  The phase behavior of asymmetrically interacting ABC star triblock copolymer
melts is investigated by the self-consistent field theory (SCFT). Motivated by
the experimental systems, in this study, we focus on the systems in which the
Flory-Huggins interaction parameters satisfy $\chi_{AC}>\chi_{BC}\approx
\chi_{AB}$. Using various initialization strategies, a large number of periodic
structures have been obtained in our calculations. A fourth-order
pseudospectral algorithm combined with Anderson mixing method is used to
compute the free energy of candidate structures carefully. The stability has
been detailedly analyzed by splitting the free energy into internal and
entropic parts. A complete and complex triangular phase diagram is presented
for a model with $\chi_{AC}>\chi_{BC}= \chi_{AB}$ in which fifteen ordered
phases, including two-, and three-dimensional structures, have been predicted
to be stable from the SCFT calculations. Generally speaking, with the
asymmetrical interactions, the hierarchical structures tend to be formed near
the B-rich corner of the triangular phase diagram. This work broadens the
previous theoretical results from equal interaction systems to unequal
interaction systems. The predicted phase behavior is in good agreement with
experimental observations and previous theoretical results.
