SGER: Hydrophobic Forces in Particle Adhesion

摘要CTS-04014019S。Beaudoin，Purdue大学疏水力在水环境中颗粒粘附到表面的作用还没有得到充分的理解。 有必要收集的数据，将允许量化的疏水效应，也为理论的发展来描述这种效果。 在这项拟议的工作中，原子力显微镜将被用来直接测量粒子和感兴趣的基板在水溶液中的粘附力。 在测量粘附力之前和之后，将测量基底的粗糙度以及颗粒的粗糙度和几何形状。 还将测定颗粒和基底的弹性性质。 有了这些信息，在亚利桑那州州立大学的Beaudoin实验室开发的颗粒粘附模型将被用来量化的货车德瓦尔斯（vdW）和静电（ES）在这些系统中的相互作用力。 这些模型考虑了变形和不均匀的几何形状和形态对粘附力的影响。 在评估vdW和ES力之后，这些系统中的剩余力将主要归因于疏水现象。 以这种方式，将对许多不同尺寸和几何形状的颗粒与许多表面相互作用的疏水相互作用力进行系统的实验研究。 接触角测量将在具有与粘附研究中使用的颗粒和基底相同的组成的材料的平板上进行，以便量化粘附研究中涉及的材料的界面能。 这些数据将为系统评价颗粒和表面之间的疏水相互作用提供基础。 一旦确定了疏水力对颗粒相互作用的影响的形式和大小，就有可能发展适当的理论来描述这些影响。 在这项拟议的工作中的智力价值在于在测量的可变形的，粗糙的，不均匀的颗粒变形，粗糙的表面在水溶液中使用原子力显微镜，和使用最近开发的，实验验证的模型来描述VDW和ES力在这些颗粒的粘附力。 这将允许疏水力被隔离用于这些系统。 以这种方式，现实的颗粒表面相互作用力可以测量与最小的干扰影响，从测量技术，和疏水力隔离。 由此产生的数据集将提供一个全面的观点，疏水效应的颗粒粘附，将作为模型开发的基础。 更广泛的影响，拟议的工作在于在一系列高科技应用中，提高对vdW，ES和疏水力的理解的重要性。 了解和控制这些力量的相对强度将有一个深刻的影响，医疗植入物的清洁和消毒，在半导体加工过程中的晶片的清洁，低污染涂层的高性能应用的设计，并在微机电系统（MEMS）的制造过程中生产高度工程化的表面与最小的污染物水平的新方法的发展。 研究结果将在粘附学会、NSF/SRC环境友好半导体制造中心、美国化学工程师学会和电化学学会的会议上分发。 研究结果将发表在《粘附杂志》上。

AbstractCTS-04014019S. Beaudoin, Purdue UniversityThe role of hydrophobic forces in particle adhesion to surfaces in aqueous environments is not adequately understood. There is a need for the collection of data that will allow the hydrophobic effect to be quantified, and also for the development of theory to describe this effect. In this proposed work, atomic force microscopy will be used to measure directly the adhesion between particles and substrates of interest in aqueous solutions. The roughness of the substrate and the roughness and geometry of the particles will be measured before and after the adhesion forces are measured. The elastic properties of the particles and substrates will also be determined. With this information, particle adhesion models developed in the Beaudoin lab at Arizona State University will be used to quantify the van der Waals (vdW) and electrostatic (ES) interaction forces acting in these systems. These models take into account the effects of deformation and nonuniform geometry and morphology on the adhesion. After the vdW and ES forces are evaluated, the remaining forces in these systems will be attributed primarily to hydrophobic phenomena. In this fashion, a systematic experimental investigation of the hydrophobic interaction force for a number of particles of different size and geometry interacting with a number of surfaces will be performed. Contact angle measurements will be performed on flat sheets of material with the same composition as the particles and substrates used in the adhesion studies, so that the interfacial energies of the materials involved in the adhesion studies will be quantified. This data will provide the basis for a systematic evaluation of hydrophobic interactions between particles and surfaces. Once the form and magnitude of the effect of hydrophobic forces on the particle interactions has been established, it will be possible to develop appropriate theory to describe these effects. The intellectual merit in this proposed work lies in the measurement of the adhesion of deformable, rough, nonuniform particles to deformable, rough surfaces in aqueous solution using an atomic force microscope, and the use of recently developed, experimentally-validated models to describe vdW and ES forces in the adhesion of these particles. This will allow hydrophobic forces to be isolated for these systems. In this fashion, realistic particle-surface interaction forces can be measured with minimal confounding effects from the measurement technique, and the hydrophobic force isolated. The resulting data set will provide a comprehensive view of hydrophobic effects on particle adhesion that will serve as the basis for model development. The broader impacts of the proposed work lie in the importance of enhanced understanding of vdW, ES, and hydrophobic forces in a spectrum of high technology applications. Understanding and controlling the relative strengths of these forces will have a profound impact on the cleaning and sterilization of medical implants, the cleaning of wafers during semiconductor processing, the design of low-fouling coatings for high performance applications, and the development of new approaches for producing highly engineered surfaces with minimal contaminant levels during the fabrication of microelectromechanical systems (MEMS). The results will be disseminated at meetings of the Adhesion Society, the NSF/SRC Center for Environmentally-Benign Semiconductor Manufacture, the American Institute of Chemical Engineers, and the Electrochemical Society. The results will be published in the Journal of Adhesion.