Vorselaars Bart, Spencer Russell K W, Matsen Mark W
School of Mathematics and Physics, University of Lincoln, Brayford Pool, Lincoln LN6 7TS, United Kingdom.
Department of Chemical Engineering, Department of Physics & Astronomy, and Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
Phys Rev Lett. 2020 Sep 11;125(11):117801. doi: 10.1103/PhysRevLett.125.117801.
Field theoretic simulations are used to predict the equilibrium phase diagram of symmetric blends of AB diblock copolymer with A- and B-type homopolymers. Experiments generally observe a channel of bicontinuous microemulsion (BμE) separating the ordered lamellar (LAM) phase from coexisting homopolymer-rich (A+B) phases. However, our simulations find that the channel is unstable with respect to macrophase separation, in particular, A+B+BμE coexistence at high T and A+B+LAM coexistence at low T. The preference for three-phase coexistence is attributed to a weak attractive interaction between diblock monolayers.
场论模拟用于预测AB二嵌段共聚物与A类和B类均聚物的对称共混物的平衡相图。实验通常观察到一个双连续微乳液（BμE）通道，该通道将有序层状（LAM）相从共存的富含均聚物的（A+B）相分离出来。然而，我们的模拟发现，该通道相对于宏观相分离是不稳定的，特别是在高温下A+B+BμE共存，在低温下A+B+LAM共存。三相共存的偏好归因于二嵌段单分子层之间的弱吸引相互作用。
