TY - JOUR
T1 - Peculiar charging effects on titania in aqueous 1:1, 2:1, 1:2 and mixed electrolyte suspensions
AU - Rosenholm, Jarl B.
AU - Kosmulski, Marek
N1 - Funding Information:
The Academy of Finland is acknowledged for funding throughout the investigations.
PY - 2012/11/1
Y1 - 2012/11/1
N2 - Charging of particles in aqueous suspensions is primarily related to potential determining ions, such as silver and iodide ions at silver halide particle surfaces. Proton is considered as a (secondary) potential determining ion at hydrated metal oxide surfaces. Indifferent electrolytes neutralize at increased concentration the surface charge but do not reverse it. However, in the presence of a non-Coulombic interaction the surface charge may be enhanced or reversed at increased ionic strength. Such interaction is denoted specific which may be due to enhanced van der Waals dipolar, Lewis acid-base, solvation (Hofmeister) and/or Born solvation effects. Alternatively, these interactions have been characterized in terms of (semi) empirical ion and surface properties, such as hard-soft acid-base (HSAB) interaction. Within the Stern layer closest to the particle surface truly specific effects are related to the inner Helmholtz plane (IHP) in order to distinguish them from the charge and solvation related effects occurring within the outer Helmholtz plane (OHP). We review some recent observations on the particular influence of ions on the charging of titania particles in aqueous 1:1, 2:1, 1:2 and mixed electrolyte suspensions.
AB - Charging of particles in aqueous suspensions is primarily related to potential determining ions, such as silver and iodide ions at silver halide particle surfaces. Proton is considered as a (secondary) potential determining ion at hydrated metal oxide surfaces. Indifferent electrolytes neutralize at increased concentration the surface charge but do not reverse it. However, in the presence of a non-Coulombic interaction the surface charge may be enhanced or reversed at increased ionic strength. Such interaction is denoted specific which may be due to enhanced van der Waals dipolar, Lewis acid-base, solvation (Hofmeister) and/or Born solvation effects. Alternatively, these interactions have been characterized in terms of (semi) empirical ion and surface properties, such as hard-soft acid-base (HSAB) interaction. Within the Stern layer closest to the particle surface truly specific effects are related to the inner Helmholtz plane (IHP) in order to distinguish them from the charge and solvation related effects occurring within the outer Helmholtz plane (OHP). We review some recent observations on the particular influence of ions on the charging of titania particles in aqueous 1:1, 2:1, 1:2 and mixed electrolyte suspensions.
KW - ζ-Potential
KW - 1:1, 2:1, 1:2 and mixed electrolytes
KW - Common intersection points
KW - DLVO model
KW - Isoelectric points
KW - Multisite complexation model
KW - Partial charge model
KW - Schultze-Hardy model
KW - Settling
KW - Stern layer adsorption
KW - Titania suspensions
KW - Viscosimetry
KW - Yield stress
UR - http://www.scopus.com/inward/record.url?scp=84865020882&partnerID=8YFLogxK
U2 - 10.1016/j.cis.2012.06.014
DO - 10.1016/j.cis.2012.06.014
M3 - Review Article or Literature Review
AN - SCOPUS:84865020882
SN - 0001-8686
VL - 179-182
SP - 51
EP - 67
JO - Advances in Colloid and Interface Science
JF - Advances in Colloid and Interface Science
ER -