Berlin 2024 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 24: Responsive and Adaptive Systems I

CPP 24.1: Hauptvortrag

Mittwoch, 20. März 2024, 09:30–10:00, H 0110

Thermoresponsive polymers in aqueous environments: insights by atomistic simulations — •Ester Chiessi — Department of Chemical Science and Technologies, University of Rome Tor Vergata, Via della Ricerca Scientifica I, 00133 Rome, Italy

Atomistic molecular dynamics simulations can reproduce the experimentally observed solution behaviour of thermoresponsive polymers in aqueous environments, accessing hydration features, local conformation and dynamics of the macromolecule, as well as solvent properties. This information contributes to clarify the mechanism of the coil-to-globule, C-G, transition and the influence on this process of polymer stereoregularity and presence of cosolvents/cosolutes, as it will be shown for poly(N-isopropylacrylamide), PNIPAM. Then, using PNIPAM as a reference, simulation results on the solution behaviour in water of other amphiphilic polymers will be presented, including a PNIPAM chemical isomer for which the presence of a lower critical solution temperature, LCST, does not imply a C-G transition. The overall picture suggests that the balance between degree of hydrophilicity and conformational aptitudes of the macromolecule determines the occurrence of a thermally-induced coil-to-globule transition and affects the value of the C-G transition temperature in LCST polymer aqueous solutions.

Acknowledgments. The Italian Ministry of University and Research is acknowledged for financial support through the project PRIN 2022PAYLXW Co-MGELS. The CINECA-ISCRA initiative is acknowledged for computing support.

Keywords: thermoresponsiveness; poly(N-isopropylacrylamide); lower critical solution temperature; coil-to-globule transition; molecular dynamics simulation