Investigation of magnet polarity induced ferrofluid ring pattern in microgravity and hypergravity

The formation of spike in ferrofluid is usually influenced by several factors, which includes interaction of the surface energy, gravitational force, retention force, surface tension and also the size and the type of magnetic nanoparticles dispersed in the storing medium. In this paper, the changes of the first ring pattern of ferrofluid are observed under microgravity and hypergravity conditions stimulated by parabolic flight. Among the parameters manipulated includes the dispersion medium (water-based/oil-based) of ferrofluid, the volume of ferrofluid, and the polarity of the magnet. The water-based ferrofluid (W40) is more likely to alter the shapes of ring pattern compared to the oil-based ferrofluid (P50) under different gravity conditions. Small volume of ferrofluid (0.1ml) gives more variation in terms of ring pattern compared to the large volume of ferrofluid (0.5ml). The ring pattern induced by the North pole and the South pole of magnet are compared.