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DOI: 10.5445/IR/1000045599

On the Relation between Natural and Enforced Syneresis of Acidic Precipitated Silica

Wilhelm, S.; Kind, M.

Silica in industrial production processes is precipitated by mixing an acid and an inorganic precursor. In this aqueous solution, silica particles form due to a polymerization reaction and agglomeration and, finally, build a gel. Thereafter, the reaction continues, and the gel network shrinks with the expulsion of the enclosed pore liquid. This slow process is known as "natural syneresis" and strongly affects the product properties, such as the agglomerate size, specific surface or porosity of the silica produced. In order to investigate the influence of process parameters, such as temperature, pH or ionic strength, on the shrinkage in shorter time-scales, we propose an acceleration of this process and define it as "enforced syneresis". The acceleration is performed by applying a mechanical external force to the gel by means of a plunger and measuring the shrinkage behavior under these conditions. Thereby, the conceptual idea is the prediction of the shrinkage due to natural syneresis based on the results of enforced syneresis. We are now able to predict the natural syneresis behavior from enforced syneresis data ... mehr

Zugehörige Institution(en) am KIT Institut für Thermische Verfahrenstechnik (TVT)
Publikationstyp Zeitschriftenaufsatz
Jahr 2014
Sprache Englisch
Identifikator ISSN: 2073-4360
URN: urn:nbn:de:swb:90-455999
KITopen ID: 1000045599
Erschienen in Polymers
Band 6
Heft 12
Seiten 2896-2911
Bemerkung zur Veröffentlichung Gefördert durch den KIT-Publikationsfonds
Schlagworte Enforced; Natural; Precipitation; Prediction model; Shrinkage; Silica; Syneresis
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