Surface tension for physical chemistry testing
Water solubility is a basic physical chemical parameter of a substance, and physical chemistry is fundamental to the development and subsequent approval of a crop or chemical active substance. Surfactants, or surface-active agents, are designed to reduce the surface tension of liquids to allow better mixing of phases or increased wetting. In this test, as increasing concentrations of surfactant are added to water, the surface tension decreases until the minimum surface tension is reached. Simple dilutions of a strong, fully dispersed stock solution of test substance are used and the surface tension of each dilution is measured.