Collaborative Research: Structure and Dynamics of Liquid Interfaces Studied by X-Ray and Neutron Scattering

细胞的许多生物活性发生在细胞膜上。 因此，生物传感器的研究重点是构建支撑在半导体表面上的人工膜。本工作的目标是调查的结构和动态特性的支持膜使用一个复杂的技术称为相干X射线散射。测量结果将用于构建膜运动的流体动力学模型，并确定重要的物理参数，如表面张力，粘度和弹性模量的值。这项研究将开始于支持在基底上的脂质双层，并通过添加中间缓冲层（如纤维素膜）或通过用蛋白质将膜拴在基底上来探测膜从基底上释放时其动力学的变化。该研究成果将对聚合物薄膜在复合材料、粘合剂、包装、生物相容性材料和生物传感器等方面的应用产生重大影响。学生，包括来自代表性不足的群体，将在国家laboratories.Technical AbstractThis项目将研究的结构和动态的液体界面，包括两个聚合物流体界面和脂质双层使用掠入射X-射线散射和X-射线光子相关光谱（XPCS），利用相干X-射线束的使用状态或最先进的同步加速器X-射线设施进行培训。结合粘弹性流体力学的理论处理，本工作将提供分析薄液膜的界面张力、粘度和弹性模量的方法。聚合物薄膜的玻璃化转变温度附近的异常动力学行为将被检查。聚合物的工作将为研究脂质双层膜系统的动力学波动提供起点。在裸露的或无光泽的基底上的水中的支撑膜提供了具有足够表面积的取向膜，以用诸如X射线或中子散射、XPCS或中子自旋回波的技术进行研究。这些层状系统的结构，构象和动力学将被研究，以阐明在各种条件下的膜的粘度和弹性模量。该研究成果将对聚合物薄膜在复合材料、粘合剂、包装、生物相容性材料和生物传感器等方面的应用产生重大影响。学生，包括来自代表性不足群体的学生，将在国家实验室接受使用国家或最先进的同步加速器x射线设施的培训。

Non-Technical AbstractMuch of the biological activity of cells takes place on membranes. Consequently, a focus of research on biosensors is the construction of artificial membranes supported on semiconductor surfaces. The goal of the present work is to investigate the structural and dynamic properties of such supported membranes using a sophisticated technique known as coherent x-ray scattering. The results of measurements will be used to construct hydrodynamic models of membrane motion and to determine the values of important physical parameters such as the surface tension, viscosity and elastic moduli. The research will begin on lipid bilayers supported on a substrate and probe the changes in their dynamics as membranes are freed from the substrate by adding intermediate cushioning layers such as cellulose films, or by tethering the membranes above the substrate with proteins. The results of this research will have significant impact on the application of polymer films in composites, adhesives, packaging, biocompatible materials, and biosensors. Students, including from underrepresented groups, will be trained in the use of state-or-the-art synchrotron x-ray facilities at national laboratories.Technical AbstractThis project will study the structure and dynamics of liquid interfaces including both polymeric fluid interfaces and lipid bilayers using grazing incidence x-ray scattering and x-ray Photon Correlation Spectroscopy (XPCS) which utilizes coherent x-ray beams. Coupled with theoretical treatments of viscoelastic hydrodynamics, this work will provide methods of analyzing the interface tension, viscosity and elastic moduli of thin liquid films. Anomalous dynamical behavior in the vicinity of the glass transition temperature for polymeric films will be examined. The work on polymers will provide the starting point for studies of the dynamical fluctuations in lipid bilayer membrane systems. Supported membranes in water on bare or cushioned substrates provide oriented films of sufficient surface area to study with techniques such as x-ray or neutron scattering, XPCS or neutron spin echo. The structure, conformation and dynamics of these layered systems will be studied to elucidate the viscosities and elastic moduli of membranes under various conditions. The results of this research will have significant impact on the application of polymer films in composites, adhesives, packaging, biocompatible materials, and biosensors. Students, including from underrepresented groups, will be trained in the use of state-or-the-art synchrotron x-ray facilities at national laboratories.