Liquid-liquid phase separation of polymeric microdomains with tunable inner morphology: Mechanistic insights and applications.

Hypothesis: Liquid-liquid phase separation (LLPS) can provide micron-sized liquid compartments dispersed in an aqueous medium. This phenomenon is increasingly appreciated in natural systems, e.g.

Associative properties of poly(ethylene glycol)-poly(vinyl acetate) comb-like graft copolymers in water.

The self-assembly of amphiphilic graft copolymers is generally reported for polymer melts or polymers deposited onto surfaces, while a small number of cases deal with binary mixtures with water. We report on the associative properties of poly(ethylene glycol)-graft-poly(vinyl acetate) (PEG-g-PVAc) comb-like copolymers in water, demonstrating the existence of a percolative behaviour when increasing the PEG-g-PVAc content. Rheology, light- and small-angle X-ray scattering experiments, together with dissipative particle dynamics simulations, reveal a progressive transition from spherical polymer single-chain nanoparticles (SCNPs) towards hierarchically complex structures as the weight fraction of the polymer in water increases.

Poly(ethylene glycol)-graft-poly(vinyl acetate) single-chain nanoparticles for the encapsulation of small molecules.

Amphiphilic poly(ethylene glycol)-graft-poly(vinyl acetate) copolymers with a low degree of grafting undergo self-folding in water driven by hydrophobic interactions, resulting in single-chain nanoparticles (SCNPs) possessing a hydrodynamic radius of about 10 nm. A temperature scan revealed a lower critical solution temperature (LCST)-type phase behavior. In addition, SAXS data collected close to the LCST showed that these SCNPs aggregate into one-dimensional elongated objects, preferentially.