Publicação
Task-Specific Ionic Liquids and Deep Eutectic Solvents for Lubrication Technology
| Resumo: | It is estimated that around 23% of the world’s total energy consumption comes from tribological contacts, namely due to energy losses during the mechanical movements, which accentuated the need for more efficient lubrication. Lubricants have been used to lower friction and wear by separating the surfaces sliding in relative motion, increasing the energy efficiency and lifetime of mechanical components. It is of extreme importance that the used lubricants comply with the need for higher sustainability and, with that in mind, researchers all over the world are continuously in the search for new and improved ways of reducing friction and wear. Ionic Liquids (ILs) are organic salts with low melting point (generally lower than 100 °C) that have attracted the research community due to their very interesting properties such as high chemical and thermal stability, high ionic conductivity, non-flammability, ease in dissolving organic, inorganic and polymeric materials and their tunability towards several applications through the combination of different cations and anions. Besides that, they have very low vapor pressures which makes them environmentally friendly materials. Ionic Liquids often have good performance in friction and wear reduction, by enhancing the tribofilm formation between different tribopairs, making them very promising alternative lubricants. However, they are very expensive to be used as pure lubricants. Viable alternatives are the use of ionic liquids as additives to a base oil or the use of Deep Eutectic Solvents (DESs), which are mixtures possessing a significant decrease on the melting temperature comparing to the original individual components. DESs have similar properties to ILs but can be less toxic, cheaper and easier to prepare, which makes them very interesting and promising lubricant candidates. In this thesis, the use of different ionic liquids as additives and deep eutectic solvents as lubricants is proposed, with the goal of reducing friction and wear between moving parts, towards a more sustainable world. The most promising fluids can be applied in Nano and Micro electromechanical devices (NEMS/MEMS) which are made of silicon, and also in bearings of steel, which is one of the main materials used in industry. |
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| Autores principais: | Donato, Mariana Trindade de |
| Assunto: | Ionic Liquids Deep Eutectic Solvents Friction Wear MEMS/NEMS |
| Ano: | 2023 |
| País: | Portugal |
| Tipo de documento: | tese de doutoramento |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade Nova de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório Institucional da UNL |
| Resumo: | It is estimated that around 23% of the world’s total energy consumption comes from tribological contacts, namely due to energy losses during the mechanical movements, which accentuated the need for more efficient lubrication. Lubricants have been used to lower friction and wear by separating the surfaces sliding in relative motion, increasing the energy efficiency and lifetime of mechanical components. It is of extreme importance that the used lubricants comply with the need for higher sustainability and, with that in mind, researchers all over the world are continuously in the search for new and improved ways of reducing friction and wear. Ionic Liquids (ILs) are organic salts with low melting point (generally lower than 100 °C) that have attracted the research community due to their very interesting properties such as high chemical and thermal stability, high ionic conductivity, non-flammability, ease in dissolving organic, inorganic and polymeric materials and their tunability towards several applications through the combination of different cations and anions. Besides that, they have very low vapor pressures which makes them environmentally friendly materials. Ionic Liquids often have good performance in friction and wear reduction, by enhancing the tribofilm formation between different tribopairs, making them very promising alternative lubricants. However, they are very expensive to be used as pure lubricants. Viable alternatives are the use of ionic liquids as additives to a base oil or the use of Deep Eutectic Solvents (DESs), which are mixtures possessing a significant decrease on the melting temperature comparing to the original individual components. DESs have similar properties to ILs but can be less toxic, cheaper and easier to prepare, which makes them very interesting and promising lubricant candidates. In this thesis, the use of different ionic liquids as additives and deep eutectic solvents as lubricants is proposed, with the goal of reducing friction and wear between moving parts, towards a more sustainable world. The most promising fluids can be applied in Nano and Micro electromechanical devices (NEMS/MEMS) which are made of silicon, and also in bearings of steel, which is one of the main materials used in industry. |
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