Polyethylene Glycol (PEG)-based hydrogels are valued for their biocompatibility and cost-effectiveness, yet achieving specific structures remains challenging.
In this study, we report a novel PEG-based nanogel system synthesized via conventional free radical polymerization under oxygen-rich conditions. During which diverse functional groups—such as peroxides and carboxylic acids—were introduced into the network. The Nanogels undergo pH-responsive swelling at physiological pH (7.4) due to carboxylic acid groups. This swelling behavior triggers a jamming transition at high concentrations. Additionally, the presence of peracid groups facilitates a secondary gelation process at body temperature. At high particle concentration, the Nanogel dispersion maintains low viscosity. These properties highlight the potential of this system as an injectable, pH-responsive hydrogel platform with controllable in situ solidification behavior.