Repeptization by dissolution in a colloidal system of iron(III) pyrophosphate
Y Mikal van Leeuwen1, Krassimir P Velikov, Willem K Kegel
1Van 't Hoff Laboratory for Physical and Colloidal Chemistry, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands. Y.M.vanleeuwen@uu.nl
Abstract:
Repeptization (redispersion) from an aggregated state is usually only possible in charge-stabilized colloidal systems if the system is either coagulated in the secondary minimum of the interaction potential or if the system cannot settle completely into the primary minimum. In this work, we analyze the zeta potential, conductivity, and long-term stability of colloidal systems of iron(III) pyrophosphate and surprisingly find that the system seems to defy conventional wisdom as it can be repeptized from its coagulated state regardless of aging time and background ions. Moreover, after having been stored for up to a month in 2 M NaCl, dialysis of iron pyrophosphate will yield a colloidal dispersion that is actually stable for a longer period of time than a fresh system with background electrolyte removed.
Related Concept Videos
Washing, Drying, and Ignition of Precipitates
Precipitation and Co-precipitation
Colloidal precipitates
Factors Affecting Solubility
Acid Mine Drainage
Precipitation Processes


