The role of polymer structure on water confinement in poly(N-isopropylacrylamide) dispersions

Poly(N-isopropylacrylamide) (PNIPAM) is a synthetic polymer that widely studied for its thermoresponsive character. However, recent works also reported evidence of low temperature (protein-like) dynamical transition around 225 K in concentrated PNIPAM suspensions, independently the architecture, i.e., both linear chains and microgels. In this work, we investigate water-polymer interactions by extensive differential scanning calorimetry (DSC) measurements systems, order to understand effect different topological structures on solution behaviour, particular regarding crystallization melting processes. addition, compare protiated deuterated microgels, water water. The DSC results are complemented dynamic light scattering experiments, which confirm selective isotopic substitution differently affects behaviour. Our findings highlight important role played architecture behaviour: indeed, microgels turn out be more efficient confining agents, able avoid wider concentration range with respect chains. Altogether, present data will valuable interpret future low-temperature investigations dispersions, particularly neutron experiments.