ATRP Enhances Structural Correlations In Polymerization‐Induced Phase Separation**

Abstract

Synthetic methods to control the structure of materials at sub-micron scales are typically based on the self-assembly of structural building blocks with precise size and morphology. On the other hand, many living systems can generate structure across a broad range of length scales in one step directly from macromolecules, using phase separation. Here, we introduce and control structure at the nano-and microscales through polymerization in the solid state, which has the unusual capability of both triggering and arresting phase separation. In particular, we show that atom transfer radical polymerization (ATRP) enables control of nucleation, growth, and stabilization of phase-separated poly-methylmethacrylate (PMMA) domains in a solid polystyrene (PS) matrix. ATRP yields durable nanostructures with low size dispersity and high degrees of structural correlations. Furthermore, we demonstrate that the length scale of these materials is controlled by the synthesis parameters.

Statistical Copolymerization-Induced Self-Assembly

“…The observed increase in micellar size with polymer concentration in stat -PISA can be rationalized by the coarsening of the phase-separated structure after spinodal decomposition and the nonelastic collision of the micelles. A similar dependence was also observed in a polymerization-induced phase separation system based on atom-transfer radical polymerization and a solid-state polymerization-induced phase separation system …”

“…The observed increase in micellar size with polymer concentration in stat-PISA can be rationalized by the coarsening of the phase-separated structure after spinodal decomposition and the nonelastic collision of the micelles. A similar dependence was also observed in a polymerizationinduced phase separation system based on atom-transfer radical polymerization 42 and a solid-state polymerizationinduced phase separation system. 43 The broad monomer library of stat-PISA was demonstrated by the preparation of statistical copolymer assemblies with varying chemical compositions and surface charges (Figures S13−S18 and Table S4).…”

Photoclick Phase-separating Hydrogels for 3D Cell Culture and Volumetric Bioprinting

“…Phase separation in living systems relies on macromolecules. Unlike small molecules, macromolecules tend to separate and form droplets in aqueous solutions when the mixing entropy is not favourable due to large molar mass 24,25 .…”

“…Phase separation in living systems relies on macromolecules. Unlike small molecules, macromolecules tend to separate and form droplets in aqueous solutions when the mixing entropy is not favourable due to large molar mass 24,25 . Herein, we report fast construction of cell-compatible macroporous hydrogels by leveraging a thiol-ene photoclick resin 16,26 and photopolymerization-induced phase separation (PIPS, Fig.…”