A technique for estimating the particle-particle interaction energy in a colloidal system through incipient aggregation in an isotropic turbulent field is proposed. With this technique, we first determine experimentally the critical (i.e., minimum) energy dissipation rate that induces aggregation in a given stable colloidal system. Then, assuming DLVO interparticle potentials, we can estimate the surface charge and potential by determining the critical relative trajectory of two particles leading to aggregation. It is worth noting that the interparticle interaction potential estimated by this technique accounts in an effective manner also for all the other non-DLVO interparticle interactions that may be present in the system. In other words, using the surface charge value estimated by this technique in the frame of a DLVO model allows us to reproduce correctly the conditions under which the colloidal system was found experimentally to undergo aggregation in a turbulent field. An experimental verification of the proposed technique is shown using a fluorinated polymer latex. It was found that the obtained value of the surface charge is very close to that measured by conductometric titration and is practically constant in the investigated range of particle volume fraction and ionic strength values. (C) 2002 Elsevier Science (USA).

Characterization of particle interaction energy through incipient turbulent aggregation

MORBIDELLI, MASSIMO
2002-01-01

Abstract

A technique for estimating the particle-particle interaction energy in a colloidal system through incipient aggregation in an isotropic turbulent field is proposed. With this technique, we first determine experimentally the critical (i.e., minimum) energy dissipation rate that induces aggregation in a given stable colloidal system. Then, assuming DLVO interparticle potentials, we can estimate the surface charge and potential by determining the critical relative trajectory of two particles leading to aggregation. It is worth noting that the interparticle interaction potential estimated by this technique accounts in an effective manner also for all the other non-DLVO interparticle interactions that may be present in the system. In other words, using the surface charge value estimated by this technique in the frame of a DLVO model allows us to reproduce correctly the conditions under which the colloidal system was found experimentally to undergo aggregation in a turbulent field. An experimental verification of the proposed technique is shown using a fluorinated polymer latex. It was found that the obtained value of the surface charge is very close to that measured by conductometric titration and is practically constant in the investigated range of particle volume fraction and ionic strength values. (C) 2002 Elsevier Science (USA).
2002
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11311/659677
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