Surfactants are known to affect evaporation performance of solutions. They are studied in relation to water loss prevention. In previous studies, evaporation suppressants have been effective in the laboratory and at small scales such as on swimming pools, ponds, and small lakes. Surfactants could be useful under drought conditions in arid areas of the world. Previous researchers conducted tests to estimate the spreading and coverage efficiencies of evaporation suppressants. Effectiveness of the suppressants in reducing evaporation is evaluated. Monolayers are one molecule thick films that form at a phase boundary such as the air-water interface. The optimal methods of spreading and reapplication of monolayers need to be determined. Hydrotopes are organic salt compounds and they improve the ability of water to dissolve other molecules. Hydrotropy is one of the solubility enhancement techniques which enhance solubility with use of hydrotropes.
The purpose of the research is to measure the viscosity and natural evaporation of selected aqueous surfactant and hydrotope solutions. The viscosity of the aqueous-surfactant solutions at various concentrations are measured with falling-ball viscometer. The surfactants are shown to increase viscosity when added to distilled water. Some surfactants and hyrotopes reduced natural convection water loss over five days showing an effect on evaporation rates.