Magnetic particles stabilized by chemically adsorbed monolayers for use in functional fluids

Chemically adsorbed monolayers were applied to magnetic particle surfaces for preparing functional fluids. Fluorocarbon silanes were used to form the monolayers, as the methoxysilyl groups of fluorocarbon silanes can form a strong chemical bond with the surface of a magnetic particle without degrading its properties. Fluorocarbon oils were used as the carrier liquid because of their high affinity with the fluorocarbon group of the monolayers, enabling the particles to disperse easily in it. Also, fluorocarbon oils can sustain high temperature and low pressure. The functional fluids prepared using these materials showed magnetorheological characteristics and can be used under high-vacuum and/or high-temperature conditions like those encountered in space.