Record details

Title
    Interaction of Freshly Precipitated Silica Gel with Aqueous Silicic Acid Solutions under Ambient and Near Neutral pH-conditions: A Detailed Analysis of Linear Rate Law
Author
    Blecha, Martin
    Faimon, Jiří
Language
    anglicky
Publication type
    článek v periodiku
Source title - serial
    Aquatic Geochemistry
Vol./nr.
    Roč. 14, č. 1
Pages
    40
Year
    2008
Thesaurus term
    Dissolution
    Dynamics
    Error
    Experiment
    Flux
    Growth
    Model
    Reversibility
    Silica gel
Keyword
    Acid
    Ambient
    Analysis
    Aqueous
    Detailed
    Freshly
    Gel
    Interaction
    Law
    Linear
    Near
    Neutral
    PH-conditions
    Precipitated
    Rate
    Silica
    Silicic
    Solutions
Abstract (in english)
   Interaction of freshly precipitated silica gel with aqueous solutions was studied at laboratory batch experiments under ambient and near neutral pH-conditions. The overall process showed excellent reversibility: gel growth could be considered as an opposite process to dissolution and a linear rate law could be applied to experimental data. Depending on the used rate law form, the resulting rate constants were sensitive to errors in parameters/variables such as gel surface area, equilibrium constants, Si-fluxes, and reaction quotients. The application of an Integrated Exponential Model appeared to be the best approach for dissolution data evaluation. In contrast, a Differential Model gave best results for growth data modeling. An universal value of activation energy for growth of any silica polymorph is not consistent with the value for silica gel growth, which questions the hypothesis about one unique activated complex controlling the silica polymorph growth.
Contributor
    MU Brno, Přírodovědecká fakulta
Contributor code
    MU, PřF
Source format
    R
Import date
    8. 8. 2012