Molecular Parameters Favoring Disordered Hyperuniformity in Brush Particle Materials

Abstract

The concurrence of “single crystal-like” uniformity and isotropy of structure and properties is expected to endow disordered hyperuniform (DH) materials with novel property combinations that have fueled interest in DH hybrid materials as a platform for functional material design. For the example of poly(methyl acrylate) (PMA)-tethered silica (SiO2) particles, this work explored the role of brush architecture and linear polymer (PMA) addition on the degree of hyperuniformity of brush particle assembly structures in the bulk and thin-film states. The results reveal that brush “softness” is a critical design parameter for synthesizing brush particle materials that can be reliably processed into disordered hybrid materials. Here, “softness” refers to shallower interaction potentials achieved, for example, by increasing the degree of polymerization or decreasing the grafting density of tethered chains. Interestingly, in the bulk state, the addition of PMA was required to reduce long-wavelength fluctuations below those of a regular liquid reference state. This suggests that blending of ‘soft’ brush particles with isomorphous linear polymers could present a path for the deliberate fabrication of DH hybrid materials.