All-Aqueous Multi-Phase Systems And Emulsions Formed Via Low-Concentration Ultra-High-Molar Mass Polyacrylamides

Aqueous multi-phase systems have attracted a broad interest in recent years, which is mainly due to their applicability in biology for purification and isolation of biomolecules and also for separation of particles as well as environment for enzymatic reactions. Here, three polyacrylamides poly(N,N-dimethylacrylamide), poly(acrylamide), and poly(4-acryloylmorpholine) with ultra-high molar mass were synthesized via photo-induced reversible addition-fragmentation chain-transfer polymerization (M-n > 700,000 g.mol(-1)). The polymers were combined to form aqueous multi-phase systems with low total polymer concentration as low as 1.1 to 2.1 wt %. Furthermore, the aqueous multi-phase system could be transformed into water-in-water (w/w) emulsions, stabilized by layered double hydroxide nanoparticles. Due to the low polymer content, these aqueous multi-phase systems open up new pathways, for example, in the separation of biomolecules or the compartmentalization of aqueous environments in catalysis.