New sol-gel coatings fight corrosion and improve environmental friendliness
Researchers from Sheffield Hallam University’s Materials and Engineering Research Institute are developing a range of advanced sol-gel coatings – to be used on various aspects, including environmentally friendly anticorrosion coatings for aerospace light alloys, functionalised coatings (eg coloured coatings, anti-icing coatings, and lightning strike protection coatings) for aerospace and automotive polymer-carbon fibre composites, antibiotic coatings for medical devices, solid or quasi-solid electrolytes for the enhancement of safety in energy storage of batteries and supercapacitors, low-temperature-processed robust and transparent conductive coatings for electronic devices and solar cells, etc.
Sol-gel coatings are produced by creating or dispersing organic, inorganic, or organic-inorganic hybrid nanoparticles within a liquid (termed the ‘sol’), allowing the sol to condense, producing a ‘gel’, which on application to a surface and heating (curing) produces a solid and dense film with various designated properties.
Unfortunately, traditional sol-gel systems, which mainly utilise chemistry/formulation and excessively high cure temperatures to obtain inorganic coatings, often have limited coating thickness (typically less than a micron). However, research being undertaken by Dr Heming Wang is presently aiming to combine the benefits of inorganic and organic components to form various new hybrid structures that provide specific coating properties such as corrosion resistance, electrical conductivity, biological functionality, and thermal stability, along with mechanical toughness and flexibility. This new approach will also allow for thicker coatings to be applied, with requirements of various curing conditions.
Dr Wang’s team are also investigating the potential to combine their innovative coatings with manufacturing processes to produce cost-effective end products and are developing novel light absorber for solution-processed solar cells, wherein a photoactive polymer and a halide perovskite are blended to deliver wide light absorption and stability enhancement (patent pending). The Materials and Engineering Research Institute has a long history of developing coatings and functional materials, and Dr Wang’s team has recently worked on a range of funded projects by the Innovate UK and/or ATI, MoD, involving in the £30 million VIEWS project (Validation and Integration of Manufacturing Enablers for Future Wing Structures) led by GKN with 13 partners.
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