Exofluid
An exofluid is an exophysical substance capable of inducing either entropic or syntropic effects into particles they come into contact with. Exofluids can be used to achieve an extremely high rate of thermal conductivity, with near-perfect efficiency; in the modern era, they are often used in the cooling systems of singularity reactors and bridge generators. They were also used in the system of Vertex frames due to their immense thermal density.
Red acid is an example of an entropic exofluid, while QFluid is syntropic. Mass corresponds to the charge; i.e. an entropic exofluid has a positive mass and obeys normal gravity, while a syntropic exofluid is inverted. The fluid is "expendable" and must be regenerated to be used in a closed-loop system, usually done with machines known as acid mixers.
History
Entropic exofluids were first discovered by Nevrin in the 1960s while developing initial prototypes of the Cavity Reactor, creating red acid. Their syntropic counterparts were not conceived until much later in the 21st Century, when CERN discovered the syntropic plane and Voima Tech Industries subsequently developed QFluid.
Production
Exofluids are produced at specialist cavity reactor facilities designed for fluid irradiation purposes. They can be produced using a variety of base liquids; such as water, ammonia, and molten sodium. The irradiation of hydrazine produces hyporine, a highly volatile high-density fuel for sublight spacecraft.