Regensburg 2010 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 4: Focus: Structure and Dynamics of Responsive Hydrogels II

CPP 4.2: Vortrag

Montag, 22. März 2010, 14:30–14:45, H37

Molecular simulation study of the volume transition of hydrogels — •Jonathan Walter¹, Viktor Ermatchkov¹, Jadran Vrabec², and Hans Hasse¹ — ¹Laboratory of Engineering Thermodynamics, University of Kaiserslautern, 67663 Kaiserslautern, Germany — ²Thermodynamics and Energy Technology, University of Paderborn, 33098 Paderborn, Germany

Hydrogels are three-dimensional networks of hydrophilic polymers. The swelling behaviour, one of their most interesting properties, is determined by their network properties and the external conditions. The volume transition of hydrogels mainly depends on the nature of the polymer backbone and the solvent. The cross-linker usually only has a minor influence. This allows studying the volume transition of hydrogel by simulations of the computationally much less expensive polymer strand + solvent system. The volume transition of the hydrogel then corresponds to the change of the polymer strand between its collapsed form in a poor solvent and its stretched form in a good solvent. Here, the swelling and collapsing of Poly(N-isopropylacrylamide) is studied by molecular dynamics simulation on the basis of transferable all-atom and united-atom force fields using explicit solvent models from different literature sources. This work focuses on the influence of the temperature and solvent composition on the volume transition of the hydrogel. It is shown that the molecular simulations allow qualitative predictions of the swelling behaviour observed in experiments.