STUDY OF STRUCTURAL AND ELECTRONIC PROPERTIES OF THE POLYETHYLENEIMINE HEMIHYDRATE

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.