Mineral oil lubricants protect engine parts from wear, and this effect is enhanced by adding polymer nanoparticles to the lubricating oil. A UK team has now discovered that epoxy functionalization of these nanoparticles further promotes friction reduction on metal surfaces. As the team reports in the journal Angewandte Chemie, nanoparticles containing epoxy groups adhere strongly to stainless steel surfaces, which leads to a significant reduction in friction.
Automotive engines comprising well lubricated parts consume less fuel, produce lower emissions, and suffer less long-term wear. Mineral oil is widely used as a lubricant, and nanoparticles can be directly prepared within this solvent using a technique known as polymerization-induced self-assembly. Coating the surface of the metal components with nanoparticles of a few dozen millionths of a millimeter in size protects them from direct contact.
Csilla György and Steve Armes at the University of Sheffield (UK) designed “hairy” nanoparticles comprising oil-soluble poly(lauryl methacrylate) chains and an oil-insoluble nanoparticulate core. These nanoparticles were made to stick strongly to metal surfaces by introducing epoxy groups into the “hairs” by copolymerizing lauryl methacrylate with glycidyl methacrylate, an epoxy-functional monomer.
The team found that the epoxy-bearing nanoparticles reacted with hydroxy groups located at the surface of stainless steel. This reaction led to strong adhesion of the nanoparticles, a phenomenon known as chemical adsorption. Whether chemical adsorption occurred or not depended on the precise location of the epoxy groups. “To our surprise, introducing a far larger number of epoxy groups into the nanoparticle cores had no beneficial effect,” explains Armes.
The adsorbed nanoparticles reduced friction significantly, as the Sheffield team discovered when conducting tribological studies in collaboration with scientists at Lubrizol, an engine oil additives company based in the UK. “Remarkably, the adsorbed nanoparticles remained intact on the stainless steel surface after such experiments, which were conducted at the typical operating temperature of an internal combustion engine,” Armes adds.
Such epoxy-functionalized nanoparticles could therefore mean a further leap in performance for lubricant additives for next-generation engine oil formulations.
Making Drinking Water Bacteria-Free
Water contaminated with bacteria is a large threat to global health. A Chinese research team has described a simple new method of disinfection in the journal Angewandte Chemie. It is based on tiny biocompatible assemblies of atoms, known as quantum dots, made of silver sulfide with caps mad ... more
Huge amounts of technical or Kraft lignin are formed during pulp production. This lignin is difficult to process and so is usually just incinerated for heat production. A team of researchers, reporting in the journal Angewandte Chemie, have now succeeded in developing a green method for rec ... more
Until now, it has been clear: you can have a metal or a plastic, but not both in one. However, things don’t have to stay that way. In the journal Angewandte Chemie, a Chinese research team has now reported a polymer with a metallic backbone that is conductive, thermally stable, and has inte ... more
Nouryon announces 2019 Imagine Chemistry finalists
Nouryon (formerly AkzoNobel Specialty Chemicals) has announced the 13 finalists for the 2019 edition of its Imagine Chemistry collaborative innovation challenge. Imagine Chemistry was launched to tackle chemistry-related challenges and uncover new ways to create value for customers. The 201 ... more
1 + 1 does not equal 2 for graphene-like 2D materials
Physicists from the University of Sheffield have discovered that when two atomically thin graphene-like materials are placed on top of each other their properties change, and a material with novel hybrid properties emerges, paving the way for design of new materials and nano-devices. This h ... more
Fibers from old tires can improve fire resistance of concrete
A new way of protecting concrete from fire damage using materials recycled from old tyres has been successfully tested by researchers at the University of Sheffield. The team used fibres extracted from the textile reinforcement commonly embedded into tyres to guarantee their performance. Ad ... more
