Diblock Copolymer Grafted Particles as Compatibilizers for Immiscible Binary Homopolymer Blends

Using coarse-grained molecular simulations we study AB diblock copolymer grafted particles (DBCGPs) as compatibilizers in an immiscible blend of A and B homopolymers. The fraction of the A block in the graft, f A, tunes the location of the DBCGPs within the blend. When f A = 0.25, the DBCGPs preferentially localize in the B domain of the blend, and when f A = 0.5 and 0.75, the DBCGPs localize at/near the interface of the A and B domains, adopting conformations that segregate the A and B segments of the grafts into chemically identical domains of the blend. The desorption energy to leave the interface and the drop in interfacial tension are larger for the DBCGP than ungrafted diblock copolymers, commonly used as compatibilizers. Additionally, the comparable reduction in interfacial tension of DBCGPs as Janus-homopolymer grafted particles, along with the easier synthesis routes of DBCGP, makes DBCGP an attractive alternative class of compatibilizers for polymer blends.