Periodic Patchy Spheres Self-Assembled by A m BCA n ' Multiblock Terpolymers.

We have designed A m BCA n ' multiblock terpolymers and studied their self-assembly using self-consistent field theory, aiming to generate the periodically arranged patchy spheres and thus to clarify the regulation mechanism of the number of patches. A number of two-dimensional phase diagrams are constructed for three typical architectures A 2 BCA 2 ' , A 2 BCA 3 ' , and A 3 BCA 2 ' . Four kinds of stable patchy spheres with the number of patches as 2 (S 2 ), 4 (S 4 ), 5 (S 5 ), and 6 (S 6 ) are obtained. These phases follow a common transition sequence of S 2 → S 4 → S 5 → S 6 along with the increasing of the volume fraction of C-block ( f C ), which forms the core sphere patched with B-domains. Moreover, the S 6 phase exhibits the widest stability window, while S 5 has the narrowest one. The increased arms of A'-blocks in A 2 BCA 3 ' architecture deflect the phase boundaries toward large f C and accordingly expand the regions of these patchy spheres due to the amplified effect of spontaneous curvature. In contrast, the increased arms of A-blocks in A 3 BCA 2 ' remarkably expands the window of S 6 but narrows those of the other patchy spheres, which is mainly caused by increased packing frustration resulting from the reduced extension of the more divided A-blocks. The widest window of the S 6 phase reaches Δ f C ∼ 0.13, which is readily accessed by experiment. Our work not only demonstrates a self-assembly strategy to engineer the patchy spheres, but also sheds light on the regulation mechanism of the patchy number.