Exploitable results Perfluoropolyethers (oils and surfactants) for ferrofluid preparation and the development of PFPE reaction media for nanosize particle preparation The research aimed at the development of stable colloidal dispersions of magnetic particles in perfluoropolyether (PFPE) oils of Fomblin class, whose physicochemical properties were of interest in advanced sealing technologies. The Consortium activity has lead to the availability of PFPE magnetic fluids with saturation magnetization, viscosity, vapour pressure and durability properties appropriate for sealing applications. The engineering studies have resulted in the prototype of a high precision ferrofluid feedthrough particularly apt to operate in hostile environments due to chemical inertness of the fluorinated components. Several grades of PFPE surfactants have been developed for ferrofluids requirements. Innovative processes for the preparation of nanosize magnetic particles with respect to the state of art for particle preparation in hydrocarbon microemulsions in terms of higher yield and improved control in association with reaction parameters and posttreatment procedures. Two patents have been filed. To develop the application range of such particles beyond ferrofluids, further work is necessary. Magnetic fluid sealing elements A complete sealing system has been developed for the introduction of rotary motion into a vacuum or gaseous atmospheres. The use of magnetic fluid O-rings around a rotating shaft provides an excellent hermetic seal with negligible leakage, no particulate generation, and minimal wear. The main benefits of the technology are: the provision of a non contaminating hermetic sealing with negligible leakage; a seal with extensive life coupled with very high reliability; a sealing system covering a wide speed range with optimum torque transmission at all speeds. To date 3 types of seal have been developed: vacuum seals where motion is to be transferred into a vacuum vessel; exclusion seals where dust or other contaminants are to be prevented from entering a system; hermetic seals where the escape of noxious gases is to be prevented. High performance magnetic fields The project is concerned with the development of ultrastable colloidal dispersions of magnetic particles in perfluoropolyether carrier liquids and of new devices based on these materials. Its aim is to provide the basis for a new class of magnetic fluids taking advantage of chemical inertness, thermal stability, immiscibility and low vapour pressure of the perfluoropolyethers. The research involves the development of surfactants compatible with the carriers and able to stabilise ultrafine magnetic particles. All components are prepared and characterised by the most advanced technologies available to date. An alternative route for the preparation in situ of dispersions is examined. The dispersions are characterized for their physicochemical behaviour and their performance is tested in a sealing device, specifically designed for vacuum technologies. A range of perfluoropolyether (PFPE) magnetic fluids has been obtained and proved to operate in rotary seals without any loss of performance over prolonged and severe tests. 2 types have reached a commercial quality and can be produced in sufficient quantities to allow exploitation. Ferrofluids have been developed on a laboratory scale and their testing is in progress. The PFPE ferrofluids are fully usable in sealing applications, as established over a range of device operating conditions. They outweigh the conventional magnetic fluids in a safety critical environment, while performing similarly to hydrocarbon systems of similar magnetization. The results provide a sound basis for the exploitation plans. Considering all the items developed to date, the perceived advantage over commercially available products mostly relies on a favourable cost to performance ratio. The developed systems and technology are expected shortly to become of commercial interest. Searching for OpenAIRE data... There was an error trying to search data from OpenAIRE No results available
