Conductivity studies on modified laponites

Significant increase of the a.c. conductivity of Laponite is achieved when the sodium form is totally exchanged with potassium ions; however, the rheological properties alter, e.g. the clay will no longer form a gel with water. Exchange with Li⁺, Rb⁺, Cs⁺ or Cu²⁺ produces no increase in the a.c. conductivity over that of the sodium form. The synthesis of fluoro-laponites, with increased sodium contents, via a sol-gel method, gives materials of enhanced a.c. conductivity, which retain similar rheological properties to those of commercial Laponite. Some ²⁹Si and ⁶Li MAS NMR data are reported for the new materials.