A group of chemists at St Petersburg University conducted research and identified catalysts that, being added to silicone, make it acquire new properties: the material begins to glow in the dark, and its thermal resistance increases up to 320 ° C. The invention of SPbU scientists will help enhance spacecraft thermoregulation systems as well as protect the underwater parts of ships.
The findings of the research have been published in Catalysis Science and Technology, the journal of UK's Royal Society of Chemistry.
Today, silicone materials are used in a variety of areas: from kitchen utensils (for example, baking moulds) to the military industry and aircraft construction. High thermal resistance is one of the most important characteristics of this material. The catalysts invented by the SPbU scientists can significantly improve this property of silicones, that meaning improvement of the quality of any end product.
"At room temperature, the initial silicones tend to be in the liquid state, and adding a catalyst is required to solidify them," said SPbU Assistant Professor Mikhail Kinzhalov, Candidate of Science in Chemistry and project manager at the Russian Foundation for Basic Research in charge of a project aimed at creating new highly efficient catalytic systems. "As a rule, platinum complexes are used for that in industry, but they lead to instant solidification of silicone. To slow down the process, additional substances are needed, but as a result, silicones still end up with relatively low thermal resistance."
To change the situation, we have developed a fundamentally new catalyst composition based on iridium complexes. Now, solidification is not instant. In addition, we were able to increase the thermal resistance of the resulting silicone coating to 320 ° C, which is 120 ° C higher than that of similar silicone materials obtained using the previous catalyst.
SPbU Assistant Professor Mikhail Kinzhalov
SPbU Professor Regina Islamova, Doctor of Science in Chemistry, noted that one more unique feature of the new silicone materials is their luminescence. This property makes it possible to quickly and noncontactly determine the thickness of the silicone coating of the whole object and promptly identify its drawbacks, i. e. areas with a layer of insufficient thickness or completely devoid of coverage. The obtained silicones can, in particular, be used as a basis for special coatings for passive thermoregulation systems of spacecraft.
Silicone coatings are also used as protective layers in the military, medical, automotive, and space industries as well as in many other areas. They effectively protect equipment from various manifestations of moisture (rain, steam, condensate, dampness, salt or chlorinated water), prevent mould formation on the contacts, provide protection against insulation breakdowns and significantly increase the service life of electrical devices.
In addition, using silicone coatings, it is possible to protect the underwater parts of ships from the negative impact of the inhabitants of the aquatic environment. The applied silicone prevents the ship's being fouled by algae and microorganisms and increases the life of imaterial