Expanding the window of the Frank-Kasper σ phase of block copolymer/homopolymer blend by selective incorporation of metal salt

Unlocking the Frank-Kasper phase in block copolymers represents a significant breakthrough, shedding light on the fundamental principles governing versatile particle arrangements across various size scales. Nevertheless, achieving this intricate phase is a challenging task that demands precise control of factors such as molecular weight, molecular architecture, and conformational asymmetry. Furthermore, the compositional window for this intricate packing is quite narrow. This study contributes a facile method for expanding the window of Frank-Kasper \ensuremath{\sigma} phase. By introducing a minute quantity of metal salt into the core of the micelle, the compositional and thermal windows of the Frank-Kasper phase is broadened significantly due to the collective effects of core enlargement and shift of the spherical phase boundary to higher core volume fraction.