GOALI: Understanding Tribological Properties of Thermally-Synthesized Carbon

GOALI学术联络机会奖将支持基础摩擦化学研究，阐明碳材料的摩擦和磨损行为。碳块和涂层广泛用于控制制造过程或制成品中滑动界面的摩擦和磨损。该项目的重点是了解和改善热合成碳(TSC)材料的摩擦化学性质，以满足低摩擦的应用。多晶石墨粉和其他TSC材料表现出相对较高的摩擦力，尽管在石墨和等离子体增强沉积法制备的氢化类金刚石材料的基面上很容易观察到超润滑性。这提出了一个重要的问题--是什么控制了不同类型的碳材料的超润滑性？解决这一问题可以带来更好的碳材料设计，这种材料可用作电机或发电机的碳刷和/或不能使用机油或油脂润滑的机械密封。减少这些部件的摩擦和磨损将极大地提高制造过程中的能效。这些问题对新能源应用非常重要，因此对美国的竞争力也很重要。摩根先进材料将作为GOALI合作伙伴参与，并将为这项研究提供商业和定制设计的碳材料。该项目将为宾夕法尼亚州立大学联邦系统的本科生提供研究机会。该项目的表面分析结果将与研究生教育相结合。将研究两个假设：(I)碳材料的摩擦取决于sp2和sp3杂化的分布以及它们如何连接形成无定形网络，这随合成方法的不同而不同。(Ii)滑动界面上暴露的活性中心的化学活性也因碳材料的合成方式而异。研究这些假设需要分析剪切引起的结构转变和在摩擦界面上发生的化学反应；但该界面并不容易获得，以便进行现场表征。或者，可以从对不同碳材料形成的对接表面上的转移膜的非原位分析中推导出相关信息。这是因为摩擦是一个非平衡过程，转移膜的最终状态将是摩擦过程中初始状态和条件的函数。将使用各种光谱技术来分析转移膜，以确定控制热合成碳材料摩擦磨损行为的摩擦化学参数。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This Grant Opportunity for Academic Liaison with Industry (GOALI) award will support fundamental tribochemistry research that will elucidate the friction and wear behaviors of carbon materials. Carbon blocks and coatings are widely used to control friction and wear of sliding interfaces in manufacturing processes or manufactured goods. This project focuses on understanding and improving tribochemical properties of thermally-synthesized carbon (TSC) materials for the application where low friction is beneficial. Polycrystalline graphite powders and other TSC materials show relatively high friction, although superlubricity is readily observed on the basal plane of graphite and for hydrogenated diamond-like carbon produced via plasma enhanced deposition process. This raises an important question – what controls superlubricous behaviors of different types of carbon materials? Addressing this question can lead to a better design of carbon materials that can be used as carbon brushes for electrical motors or generators and/or mechanical seals in which oil or grease lubrication cannot be employed. Reduction of friction and wear of these components will greatly improve energy efficiency in manufacturing processes. These issues are important in new energy applications and hence US competitiveness. Morgan Advanced Materials is participating as the GOALI partner and will provide commercial and custom-designed carbon materials for the study. The project will provide research opportunities to undergraduate students in the Penn State Commonwealth system. The surface analysis results of this project will be integrated with graduate-level education. Two hypotheses will be studied: (i) Friction of carbon materials depends on the distribution of sp2 and sp3 hybridizations and how they are connected to form the amorphous network, which varies with synthesis method. (ii) The chemical activity of reactive sites exposed at the sliding interface also varies depending on how carbon materials are synthesized. Studying these hypotheses requires the analysis of shear-induced structural transforms and chemical reactions occurring at the frictional interface; but that interface is not readily accessible for in-situ characterization. Alternately, relevant information can be deduced from the ex-situ analysis of the transfer film on the counter-surface formed from different carbon materials. This is because friction is a non-equilibrium process, and the final state of the transfer film will be a function of the initial state and the condition during friction. Various spectroscopic techniques will be employed to analyze the transfer film to identify tribochemical parameters governing friction and wear behaviors of thermally-synthesized carbon materials.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.