Development of New Precursors for Lubricious Coatings

抗磨减摩剂是一类内燃机机油添加剂，既可以减少内燃机内部金属-金属接触造成的自身损害，又可以作为摩擦改进剂，提高发动机的效率。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，但众所周知，它们会污染催化转化器--这是一个令人担忧的问题，导致人们对寻找替代品进行了大量研究。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。广泛使用二烷基二硫代磷酸锌和其他材料，如二硫化钼(MoS2)作为抗磨和有色材料，存在于涉及带有移动机械部件的设备的许多应用中。这位博士建议从磨损和摩擦化学主题的新视角出发，通过研究新的无机材料作为保护涂层来扩展这一研究领域。该项目的目的是合成一系列前体络合物，并评估它们在形成减摩薄膜方面的潜在应用。目的：现代冰块包含过多的工作部件，表面涂有从二氧化硅、二氧化钛、氮化铬和金刚石等多种防磨或减摩涂层。我们在这个项目中的最初重点将是针对特定材料的目标和配方，这些材料由其已知的用途识别，如MoS2或WS2，它们在高温下表现出润滑行为已有一段时间。这些材料及其衍生物表现出固有的缺陷，这反过来又导致了剪切面的形成。正是这些剪切面在压力下，可以促进滑动，并有助于这些材料的润滑性。添加软阳离子，如银和钾，作为掺杂剂，也被证明影响具有理想摩擦系数的材料的形成。遵循一系列预先确定的设计标准，即前体应具有水解性稳定性；可溶于较高碳氢化合物组分(C8-C20)，毒性低；在油中表现出热致降解；以及最终的氧化物材料表现出较高的热稳定性。作为开发任何潜在前体的内在条件，研究将涉及以下内容：评估前体及其在热筛选方面的性质、所形成薄膜的成分及其表征；稳定性和溶解性研究；以及机械试验，例如使用销盘式往复式试验机和超剪切粘度计，以便将有关所形成薄膜的相关信息反馈给前体设计。前3个月的目标包括开发适合于支持同金属体系的配位体框架，其中包含最终有色薄膜所需的元素。最初的重点是开发用于硫化钼和硫化钨系统的新前体。主管贡献：鉴于他在薄膜材料沉积和前体设计方面的专业知识，首席主管(安德鲁·约翰逊博士)将指导该项目。主要主管贡献权重：80%。副主管(马特·琼斯教授)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的专业知识。副主管的贡献权重：20%。EPSRC的愿景是促进科学家的知识和技术，以应对几个关键领域，其中之一是气候变化。新型有色材料的开发有助于碳的减少，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.