Berlin 2018 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 63: Polymer and Molecular Dynamics II

CPP 63.13: Vortrag

Donnerstag, 15. März 2018, 12:45–13:00, C 264

Cononsolvency of PNIPAM in Aqueous Methanol Solutions — •Cahit Dalgicdir¹, Francisco Rodríguez-Ropero², and Nico F. A. van der Vegt¹ — ¹Technische Universität Darmstadt, Darmstadt, Germany — ²Illinois Institute of Technology, Chicago, United States of America

A polymer might dissolve in the pure forms of two different solvents but may precipitate in mixtures of these solvents. This interesting phenomenon is called cononsolvency and poly(N-isopropylacrylamide) (PNIPAM) in aqueous methanol solutions is an example of it. Although cononsolvency for PNIPAM in water/methanol solutions is well known, the underlying mechanism and the driving forces are still under debate. Using extensive molecular dynamics simulations we find that the calorimetric enthalpy of the collapse transition shows a similar pattern compared to cononsolvency.[1] Polymer hydration is found to be the key factor for chain collapse where the hydrogen bonds between the water and the polymer amide are frustrated by methanol. [1]C.Dalgicdir, F.Rodríguez-Ropero, N.F.A. van der Vegt J. Phys. Chem. B, 2017, 121 (32)