“…The nanometer-scale material which has been most investigated is layered clay, primarily including layered silicates (montmorillonite (MMT) is the most studied member of this family) [9,10,11]. Other nanometer dimension materials that have been studied include layered double hydroxides (LDHs) [12,13,14,15] and carbon nanotubes, either single-, double- or multi-wall [16,17,18,19,20,21,22,23,24,25].…”