Combined experimental and theoretical investigations of clay–polymer nanocomposites: intercalation of single bifunctional organic compounds in Na+-montmorillonite and Na+-hectorite clays for the design of new materials

Abstract

This paper reports a study of the intercalation of single bifunctional poly(ethylene oxide)- and poly(propylene oxide)-based compounds, with and without modified end groups, in Na⁺-montmorillonite and Na⁺-hectorite clays as the starting point for the design of new non-exfoliated clay–polymer materials. The terminal functional groups employed on intercalated poly(ethylene oxide) and poly(propylene oxide) include acrylate, methacrylate and amine functions. For some of the monomers, in situ polymerisation was observed. Attempts to rationalise these behaviours are made on the basis of atomistic grand canonical Monte Carlo, canonical Monte Carlo and molecular dynamics simulations. Poly(ethylene oxide) diacrylate monomers, for which in situ polymerisation was observed, interact more strongly with the Na⁺-montmorillonite clay layers than the other monomers.