Öppna denna publikation i ny flik eller fönster >>2018 (Engelska)Ingår i: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 528, s. 336-348Artikel i tidskrift (Refereegranskat) Published
Abstract [en]
Aggregation and breakup of small particles in stirred suspensions often shows an overshoot in the time evolution of the mean cluster size: Starting from a suspension of primary particles the mean cluster size first increases before going through a maximum beyond which a slow relaxation sets in. Such behavior was observed in various systems, including polymeric latices, inorganic colloids, asphaltenes, proteins, and, as shown by independent experiments in this work, in the flocculation of microalgae. This work aims at investigating possible mechanism to explain this phenomenon using detailed population balance modeling that incorporates refined rate models for aggregation and breakup of small particles in turbulence. Four mechanisms are considered: (1) restructuring, (2) decay of aggregate strength, (3) deposition of large clusters, and (4) primary particle aggregation where only aggregation events between clusters and primary particles are permitted. We show that all four mechanisms can lead to an overshoot in the mean size profile, while in contrast, aggregation and breakup alone lead to a monotonic, "S" shaped size evolution profile. In order to distinguish between the different mechanisms simple protocols based on variations of the shear rate during the aggregation-breakup process are proposed.
Ort, förlag, år, upplaga, sidor
Academic Press, 2018
Nyckelord
Population balance modeling, Colloidal aggregation, Shear aggregation, Aggregate breakup, Restructuring, Flocculation, Fractal aggregates, Turbulence
Nationell ämneskategori
Kemi
Identifikatorer
urn:nbn:se:kth:diva-233260 (URN)10.1016/j.jcis.2018.05.064 (DOI)000440127000036 ()29885609 (PubMedID)2-s2.0-85048509507 (Scopus ID)
Forskningsfinansiär
Vetenskapsrådet, 2012-6216
Anmärkning
QC 20180817
2018-08-172018-08-172022-06-26Bibliografiskt granskad