Mechanics versus Thermodynamics: Swelling in Multiple‐Temperature‐Sensitive Core–Shell Microgels

Abstract

The thermal transition of a thermoresponsive microgel of poly-N-isopropylacrylamide (PNIPAM; transition temperature=34 °C) is shifted to higher temperatures when it is embedded in a shell of temperature-sensitive poly-N-isopropylmethacrylamide (PNIPMAM; transition temperature=44 °C). The magnitude of the shift depends on the shell/core mass ratio. A thick shell induces a third transition arising from strong mechanical forces exerted on the core.