Study of Structural and electronic properties
of the polyethyleneimine hemihydrate
D. Diabaté1*, G. Herlem2, A. Yapo1, A. Trokourey1, A. Koné1, B. Fahys2
1Université de Cocody, UFR SSMT, Laboratoire de Chimie Physique, 22 BP 582 Abidjan 22, Côte-d’Ivoire.
2Université de Franche-Comté, UFR Sciences et Techniques, Laboratoire de Chimie de Matériaux,
16 Route de Gray F25030 Besançon, France
* Corresponding author. E-mail: email@example.com
Received: 15 January 2007; revised version accepted: 04 July 2007
From all of the known polyethyleneimine crystalline forms, we focused our study on the hydrate one that can have 0.5 water molecule per ethyleneimine monomeric unit. The hydration of the anhydrous polyethyleneimine made of double - stranded helix yields planar zigzag polymer chains. From the partial hemihydrate crystal lattice, we propose a resolved and optimized complete structure by means of ab initio density functional theory calculations. Water molecules take place in the center of a tetrahedron quasi square planar structure made of four nitrogen atoms. Contrary to the small gap semiconducting anhydrous polyethyleneimine, the hemihydrate polyethyleneimine has an insulating character.
Keywords: Polyethyleneimine; Density functional theory; Phonons.