Dissipative Particle Dynamics Study on Interfacial Properties of Symmetric Ternary Polymeric Blends

We investigated the interfacial properties of symmetric ternary A(n)/A(m)B(m)/B-n and A(n)/A(m/2)B(m)A(m/2)/B-n polymeric blends by means of dissipative particle dynamics (DPD) simulations. We systematically analyzed the effects of composition, chain length, and concentration of the copolymers on the interfacial tensions, interfacial widths, and the structures of each polymer component in the blends. Our simulations show that: (i) the efficiency of the copolymers in reducing the interfacial tension is highly dependent on their compositions. The triblock copolymers are more effective in reducing the interfacial tension compared to that of the diblock copolymers at the same chain length and concentration; (ii) the interfacial tension of the blends increases with increases in the triblock copolymer chain length, which indicates that the triblock copolymers with a shorter chain length exhibit a better performance as the compatibilizers compared to that of their counterparts with longer chain lengths; and (iii) elevating the triblock copolymer concentration can promote copolymer enrichment at the center of the interface, which enlarges the width of the phase interfaces and reduces the interfacial tension. These findings illustrate the correlations between the efficiency of copolymer compatibilizers and their detailed molecular parameters.

Automated summary

The study reveals that the composition of copolymers significantly affects their efficiency in reducing interfacial tension, with triblock copolymers showing higher effectiveness than diblock copolymers. Additionally, shorter chain lengths of triblock copolymers perform better as compatibilizers compared to longer chain lengths, and increasing the concentration of triblock copolymers can promote copolymer enrichment at the interface center, leading to wider phase interfaces and lower interfacial tension.