| Abstract: | The stabilizing (emulsifying) effect of a symmetric diblock copolymer in the mixture of two immiscible homopolymers is considered. The equilibrium value of the interfacial area per copolymer chain is calculated via minimization of the free energy of the mixture for a fixed number of copolymer chains adsorbed to the interface. The size and concentration of droplets of the minor component are determined for the equilibrium state. The particles' radius is shown to be inversely proportional to the copolymer concentration, the coefficient of proportionality being dependent on the Flory-Huggins parameter and chain length. The penetration of homopolymer segments into the copolymer layer on the interface is taken into account and proved to be important for stabilization of the droplets by symmetric copolymers. The conditions of the validity of the presented approach are discussed in detail. |
