pH mediated delamination of anionic clay-like nickel–zinc hydroxysalt in water through intercalation of zwitterionic p-aminobenzoate ions

Abstract

p-aminobenzoate could be intercalated into the anionic clay, Ni₃Zn₂(OH)₈(OAc)₂⋅2H₂O at a high pH (∼10). When the pH was reduced to ∼7 while washing colloidal dispersion due to delamination was observed. The development of partial positive charge on the amine end of the intercalated anion causes repulsion between the layers leading to delamination and colloidal dispersion of monolayers in water. The layers could be restacked from the colloid to form the parent solid either by increasing the pH or by evaporation.