Competition Between Interfacial Interaction and Microphase Separation in Crystallization of Filled Block Copolymers

Abstract

Understanding the effect of repulsive interaction between blocks on crystallization in block copolymers is beneficial for the design and development of sophisticated nanostructures. Dynamic Monte Carlo simulations were performed to reveal the crystallization mechanism of block copolymers containing onedimensional nanofiller under different repulsive interaction strengths between crystallizable and noncrystallizable blocks. During crystallization, crystalline morphology is determined by the competition between segmental orientation perpendicular to microphase interfaces dominated by microphase separation and that along the direction of the long axis of the nanofiller controlled by interfacial interaction. As the repulsive interaction between different blocks is strengthened, the competition between microphase separation and interfacial interaction is intensified, eventually leading to an increase in crystallization rate and a degradation in crystalline morphology.

Simulations on polymer nanocomposite crystallization

“…Microphase separation can significantly affect the crystallization behaviors of block copolymers filled with nanofillers. It is reported that the enhancement of repulsive interaction between different blocks can promote microphase separation, which in turn leads to the local stretching of crystallizable blocks 99 . Under this condition, the crystallization process through homogeneous nucleation is promoted, as shown in Figure 7A 99 .…”

“…97 Based on molecular simulations, similar structure has also been observed in crystalline-amorphous diblock copolymer systems filled with one-dimensional nanofiller, and the formation mechanism has also been revealed. 98,99 At the beginning of crystallization, due to the attractively interfacial interactions between Microphase separation can significantly affect the crystallization behaviors of block copolymers filled with nanofillers. It is reported that the enhancement of repulsive interaction between different blocks can promote microphase separation, which in turn leads to the local stretching of crystallizable blocks.…”

“…It is reported that the enhancement of repulsive interaction between different blocks can promote microphase separation, which in turn leads to the local stretching of crystallizable blocks. 99 Under this condition, the crystallization process through homogeneous nucleation is promoted, as shown in Figure 7A. 99 In general, the repulsive interaction between the two blocks is the main driving force for microphase separation.…”

“…99 Under this condition, the crystallization process through homogeneous nucleation is promoted, as shown in Figure 7A. 99 In general, the repulsive interaction between the two blocks is the main driving force for microphase separation. In addition, the different crystallizability and the different polymer-filler interactions of various blocks will also promote the occurrence of microphase separation.…”

“…Thus, the final crystal morphology of the system is codetermined by these two factors, as shown in Figure 7B. 99 In the systems with relatively weak repulsive interaction between blocks, the crystallizable segments preferentially crystallize through heterogeneous nucleation, and finally form a regular NHSK structure. In the systems with relatively strong repulsive interaction between blocks, the local stretching of the crystallizable segments is strengthened, and the pre-stretched crystallizable segments preferentially crystallize through homogeneous nucleation.…”