Simulation of the adsorption of unsymmetric diblock copolymers at the interface between the two monomeric homopolymers


An unsymmetric diblock copolymer has been suggested to be more effective than a symmetric diblock copolymer for compatibilization of a blend of two homopolymers. It reduces the formation of the micelle which competes with the preferred adsorption of the diblock at the interface of the two homopolymer fields. The homopolymer fields used in the simulations are monomeric homopolymer fields. The composition of the chains is changed from symmetric to unsymmetric, and the equilibrium adsorption of the chains at the interface between the two monomeric homopolymer fields is studied as a function of the composition of the chains and the interaction energy. The new results obtained with unsymmetric diblock copolymers can be described by the same functional dependence that we have previously obtained [Y. Wang and W. L. Mattice, J. Chem. Phys. 98, 9881 (1993)] for the symmetric diblock copolymer, as long as the proper replacement of variable is made. In addition, the equilibrium of unsymmetric diblock copolymers in the two different monomeric homopolymer fields enables us to test the validity of Flory-Huggins theory of the thermodynamics of polymer mixing with the solvent. No major deviation from the Flory-Huggins theory has been observed. © 1993 American Institute of Physics.

Publication Title

The Journal of Chemical Physics