Disorder to Order Transition and Ordered Morphology of Coil-Comb Block Copolymer by Self-Consistent Field Theory.

Zhibin Jiang,Zhiyuan Qian,Hong Yang,Rong Wang

doi:10.1186/s11671-015-1035-8

Abstract

The disorder to order transition and the ordered patterns near the disordered state of coil-comb copolymer A-b-(Bm + 1-g-Cm) are investigated by the self-consistent field theory. The phase diagrams of coil-comb copolymer are obtained by varying the composition of the copolymer with the side chain number m = 1, 2, and 3. The disorder to order transition is far more complex compared with the comb copolymer or linear block copolymer. As the side chain number m increases, the Flory-Huggins interaction parameter of disorder to order transition (DOT) increases and the lowest DOT occurs when the volume fractions of blocks A, B, and C are approximately equal. When one component is the minority, the disorder to order transition curve is similar with binary copolymer, but the curve shows the asymmetric property. The comb copolymer is more stable with larger side chain number m and shorter side chain. The ordered patterns from the disordered state are discussed. The results are helpful for designing coil-comb copolymers and obtaining the ordered morphology.

Highlights

The ability of block copolymers to spontaneously form microphase-separated structures with length scales of 10–100 nm makes them extensive applications in nanoscience, such as pore materials [1], drug delivery [2], and templates [3, 4]
By systematically varying the volume fractions of the three blocks and the Flory-Huggins parameter χN, we got the phase diagrams of the disorder to order transition for the coil-comb copolymer, which are shown in Fig. 2, and parts a, b, and c are referred to the situations of m = 1, 2, and 3, respectively
We can find that the disorder to order transition (DOT) parameter χN is larger at the corners of the three blocks, and the χN of DOT is lower when the volume fractions of the three blocks are approximately comparable

Summary

Introduction

The ability of block copolymers to spontaneously form microphase-separated structures with length scales of 10–100 nm makes them extensive applications in nanoscience, such as pore materials [1], drug delivery [2], and templates [3, 4]. Researchers are devoted to design block copolymers with different architectures to engineer functional materials. The Frank-Kasper σ phase can form in two different single-component, sphereforming, block copolymer melts near the order-disorder transition temperature (TODT) [6, 7]. Xie et al [8] studied asymmetric miktoarm block copolymers which can self-assemble into fcc, bcc, A15, and the complex σ phase. They even designed multiblock terpolymers which can self-assemble into various binary mesocrystals with space group symmetries of a large number of

Methods

Results

Conclusion