Tuning polymer architecture for quasicrystal self-assembly

TL;DR

This study uses simulations and theory to show how tuning polymer architecture in dendrimers can control ultrasoft interactions, leading to stable quasicrystal formation, guiding experimental design of soft matter quasicrystals.

Contribution

It introduces a model linking dendrimer architecture to mesoscopic phase behavior, enabling targeted design of quasicrystals in soft matter systems.

Findings

Stable dodecagonal quasicrystals can be achieved by specific polymer architectures.

The phase stability region for quasicrystals is tunable through molecular design.

A simple pair potential model accurately predicts phase behavior.

Abstract

Using computer simulations and theory, we investigate the ultrasoft interactions between dendrimers formed of a central polymer connected by stiff linkers to a corona of flexible polymers, forming `pompoms' at the ends of the linkers. We show that the resulting coarse-grained interaction potential between pairs of dendrimers exhibits tunable lengthscale competition based on properties of the core and corona polymers. We present a simple model for this pair potential, which we confirm using accelerated Monte Carlo methods. We then demonstrate the connection between dendrimer structure and mesoscopic phases by presenting parameter choices that result in stable dodecagonal quasicrystals, and show that the size of the region in the phase diagram where quasicrystals are stable can be controlled by tuning details of the polymer architecture alone. These results pave the way for experimental realization of soft matter quasicrystals by identifying what overall molecular architecture leads to their stability.