Ultrasonic study of thermo-acoustic parameters of the polysorbate 20, 40, 60 and 80 liquid surfactants at different temperatures

The above figures represent the variation of isentropic compressibility and intermolecular free length at different temperatures and samples. The variation in them shows that the number of hydro-carbon atoms in hydrophilic/lyophilic and hydrophobic/lyophobic parts of the molecules, their chain length and their temperature, control their physico-chemical properties.