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The influence of both polymer chain length and concentration on the mobility of solvent molecules in polymer solutions was studied by Monte Carlo simulations with the use of the dynamic lattice liquid (DLL) model. The poly(vinylmethylether)-water system was used as a model. Two different solvent (water) states with differing mobilities were distinguished in polymer solutions. The first one with high molecular mobility independent of polymer concentration corresponds to bulk solvent in real systems. The second state relates to so called bound solvent. In this case the solvent diffusivity decreases with polymer content. For diluted solutions the diffusion of bound solvent is affected by polymer chain length, precisely, by the ability of the polymer chain to undergo coil formation.

Thermo-responsive materials, such as poly(vinylmethylether) (PVME), attract a common attention because of their unique physical properties resulted from metastable equilibrium between various types of interactions. In this work Monte Carlo (MC) and quantum-mechanical (QM) methods were used to study excluded volume and electrostatic interactions respectively. The graining procedure of PVME-water system was proposed. Its implementation to MC calculations allowed to distinguish how two water fractions differ on dynamics. The QM calculations showed that the formation of cyclic clusters leads to the lengthening of the hydrogen bonds and consequently to higher energies in comparison to linear forms, which is crucial looking at an application of QM results to MC calculation considering thermal interactions.

Thermo‐responsive polymer hydrogels attract a great attention because of their unique behavior in response to changes in the thermal environment. It is related to metastable intermolecular interactions resulting in volume phase transitions (VPT). The hydration of poly(2‐(2‐methoxyethoxy)ethyl methacrylate) (PMEO2MA)‐based materials was studied by Raman spectroscopy and further supported by density functional theory calculations. Hydrogels based on random networks prepared via radiation‐induced free radical polymerization and cross‐linking were compared with hydrogels with more regular structure formed by atom transfer radical polymerization. Two types of regular networks were studied: bare one and decorated by linear dangling chains. It was found that both, the total bound water surrounding the polymer chains (~11 H2O per polymer unit) and accessibility of CO groups for water molecules, are independent of topology of PMEO2MA network. Contrarily, network architecture strongly influences CO–water complex stability, which decreases in a following order: regular bare network, irregular bare network, regular decorated network. It was also shown that the stability of CO–water complex is correlated with VPT temperature in PMEO2MA hydrogels. These studies prove a key role of polymer hydration in its thermo‐responsive properties. Copyright © 2016 John Wiley & Sons, Ltd.

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