Computer design of copolymers with desired functionalities: Microphase separation in diblock copolymers with amphiphilic block

Using the mesoscale simulation techniques, self-consistent field (SCF) method and dissipative particle dynamics (DPD), we study microphase separation in the melt of amphiphilic/nonpolar diblock copolymers. It is shown that the phase diagram for the melt of diblock copolymers with an amphiphilic block can be significantly different from that known for the conventional model of a diblock copolymer. In particular, we find that longer nonpolar blocks may be assembled in micelles separated by a matrix of shorter amphiphilic blocks. The physical reason behind this is connected with the surface activity of amphiphilic; monomer units, which forces them to be located in the regions of maximum concentration gradient. In the limit of significant amphiphilicity (surface activity), the resulting morphology corresponds to thin channels and slits of amphiphilic units penetrating through the matrix of a major nonpolar component.