William Griffin and J. T. Davies  devised measurements of the hydrophilic-lipophilic balance of these substances, based on the fact  that molecules of these chemicals have soluble and insoluble ends.
Molecules can only be used effectively for this purpose when they are above their Krafft temperature,   and low concentrations of these form a layer named for Irving Langmuir and Katharine Blodgett.  These substances are often added to fluids flowing through pipes to prevent corrosion, and they are  added to windows and lenses to prevent them from fogging up. William Griffin and J. T. Davies  devised measurements of the hydrophilic-lipophilic balance of these substances, based on the fact  that molecules of these chemicals have soluble and insoluble ends. Name these chemicals, used in  soaps, which lower surface tension.
Molecules can only be used effectively for this purpose when they are above their Krafft temperature,   and low concentrations of these form a layer named for Irving Langmuir and Katharine Blodgett.  
surfactants [or surface-active agents or surface-acting agents]