Patent ID: 7155962

Claim:
A method of studying properties of a surfactant, the method comprising the following steps: introducing a first fluid and a second fluid in a measurement chamber and providing the first fluid in a form of a sample volume in the second fluid which is immiscible with the first fluid so that an interface forms between the first fluid and the second fluid at least in a partial area of a surface of the sample volume, the sample volume becoming configured axially symmetrically around a given defining axis so that the interface will be axially symmetrical with respect to the given defining axis; spreading the surfactant across the interface to form a surface film in the area of the interface; and studying the surface film microscopically, wherein said step of studying the surface film includes using a microscope, and aligning an optical axis of the microscope substantially collinearly with the given defining axis; and varying a gas pressure inside a space above the second fluid in the measurement chamber so that a volume of the sample volume is changed.