Salt Identity Effects On Aqueous Laponite Suspensions
Abstract: Electrostatic interactions of laponite have been studied for about half a century. Extensive work has been done in deciphering the salt-laponite phase diagram, however, the bulk of the effort has focused exclusively on the role of sodium chloride. This paper explores the individual effects of two monovalent salts and one divalent salt in phase transitions of aqueous laponite systems. A dilution technique from literature was utilized to first confirm the phase of a salt-free laponite sample at the concentration used in this study. We have observed that at equivalent ionic strength solution ranges across the different salts, there is significant variation in the rheology. Rheometric analyses varying strain and frequency have revealed a higher storage modulus for CaCl2 than for LiCl and NaCl. Additional work still needs to be done to quantitatively assess the microstructures and confirm the transitions between the various nonergodic states.
Gabriela Diaz*, David Delgado, Dr. Kenneth Shull
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