This discussion centers on achieving a 'heat wave' visual effect using glycerin and various solvents. Initial attempts with water and 95% ethyl alcohol resulted in complete mixing, eliminating the desired effect. Participants suggest alternatives such as hexane, kerosene, and silicone oil, emphasizing the need for immiscible liquids to maintain the visual gradient. The consensus is that while glycerin alone is ineffective, combinations with hydrocarbons like butane or silicone oil may yield the desired results without mixing.
PREREQUISITESThis discussion is beneficial for filmmakers, visual artists, and chemists interested in creating unique visual effects using liquid combinations. It provides insights into practical applications of chemistry in art and safety considerations when working with volatile substances.
Nemus said:I have noticedthat somewhat surprisinlgly you can see these refractive index whorls in concentrated solutions of polyethyleneglycol solutions. Even old ones in sealed flasks that should be homogenous. My theory is that the selective accumulation of water vapor in the headspace is enough to cause some swirls. High Mw polyethyleneglycol can be bought as a laxative under various brand names. I think the generic name is macrogol.
Liquids that are imiscilble will not give the effect. However, you can get something like it if you match the density of two imiscible liquids. Water + dichloromethane (or even more toxic chloroform) + heptane (less toxic than hexane) would work. Silicone oil + a strong salt solution (sodium chloride may not be soluble enough so CaCl2 may have to be used)may also be an alternative but then I am only guessing.