Dynamics At or Near Interfaces

界面处或界面附近的动力学

• 批准号: 0072898
• 负责人: Peter Green
• 金额: $ 31.5万
• 依托单位: University of Texas at Austin
• 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: 2000-05-15 至 2006-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0072898&HistoricalAwards=false
• 关键词: Dynamics; Near; Interfaces

In thin polymer films, effects due to confinement and to interfacial interactions are responsible for different physical phenomena not generally encountered in bulk materials. These effects include changes in the glass transition temperatures of polymers with decreasing film thickness and changes in the critical phase separation temperatures of A/B polymer blends with film thickness. This proposal has two general goals. In the first, an understanding of the nature of the interactions between polymers and surfaces and the manner in which these interactions affect properties such as local friction, viscosity and translational dynamics of chains is developed. Long and short-range intermolecular forces can have a destabilizing effect on polymer thin films and these effects, together with enthalpic and entropic interactions, influence the stability of thin film polymer blends in ways that are not well understood. The second part of this proposal examines these effects in homopolymer/homopolymer blends and in copolymer/homopolymer blends.In the future, polymer thin films will play an increasingly important role in technologies that, historically, have not involved the use of "soft" materials. Technologies include organic light emitting diodes, sensors, such as electronic noses, and whole cell adhesion sensors. In each of these technologies, specific properties of the polymer are critical. For example, in organic light emitting diodes the electronic and optical properties of the polymer are important whereas for the whole cell adhesion sensors the ability to "tune" adhesive properties of the polymer is critical. The advantage of using polymer thin films over non-polymeric materials in some technologies is that polymers are cheap and easy to fabricate. Moreover, it is potentially easier to "tailor" properties of polymers because of the wide range of molecules that can be synthesized. A fundamental understanding of the properties of polymer thin films will be necessary for the overall success of the use of "soft" materials in many future technologies.

在薄的聚合物薄膜中，由于限制和界面相互作用的影响是负责不同的物理现象，通常不会遇到散装材料。 这些影响包括随着膜厚度的减小聚合物的玻璃化转变温度的变化和随着膜厚度的增加A/B聚合物共混物的临界相分离温度的变化。 这项建议有两个总的目标。 在第一，理解聚合物和表面之间的相互作用的性质和方式，这些相互作用影响的性质，如局部摩擦，粘度和链的平移动力学的发展。 长程和短程分子间力可以对聚合物薄膜具有不稳定作用，并且这些作用与双折射和熵相互作用一起以尚不清楚的方式影响薄膜聚合物共混物的稳定性。 本提案的第二部分研究了均聚物/均聚物共混物和共聚物/均聚物共混物中的这些效应。在未来，聚合物薄膜将在历史上不涉及使用“软”材料的技术中发挥越来越重要的作用。 技术包括有机发光二极管、传感器（如电子鼻）和全细胞粘附传感器。 在这些技术中的每一种中，聚合物的特定性质是关键的。 例如，在有机发光二极管中，聚合物的电子和光学性质是重要的，而对于全细胞粘附传感器，“调节”聚合物的粘附性质的能力是关键的。 在某些技术中使用聚合物薄膜优于非聚合物材料的优点在于聚合物便宜且易于制造。 此外，由于可以合成的分子范围很广，因此可能更容易“定制”聚合物的性质。 对聚合物薄膜性质的基本理解对于在许多未来技术中使用“软”材料的全面成功是必要的。