Effect of Hofmeister Ions on the Size and Encapsulation Stability of Polymer Nanogels

Abstract

Influence of Hofmeister ions has been investigated on the size and guest encapsulation stability of a polymeric nanogel. While variations in macroscopic phase transitions have been observed in response to the presence of salts, changes in the size and host-guest behavior of polymeric aggregates in the presence of salts have not been explored in any detail. We find that the size and core density of nanogel, which was prepared by self-crosslinking from a random copolymer that contains oligo(ethylene glycol) (OEG) and pyridyl disulfide (PDS) units as side-chain functionalities, can be fine-tuned through the addition of both chaotropes and kosmotropes during nanogel formation. We also demonstrate that the change in core density affects the guest encapsulation stability and stimuli-responsive character of the nanogel.