Development of New Precursors for Lubricious Coatings

抗磨减摩剂是一类发动机油添加剂，用于减少内燃机内部金属-金属接触造成的自身损害，以及用作摩擦改性剂，用于提高发动机效率。二烷基二硫代磷酸锌是用作此类试剂的主要材料之一。然而，尽管它们有效，但它们已知会污染催化转化器-这是一个有问题的问题，导致了寻找替代品的重大研究。虽然运输行业的电气化已经开始，但摩擦学以及抗磨和减摩添加剂的设计和配方在优化每个机械设备的效率方面发挥着重要作用。二烷基二硫代磷酸锌和其他材料如二硫化钼（MoS 2）作为抗磨和润滑材料的广泛使用存在于涉及具有移动机械部件的装置的许多应用中。该博士建议通过研究新的无机材料作为保护涂层，从磨损和摩擦化学的新角度出发，扩大这一研究领域。该项目的目的是合成一系列前体复合物，并评估其在形成减摩薄膜中的潜在应用。目的：现代ICE包含过多的工作部件，这些工作部件涂覆有保护性的抗磨损或减少摩擦的涂层，所述涂层的范围包括SiO2、TiO 2、CrN和金刚石。我们在该项目中的最初重点将是针对特定材料的目标和配方，这些材料通过其已知的应用确定，例如MoS 2或WS 2，这些材料在高温下显示润滑行为已有一段时间。这些材料及其衍生物表现出内在缺陷，这反过来又导致剪切平面的形成。正是这些剪切面在应力下可以促进滑动并有助于这些材料的润滑性质。添加软阳离子如银和钾作为掺杂剂也已显示影响具有所需摩擦系数的材料的形成。遵循一系列预先建立的设计标准，即前体应该是水解稳定的;可溶于高级烃馏分（C8-C20），低毒性;在油中显示热诱导降解;以及最终氧化物材料显示高热稳定性。作为开发任何预期前体的内在因素，研究将涉及以下内容：评估前体及其热屏蔽性能、形成的薄膜组成及其特性;稳定性和溶解度研究;以及例如使用销盘往复装置和超剪切粘度计的机械试验，允许将所形成的薄膜的相关信息反馈到前体设计中。前3个月内的目标包括开发适合于支持包含最终润滑薄膜所需元素的均相体系的配体框架。最初的重点是针对钼和钨硫化物系统的新前体的开发。主管贡献：主要主管（Andrew约翰逊博士）将指导该项目，因为他在薄膜材料沉积和前驱体设计方面具有专业知识。主要主管贡献权重：80%。二级导师（Matt Jones教授）将为该项目提供建议，因为他在配体开发和无机配位化学方面具有专业知识二级导师贡献权重：20%。EPSRC的愿景是推进科学家的知识和技术，以解决几个关键领域，其中之一是气候变化。新型润滑材料的开发有助于减少碳，不仅降低了气候变化的影响，而且保护了当前的环境。

Antiwear and reduced friction agents are a class of engine oil additives used to both reduce self-inflicted damage from metal-metal contact inside internal combustion engines, as well as acting as friction modifiers, which serves to improve engine efficiency. Zinc dialkyl dithiophosphates are one of the leading materials used as such agents. However, despite their effectiveness, they are known to contaminate catalytic converters - a problematic issue which has led to significant research into finding replacements. Although the electrification of the transport industry has already started, tribology and the design and formulation of antiwear and antifriction additives play an important role in the optimisation of efficiency of every mechanical device. Extensive use of zinc dialkyldithiophosphates and other materials such as molybdenum disulphide (MoS2) as antiwear and lubricious materials are present across many applications that involve devices with moving mechanical components. This PhD proposes to expand upon this area of research starting from a new perspective on the topic of wear and tribochemistry by investigating new inorganic materials as protective coatings. The aim of this project is to synthesise a range of precursor complexes and to assess their potential application in the formation of either friction-reduction thin films. Objectives: modern ICEs contain a plethora of working parts coated with protective anti-wear or friction reducing coatings ranging from SiO2, TiO2, CrN and diamond. Our initial focus in this project will be directed toward the targeting and formulation of specific materials identified by their know application such as MoS2 or WS2, which have been known for some time to display lubricious behaviour at high temperatures. These materials and their derivatives exhibit intrinsic defects which in turn results in the formation of Shear planes. It is these Shear planes which under stress, can facilitate sliding and contribute to the lubricious nature of these materials. Addition of soft cations, such as silver and potassium, as dopants has also been shown to affect the formation of materials with desirable friction coefficients. Following a series of pre-established design criteria, i.e. precursors should be hydrolytically stable; soluble in higher hydrocarbon fractions (C8-C20), low toxicity; display a heat induced degradation in oil; as well as the final oxide material displaying a high thermal stability. Intrinsic to the development of any prospective precursor, studies will involve the following: assessment of the precursor and their properties with respect to thermal screening, composition of thin films formed and their characterisation; stability and solubility studies; as well as mechanical trials for example using pin-on-disc reciprocating rigs and ultra-shear viscometers, allowing for relevant information on the thin film formed to be fed back into precursor design. Targets within the first 3 months include development of ligand frameworks suitable for supporting homometallic systems containing which the desired elements for the final lubricious thin film. Initial Focus is directed towards the development of new precursors for molybdenum and tungsten sulphide systems. Supervisor Contributions: The primary supervisor (Dr Andrew Johnson) is to direct the project given his expertise in deposition of thin film materials and in precursor design. Primary supervisor contribution weighting: 80%. The secondary supervisor (Prof Matt Jones) is to advise the project given his expertise in ligand development and inorganic coordination chemistry Secondary supervisor contribution weighting: 20%.The vision of the EPSRC is to advance the knowledge and technology of scientists to tackle several key areas one of which is climate change. The development of novel lubricious materials aids in the reduction of carbon, not only lowering the effefcts of climate change but conserving the current environment.