Evidence of a low-temperature dynamical transition in concentrated microgels.

ABSTRACT: A low-temperature dynamical transition has been reported in several proteins. We provide the first observation of a "protein-like" dynamical transition in nonbiological aqueous environments. To this aim, we exploit the popular colloidal system of poly-N-isopropylacrylamide (PNIPAM) microgels, extending their investigation to unprecedentedly high concentrations. Owing to the heterogeneous architecture of the microgels, water crystallization is avoided in concentrated samples, allowing us to monitor atomic dynamics at low temperatures. By elastic incoherent neutron scattering and molecular dynamics simulations, we find that a dynamical transition occurs at a temperature T _d ~ 250 K, independently from PNIPAM mass fraction. However, the transition is smeared out on ap

SUBMITTER: Zanatta M 

PROVIDER: S-EPMC6162076 | biostudies-literature | 2018 Sep

REPOSITORIES: biostudies-literature