title: Poly(vinyl methyl ether) hydrogels at temperatures below the freezing point of water-molecular interactions and states of water.
abstract: Water interacting with a polymer reveals a number of properties very different to bulk water. These interactions lead to the redistribution of hydrogen bonds in water. It results in modification of thermodynamic properties of water and the molecular dynamics of water. That kind of water is particularly well observable at temperatures below the freezing point of water, when the bulk water crystallizes. In this work, we determine the amount of water bound to the polymer and of the so-called pre-melting water in poly(vinyl methyl ether) hydrogels with the use of Raman spectroscopy, dielectric spectroscopy, and calorimetry. This analysis allows us to compare various physical properties of the bulk and the pre-melting water. We also postulate the molecular mechanism responsible for the pre-melting of part of water in poly(vinyl methyl ether) hydrogels. We suggest that above -60 °C, the first segmental motions of the polymer chain are activated, which trigger the process of the pre-melting.
authors.affiliation: Department of Molecular Physics, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland ; Institute of Experimental Physics, University of Warsaw, Hoza 69, 00-681 Warsaw, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Pastorczak
authors.affiliation: Department of Molecular Physics, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland ; Technological Lab of Uruguay (LATU), 6201 Av. Italia, 11500 Montevideo, Uruguay.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Dominguez-Espinosa
authors.affiliation: Department of Molecular Physics, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland.
authors.forename: Lidia
authors.initials: L
authors.lastname: Okrasa
authors.affiliation: Department of Chemistry, Rzeszow University of Technology, Powstancow Warszawy 6, 35-959 Rzeszow, Poland.
authors.forename: Marek
authors.initials: M
authors.lastname: Pyda
authors.affiliation: Department of Molecular Physics, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Kozanecki
authors.affiliation: Institute of Applied Radiation Chemistry, Lodz University of Technology, Wroblewskiego 15, 93-590 Lodz, Poland.
authors.forename: Slawomir
authors.initials: S
authors.lastname: Kadlubowski
authors.affiliation: Institute of Applied Radiation Chemistry, Lodz University of Technology, Wroblewskiego 15, 93-590 Lodz, Poland.
authors.forename: Janusz M
authors.initials: JM
authors.lastname: Rosiak
authors.affiliation: Department of Molecular Physics, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland.
authors.forename: Jacek
authors.initials: J
authors.lastname: Ulanski
keywords: DSC; Dielectric spectroscopy; Molecular interactions; PVME hydrogels; Raman spectroscopy; Water pre-melting
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