SGER: Hydrophobic Forces in Particle Adhesion

abstractcts - 04014019。疏水力在水环境中粒子与表面粘附中的作用还没有得到充分的了解。有必要收集数据，使疏水效应得以量化，并发展理论来描述这种效应。在这项工作中，原子力显微镜将用于直接测量水溶液中颗粒和基质之间的附着力。在测量附着力之前和之后，将测量基材的粗糙度和颗粒的粗糙度和几何形状。颗粒和衬底的弹性性能也将被确定。有了这些信息，亚利桑那州立大学的Beaudoin实验室开发的粒子粘附模型将用于量化作用在这些系统中的范德华（vdW）和静电（ES）相互作用力。这些模型考虑了变形和非均匀几何形态对粘接的影响。在评估了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。在这种方式下，一个系统的实验研究的疏水相互作用力的一些不同大小和几何形状的粒子相互作用与一些表面将被执行。接触角测量将在与粘附研究中使用的颗粒和衬底成分相同的平板材料上进行，以便将粘附研究中涉及的材料的界面能量化。这些数据将为粒子和表面之间疏水相互作用的系统评价提供基础。一旦确定了疏水力对粒子相互作用影响的形式和大小，就有可能发展出适当的理论来描述这些影响。这项工作的智力优势在于使用原子力显微镜测量水溶液中可变形、粗糙、不均匀颗粒与可变形、粗糙表面的粘附性，并使用最近开发的、实验验证的模型来描述这些颗粒粘附中的vdW和ES力。这将使这些系统的疏水力被隔离。在这种方式下，真实的粒子-表面相互作用力可以在测量技术的最小混淆效应下进行测量，并且可以隔离疏水力。由此产生的数据集将提供对颗粒粘附的疏水效应的全面视图，这将作为模型开发的基础。拟议工作的更广泛影响在于加强对高技术应用光谱中的vdW， ES和疏水力的理解的重要性。理解和控制这些力的相对强度将对医疗植入物的清洁和灭菌、半导体加工过程中晶圆的清洁、高性能应用的低污染涂层的设计以及在微机电系统（MEMS）制造过程中以最小的污染物水平生产高度工程化表面的新方法的开发产生深远的影响。研究结果将在粘附学会、NSF/SRC环境友好型半导体制造中心、美国化学工程师学会和电化学学会的会议上发布。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.