Under normal gravity conditions, buoyancy-driven convection can be caused by the fluid becoming heated due to its electrical resistance as it interacts with electric and magnetic fields. The heating of a material caused by the flow of electric current through it is known as Joule heating. Studies in space may improve techniques for manipulating multiphase systems such as those containing fluid globules and separation processes such as electrophoresis, which uses applied electric fields to separate biological materials. Colloids Colloids are suspensions of finely divided solids or liquids in gaseous or liquid fluids. Colloidal dispersions of liquids in gases are commonly called aerosols.
Smoke is an example of fine solid particles dispersed in gases.
Gels are colloidal mixtures of liquids and solids where the solids have linked together to form a continuous network. Research in microgravity may allow measurement of large scale aggregation or clustering phenomena without the complication of the different sedimentation rates due to size and particle distortion caused by settling and fluid flows that occur under normal gravity. A better understanding of solid-fluid interface dynamics, how the boundary between a solid and a fluid acquires and maintains its shape, can contribute to improved materials processing applications. Such conditions are particularly attractive for testing existing theories for processes and for providing unique data to advance theories for chemical systems where the interface interactions strongly depend on direction and shape.