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dc.contributor.authorDelgado Mora, Ángel Vicente 
dc.contributor.authorAhualli Yapur, Silvia Alejandra 
dc.contributor.authorJiménez Olivares, María Luisa 
dc.contributor.authorArroyo, Francisco J.
dc.contributor.authorCarrique, Félix
dc.identifier.citationA.V. Delgado, Advances in Colloid and Interface Science, []es_ES
dc.descriptionFinancial support from Ministerio de Ciencia, Innovación y Universidades (Spain) ( GC2018-098770-B-I00 ), and Junta de Andalucía (Spain) and European Funds for Regional Development ( BF-FQM-141-UGR18 , PI20-00233 ) is gratefully acknowledged.es_ES
dc.descriptionFinancial support from Ministerio de Ciencia, Innovación y Universidades (Spain) (GC2018-098770-B-I00), and Junta de Andalucía (Spain) and European Funds for Regional Development (BF-FQM-141-UGR18, PI20-00233) is gratefully acknowledged.es_ES
dc.description.abstractBecause of their singular phenomenology, the so-called salt-free colloids constitute a special family of dispersed systems. Their main characteristic is that the dispersion medium ideally contains only the solvent and the ions compensating exactly the surface charge of the particles. These ions (often called released counterions) come into the solution when the surface groups responsible for the particles charge get ionized. An increasing effort is nowadays dedicated to rigorously compare theoretical model predictions for ideal salt-free suspensions, where only the released counterions are supposed to be present in solution, with appropriately devised experiments dealing with colloids as close as possible to the ideal salt-free ones. Of course, if the supporting solution is aqueous, the presence of atmospheric contamination and any other charged species different from the released counterions in the solution must be avoided. Because this is not an easy task, the presence of dissolved atmospheric CO2 and of H+ and OH− from water dissociation cannot be fully discarded in aqueous salt-free solutions (often denominated realistic in such case). Ultimately, at some point, the role of the released counterions will be comparable or even larger in highly charged concentrated colloids than that of added salts. These topics are covered in the present contribution. The model results are compared with experimental data on the dynamic mobility and dielectric dispersion of polystyrene spheres of various charges and sizes. As a rule, it is found that the model correctly predicts the significance of alpha and Maxwell-Wagner-O'Konski relaxations. Positions and amplitudes of such relaxations are well predicted, although it is necessary to assume that the released counterions are potassium or sodium instead of protons, otherwise the frequency spectra of experimental mobility and permittivity differ very significantly from those theoretically calculated. The proposed electrokinetic evaluation is an ideal tool for detecting in situ the possible contamination (or incomplete ion exchange of the latexes). A satisfactory agreement is found when potassium counterions are assumed to be in solution, mostly if one considers that the comparison is carried out without using any adjustable parameters.es_ES
dc.description.sponsorshipMinisterio de Cienciaes_ES
dc.description.sponsorshipMinisterio de Ciencia, Innovación y Universidades GC2018-098770-B-I00es_ES
dc.description.sponsorshipEuropean Regional Development Fund BF-FQM-141-UGR18, PI20-00233es_ES
dc.description.sponsorshipJunta de Andalucíaes_ES
dc.rightsAtribución-NoComercial-SinDerivadas 3.0 España*
dc.subjectAC electrokineticses_ES
dc.subjectAdded counterionses_ES
dc.subjectDielectric dispersiones_ES
dc.subjectDynamic mobilityes_ES
dc.subjectPolystyrene sphereses_ES
dc.titleElectrokinetic detection of the salt-free condition in colloids. Application to polystyrene latexeses_ES

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Atribución-NoComercial-SinDerivadas 3.0 España
Except where otherwise noted, this item's license is described as Atribución-NoComercial-SinDerivadas 3.0 España