Probing the Role of Surface Defects and Disorder on the Tribology of Nanoscopic Contacts

据估计，在美国，由于粘附、摩擦和磨损机制造成的能量损失，每年损失1000亿美元。 该奖项支持的研究目标是对天然和有机硅烷官能化氧化物表面的缺陷成核（例如键断裂和分子堆积缺陷）如何影响界面的摩擦，粘附和磨损有一个清晰的认识。 将使用原子力显微镜（AFM）研究二氧化硅和氧化铝等材料的磨损。这些研究将使我们能够在原子尺度上直接跟踪缺陷成核，并开发磨损预测模型。 此外，由于滑动接触中真实的表面之间的摩擦和粘附由纳米尺度表面粗糙体（ca. 10 - 50 nm），将开发基于可控尺寸的二氧化硅纳米颗粒的测量平台。AFM针尖与这些明确定义的表面粗糙的相互作用将很容易模仿在真正的粗糙-粗糙接触处发现的条件，允许确定在不同环境条件下粗糙尺寸对有机硅烷基润滑剂的功效的影响。如果成功，这项工作将指导新的分子基润滑剂的工程设计，并提高微器件的设计能力。 参与该项目的学生将在对美国技术竞争力持续发展至关重要的领域获得广泛的教育和培训，包括材料科学，工程和表面化学。 这项工作将通过PI和学生通过非正式的公共科学讲座，会议和部门研讨会进行广泛传播。 培训将通过与NIST等国家实验室的合作得到加强，为学生提供多样化的教育体验。 这项工作的各个方面也将被纳入为小学生的示范和化学，材料科学和工程学生的研究生水平的仪器方法靴子营地。

It has been estimated that $100 billion is lost annually in the US due to energy losses through mechanisms of adhesion, friction and wear. The objective of the research supported by this award is to generate a clear understanding of how defect nucleation (e.g. bond breaking and molecular packing defects) at native and organosilane functionalized oxide surfaces, influences friction, adhesion and wear of interfaces. Wear of materials such as silica and alumina will be studied using atomic force microscopy (AFM). These studies will enable us to directly follow defect nucleation on the atomic scale and develop predictive models for wear. Additionally, as friction and adhesion between real surfaces in sliding contact are dominated by the interactions of nanoscaled surface asperities (ca. 10 50 nm), a measurement platform based on silica nanoparticles of controlled size will be developed. The interactions of an AFM tip with these well defined surfaces asperities will readily mimic the conditions found at true asperity-asperity contacts, allowing for the influence of asperity size on the efficacy of organosilane based lubricants under varying environmental conditions to be determined. If successful, this work will guide the engineering of new molecular based lubricants and enhance microdevice design capabilities. Students participating in the project will gain broad education and training in areas critical for the continued development of US technological competitiveness, including materials science, engineering and surface chemistry. The work will be disseminated broadly through presentations by the PI and students via informal public science talks, conferences and departmental seminars. Training will be augmented by collaborations with national labs such as NIST, providing students with a diverse educational experience. Aspects of the work will also be incorporated as demonstrations for elementary school students and in a graduate level instrumental methods boot camp for chemistry, materials science and engineering students.