LA PONITtoe CLAY---A SYNTHETIC INORGANIC GELLING AGENT 245 Ethanol/water Figs. 4 and $ show graphs for 25% and 40% ethanol in water systems. e•e•e•e o i 2 3 4 õ •e •. 2% clay -- -- _. ß _ •._•k__• J •ø _. _ I 0-5 I'0 30 • e • 50 O Clay concentration, 0/ø Sodium concentration, me cj-' Figure 4 Effect of clay and electrolyte concentration on ethanol/water {25/75) systems I I 2% cloy I 5 0 0.5 I-0 Cloy concentration. % Sodium concentration, me --io -- 20 .-- -- 40 -- 50 0 -- 60 -- 70 Figure 5 Effect of clay and electrolyte concentration on ethanol/water (40/60) systems As can be seen, the behaviour is similar to that of the methanol/water system, but all the ESS and OD values are slightly higher.

246 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS isoPropanol/water The results are shown in Figs. 6 and 7. The properties are again similar, with yet a further increase o[ both ESS and OD values. ioo 50 [ I o i 2 3 4 5 o Clay concentrot,on, _',,, 0.5 1.0 Sodram concentrotion, me 2% clay 3O • 4O 50 • Figure 6 Effect of clay and electrolyte concentration on isopropanol/water (25/75) systems .50 - I 0 I 2 3 4 5 C lay' concentrahon, % I I 0.5 1,0 2% cloy Sodium concentrotion, me g-• -- io - 20 -30 • -- 50 0 -- 80 -- 70 Figure 7 Effect of clay and electrolyte concentration on isopropanol/xvater (40/60) systems