GOALI: Enabling Ultra-Low Viscosity Lubricants Through Fundamental Understanding of Additive Interactions and Tribofilm Growth Mechanisms: An In-Situ Study

GOALI：通过对添加剂相互作用和摩擦膜生长机制的基本了解，实现超低粘度润滑剂：原位研究

基本信息

批准号：
1728360
负责人：
Robert Carpick
金额：
$ 38.38万
依托单位：
University of Pennsylvania
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-09-01 至 2021-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1728360&HistoricalAwards=false
关键词：
GOALI Enabling Ultra Low Viscosity

项目摘要

Automobile engine oils typically include several different performance additives, each of which serves a crucial role in improving fuel efficiency and engine reliability. One of the additive types that are routinely added to such lubricants are anti-wear additives, which are required to reduce wear and failure when metal-on-metal contact occurs between the various parts within automobile engines. One such additive, a molecule based on a combination of zinc, sulfur, phosphorous, oxygen, and hydrocarbons, is so effective at reducing wear while being inexpensive to produce that it is used in nearly every automotive engine oil. This molecule works by forming surface films at certain contact points within the engine. These films serve as a protective cushion for the underlying metal parts, protecting them from wear. Despite its widespread use, it remains unclear how this molecule generates these protective films. Increasingly, automotive lubricants are being formulated with lower viscosities which help improve fuel economy and reduce undesirable emissions. Unfortunately, the molecules used to formulate these lower viscosity oils can interfere with the anti-wear molecule?s ability to generate protective films and provide adequate wear protection. This Grant Opportunities for Academic Liaison with Industry (GOALI) research aims to contribute to solving this problem by using novel nanotechnology methods to improve our understanding of how the anti-wear protective films are formed and how their formation is affected by interactions with other types of additives. Findings of this research will inform the design of next-generation automotive lubricants and will thus have a direct impact on the U.S. economy through improved energy saving, reductions in maintenance-related costs, and reduction of undesirable emissions.In this research, a quantitative kinetic and thermodynamic understanding of anti-wear tribofilm formation mechanisms will be formulated using novel in-situ atomic force microscopy methods, recently developed at UPenn. In-situ atomic force microscopy enables the direct probe of nanoscale mechanochemistry of zinc dialkyldithiophosphate additives (known as ZDDP-based additives) which drives formation of tribofilms, as well as their interactions with novel basestock and co-additives including molybdenum-based friction modifiers and dispersants. Synergism or antagonism between anti-wear additives and co-additive chemistries will be identified and understood through measurement and interpretation of tribofilm growth kinetics. Together with ex-situ chemical and structural characterization techniques at UPenn, as well as lubricant expertise and component-scale testing at ExxonMobil, this research will help enable predictive design, development, and implementation of advanced formulations for next-generation lubricants. By identifying how co-additives affect the fundamental mechanisms of tribofilm growth, this research will in the longer-term help identify sulfur and phosphorous-free anti-wear additives. Sulfur and phosphorous are known to have deleterious impacts on automotive emissions, and thus developing alternatives to ZDDP additives is crucial for further reducing automotive emissions.

汽车发动机油通常包含几种不同的性能添加剂，每种添加剂在提高燃油效率和发动机可靠性方面都发挥着至关重要的作用。通常添加到此类润滑剂中的添加剂类型之一是抗磨损添加剂，当汽车发动机内的各个部件之间发生金属与金属接触时，需要使用抗磨损添加剂来减少磨损和故障。其中一种添加剂是一种基于锌、硫、磷、氧和碳氢化合物组合的分子，它在减少磨损方面非常有效，而且生产成本低廉，几乎用于所有汽车发动机油中。该分子的工作原理是在发动机内的某些接触点形成表面薄膜。这些薄膜充当底层金属部件的保护垫，保护它们免受磨损。尽管其广泛使用，但仍不清楚该分子如何产生这些保护膜。汽车润滑油越来越多地采用较低粘度配制，这有助于提高燃油经济性并减少不良排放。不幸的是，用于配制这些较低粘度油的分子会干扰抗磨分子生成保护膜并提供足够的磨损保护的能力。这项学术与工业联络的资助机会（GOALI）研究旨在通过使用新颖的纳米技术方法来帮助解决这个问题，以提高我们对抗磨保护膜如何形成以及它们的形成如何受到与其他类型的相互作用的影响的理解。添加剂。这项研究的结果将为下一代汽车润滑油的设计提供信息，从而通过改善节能、降低维护相关成本和减少不良排放，对美国经济产生直接影响。在这项研究中，定量动力学将使用宾夕法尼亚大学最近开发的新型原位原子力显微镜方法来制定对抗磨损摩擦膜形成机制的热力学理解。原位原子力显微镜能够直接探测二烷基二硫代磷酸锌添加剂（称为 ZDDP 基添加剂）的纳米级机械化学，该添加剂可促进摩擦膜的形成，以及它们与新型基料和辅助添加剂（包括钼基摩擦改进剂和添加剂）的相互作用。分散剂。通过测量和解释摩擦膜生长动力学，可以识别和理解抗磨添加剂和共添加剂化学物质之间的协同或拮抗作用。与宾夕法尼亚大学的异位化学和结构表征技术以及埃克森美孚的润滑油专业知识和组件规模测试相结合，这项研究将有助于实现下一代润滑油先进配方的预测设计、开发和实施。通过确定辅助添加剂如何影响摩擦膜生长的基本机制，这项研究从长远来看将有助于识别无硫和无磷的抗磨添加剂。众所周知，硫和磷会对汽车排放产生有害影响，因此开发 ZDDP 添加剂的替代品对于进一步减少汽车排放至关重要。