A small-angle neutron scattering study of a commercial organoclay dispersion

The paper explores the capacity of small angle neutron neutron scattering (SANS) to characterize the dispersion of an exchanged clay in an organic solvent. As an illustration, results are reported for 1% and 2% by mass suspensions of a representative commercial complex, known as Cloisite, C15A in toluene. C15A is prepared from montmorillonite and the cation ditallow (a naturally occurring variant of dimethydioctodecylammonium). For this particular example, the SANS scattered intensity data suggest that the complex is well dispersed into clusters which consist of a stack of between three and six ditallow-coated montmorillonite platelets. The size of the clusters, the amount of ditallow adsorbed on a montmorillonite platelet, and an estimate of the thickness of the adsorbed layer are evaluated. General comments on the fitting of SANS data obtained from a cluster composed of stacked, coated disks are given.