Directly Experimental Evidence for Melting Process of Solid Domains in Monolayers of Fatty Acids at the Air-water Interface by a Brewster Angle Microscope

First direct observation of the melting processes for fatty acid monolayer at the air-water interface has been successfully made by a Brewster angle microscope. The melting temperatures of solid domains in the monolayers of myristic, palmitic and stearic acids are around 6 °C, 28 °C and 46 °C, respectively. Both the domain size and their distribution become homogeneous when the molten monolayer is cooled down back to the temperature below melting points.