Formation of two-dimensional networks of oligoepoxide in Langmuir monolayers on the surface of heteropolyacid aqueous solutions

The kinetics of chemical transformations in monolayers of an epoxy oligomer on the surface of aqueous solutions of phosphotungstic acid was studied Two-dimensional polymerization of the oligomer resulted in a crosslinked polymer, as was demonstrated using the surface balance technique, FTIR spectroscopy, and gel-sol analysis. The weight fraction of the polymer in the monolayer was 85% after 24 h. It was established that the polymerization process had a topochemical character, resulting in an increase in the monolayer limiting area by a factor of 4.5 and the monolayer collapse pressure by a factor of 16. In the course of polymerization, a mixed nanostructured monolayer was formed from an epoxy polymer and heteropolyanions, which were immobilized inside the cross-linked domains of the two-dimensional matrix and retained the Keggin structure. When the polymerization was carried out on the surface of a subphase with a neutralized heteropolyacid, the epoxy oligomer was not polymerized and no heteropolyanions were incorporated into the oligomer monolayer.