engleski

Electrokinetics of ripidolite and beidellite clays

Ripidolite and beidillite show high negative electrokinetic potentials in the range from pH=2 (-10 mV; and 20 mV) to pH 10 (-60 mV; and 50 mV, respectively). Experiments were done of mechanical particle disintegration (dry milling), mimicking natural wear and weathering, resulting in increase of specific surface area (12.3 and 1.5 times) and of the cation exchange capacity (3.2, and 1.2 times, respectively). Such small particles, as shown by SEM and HRTEM figures, retain the crystal structure (X-ray) and surface bonds (FT-IR) unchanged, exhibiting reversal of charge (at pH 6.0, and 3.0, respectively). It was interpreted as creation of positively charged surfaces. These new surfaces exposed to fulvic acid in solution of NaCL at pH 6 showed no reversal of charge, but only a decrease for ripidolite, and no influence on beidellite.

electrokinetic measurements; ripidolite; beidellite clay

nije evidentirano