Artículos de revistas
Surface charge density determination in electric double layered magnetic fluids
Fecha
2002Registro en:
Autor
Tourinho, Francisco Augusto
Campos, Alex Fabiano Cortez
Silva, Renata Aquino da
Lara, Maria Cristina Figueiredo Lima e
Silva, Gerlado José da
Depeyrot, Jérôme
Institución
Resumen
We analyze potentiometric and conductimetric measurements, simultaneously performed in several complex systems (Brönsted acid-base-type). The results show an excellent agreement between reported and obtained values of the dissociation constants of the involved equilibria. A similar analysis is proposed to account, in electric double layered magnetic fluids (EDL-MF), for the charging of the particle surface based on a proton transfer proccess at the interface with the bulk dispersion. This model allows to relate the pH dependence of the phase diagram to the variations of the nanoparticle surface charge density, which leads to a useful method to monitor the colloidal stability of EDL-MF.