Dynamic and Non-Equilibrium Aspects of Polymer Adsorption

聚合物吸附的动态和非平衡方面由于吸附引起的剧烈表面修饰，柔性大分子在固体上的吸附在许多技术中起着重要作用。研究将使用四种具有分子级灵敏度的原位技术：荧光光谱、超声波石英晶体谐振器、中子反射和图案光漂白，在具有良好表征的表面上吸附柔性线性均聚物。这些方法将允许对吸附层中的基本动态过程进行系统的研究：渗透关系（即溶胀崩塌）和单个被吸附聚合物的平移扩散。他们还将阐明控制吸附动力学和聚合物在吸附相和体相之间交换的机制。实验将辅以计算机模拟，提供机理的洞察，结果将为吸附层的操作和控制提供新的指导，使各种技术受益。例如，依靠胶体悬浮液的技术，吸附会影响悬浮液的稳定性和流变性；挤压和成型操作，机器表面的吸附会影响流动稳定性和污垢；以及生物医学技术，涉及假肢和血液接触装置，生物聚合物吸附控制血栓形成和细胞粘附。

CTS-9634594 Durning, Turro-Columbia University SUMMARY DYNAMIC AND NON-EQUILBRIUM ASPECTS OF POLYMER ADSORPTION The adsorption of flexible macromolecules onto solids plays an important role in many technologies because of the dramatic surface modifications caused by the adsorption . Research will be performed on flexible, linear homopolymers adsorbing on well-characterized surfaces using four in-situ techniques with molecular-level sensitivity: fluorescence spectroscopy, ultrasonic quartz crystal resonators, neutron reflection, and pattern photobleaching. These methods will allow a systematic study of elementary dynamic processes in adsorbed layers: osmotic relation (i.e., swelling collapse) and translational diffusion of individual adsorbed polymers. They will also clarify the mechanisms controlling adsorption kinetics and exchange of polymers between adsorbed and bulk phases. The experiments will be supplemented by computer simulations, providing mechanistic insight , The results will supply new guidelines for manipulation and control of adsorbed layers, benefiting a variety of technologies. Examples include technologies relying on colloidal suspensions where adsorption affects suspension stability and rheology, extrusion and molding operations where adsorption on machine surfaces affects flow stability and fouling, and in biomedical technologies involving prosthetic and blood contacting devices where biopolymer adsorption controls thrombosis and cell adhesion.