. With the sensitivity of the NMR instrumentation available, it is also proposed that two- dimensional exchange NMR experiments be performed in order to quantitatively estimate the rates and amounts of different motional species present in the interfacial polymers. %%% The result of the successful completion of this work will be that knowledge of the structure and dynamics of interfacial materials will help researchers to design interfacial systems with enhanced properties for advanced applications such as advanced composite structures, electronic devices, particle stabilization, and adhesive properties. ***

小行星9807696 该奖项将使研究的链段运动的聚合物在界面，特别是那些连接到固体表面。 多相材料中的界面，如复合材料、涂层、纳米材料和电子材料中的界面，在决定这些系统的物理性质方面起着重要作用。 由于界面本身非常薄，并且随着结构尺寸的减小，界面的影响变得更加难以用宏观物理测试来适当地表征。 光谱技术，特别是氘核磁共振（NMR），将用于研究聚合物在与固体基质的界面处的微观性质。 氘标记的使用是重要的，因为特定的氘化不是聚合物的链段运动的显著扰动-氘核根据其合成控制的位置充当报告基团。 重点将放在聚合物链段的动力学（即分子运动）上。 节段运动还没有被研究尽可能多的界面物种的结构，但是，两者都决定了所使用的系统的最终性能。 这项工作建立在先前由NSF资助的工作基础上，其中氘NMR已被证明是探测吸附聚合物运动的有力工具。 对于吸附在固体表面上的均聚物，已确定在单分子厚膜的运动梯度。 然而，该梯度/层的表征不完整。 建议在复合材料上进行实验，其中标记的聚合物被吸附在固体基质上，而未标记的聚合物被吸附在其上。 这些将确定覆盖层的存在如何影响界面层。 利用NMR仪器的灵敏度，还建议进行二维交换NMR实验，以定量估计界面聚合物中存在的不同运动物种的速率和量。 成功完成这项工作的结果将是，界面材料的结构和动力学知识将有助于研究人员设计界面系统与先进的应用，如先进的复合材料结构，电子器件，颗粒稳定性和粘合性能增强的性能。 ***