Local Structure and Dynamics of Water Absorbed in Poly(ether imide): A Hydrogen Bonding Anatomy.
Hydrogen bonding (HB) interactions play a major role in determining the behavior of macromolecular systems absorbing water. In fact, functional and structural properties of polymer-water mixtures are affected by the amount and type of these interactions. This contribution aims at a molecular level understanding of the interactional scenario for the technologically relevant case of the poly(ether imide)-water system. The problem has been tackled by combining different experimental and theoretical approaches which, taken together, provide a comprehensive physical picture. Relevant experimental data were gathered by in situ FTIR spectroscopy, while molecular dynamics (MD) and statistical thermodynamics approaches were used as modeling theoretical tools. It was found that, among the possible configurations, some are strongly prevailing. In particular, water molecules preferentially establish water bridges with two carbonyl groups of the same PEI repeating unit. Water self-interactions were also detected, giving rise to a "second shell" species in the prevalent form of dimers. The population of the different water species was evaluated spectroscopically, and a remarkable agreement with theoretical predictions was found.
Department of Chemistry and Biology "Adolfo Zambelli", University of Salerno , Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy.
Antonio
0000-0002-9581-6226
A
de Nicola
Department of Chemical Sciences, Federico II University of Naples Via Cintia , Complesso Monte S. Angelo, 80126 Napoli, Italy.
Andrea
A
Correa
Department of Chemistry and Biology "Adolfo Zambelli", University of Salerno , Via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy.|Institute on Polymers, Composites and Biomaterials, National Research Council of Italy , Via Campi Flegrei 34, 80078 Pozzuoli (NA), Italy.
Giuseppe
G
Milano
Institute on Polymers, Composites and Biomaterials, National Research Council of Italy , Via Campi Flegrei 34, 80078 Pozzuoli (NA), Italy.
Pietro
P
La Manna
Institute on Polymers, Composites and Biomaterials, National Research Council of Italy , Via Campi Flegrei 34, 80078 Pozzuoli (NA), Italy.
Pellegrino
0000-0001-6307-1410
P
Musto
Institute on Polymers, Composites and Biomaterials, National Research Council of Italy , Via Campi Flegrei 34, 80078 Pozzuoli (NA), Italy.|Department of Chemical, Materials and Production Engineering, University of Naples Federico II , Piazzale Tecchio 80, 80125 Naples, Italy.
Giuseppe
G
Mensitieri
Department of Chemical, Materials and Production Engineering, University of Naples Federico II , Piazzale Tecchio 80, 80125 Naples, Italy.
Giuseppe
G
Scherillo