title: Concentration- and pH-dependence of highly alkaline sodium silicate solutions.
abstract: In this study two routes for the gelation of water glass have been investigated; the destabilization by a change in pH and by an increase in concentration through evaporation. Both methods produce optically transparent, highly viscous, homogeneous solutions. The structure and dynamics of the solutions along the two routes have been investigated with dynamic light scattering, (29)Si-Nuclear Magnetic Resonance spectroscopy, viscosity measurements and infrared spectroscopy. We find that the two routes are fundamentally different. Increasing the concentration of the sodium silicate system leaves the silica speciation apparently unchanged. Lowering the pH leads to condensation reactions, thus a change in the silica speciation.
authors.affiliation: Department of Applied Physics, Chalmers University of Technology, Gothenburg, Sweden.
authors.forename: Jonas
authors.initials: J
authors.lastname: Nordström
authors.forename: Erik
authors.initials: E
authors.lastname: Nilsson
authors.forename: Patrik
authors.initials: P
authors.lastname: Jarvol
authors.forename: Moheb
authors.initials: M
authors.lastname: Nayeri
authors.forename: Anders
authors.initials: A
authors.lastname: Palmqvist
authors.forename: Johan
authors.initials: J
authors.lastname: Bergenholtz
authors.forename: Aleksandar
authors.initials: A
authors.lastname: Matic