Ion specificity of the zeta potential of α-alumina, and of the adsorption of p-hydroxybenzoate at the α-alumina–water interface

Das, Manash R.; Borah, Jayanta M.; Kunz, Werner; Ninham, Barry W.; Mahiuddin, Sekh

doi:10.1016/j.jcis.2009.12.048

Cited by 74 publications

(64 citation statements)

References 94 publications

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“…It follows that ion site competition may help explain the relatively rare observations of Hofmeister series at low concentrations. [57][58][59] Hofmeister effects are more commonly observed in high salt conditions above 0.1M.…”

Section: A Titania Surfacementioning

confidence: 98%

The impact of the competitive adsorption of ions at surface sites on surface free energies and surface forces

Parsons

Salis

2015

The Journal of Chemical Physics

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The impact of the competitive adsorption of ions at surface sites on surface free energies and surface forces The relationship between surface charge and surface potential at the solid-liquid interface is often determined by a charge regulation process, the chemisorption of a potential determining ion such as H + . A subtle ion-specific effect can be observed when other ions compete with the primary potential determining ion to bind to a surface site. Site competition may involve alternative ions competing for a first binding site, e.g., metals ions competing with H + to bind to a negatively charged oxide or carboxyl site. Second-binding sites with site competition may also be found, including amphoteric OH + 2 sites, or anion binding to amine groups. In this work, a general theoretical model is developed to describe the competitive adsorption of ions at surface sites. Applied to the calculation of forces, the theory predicts a 20% increase in repulsion between titania surfaces in 1 mM NaCl, and a 25% reduction in repulsion between silica surfaces in 0.1M NaCl compared to calculations neglecting ion site competition. C 2015 AIP Publishing LLC. [http://dx

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Section: A Titania Surfacementioning

confidence: 98%

The impact of the competitive adsorption of ions at surface sites on surface free energies and surface forces

Parsons

Salis

2015

The Journal of Chemical Physics

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“…The cation species with larger main and angular quantum numbers have "softer" electron cloud which then exhibit much stronger quantum fluctuation, resulting in a stronger polarization effect when interacting with the negatively charged particle surface. 33 The higher the polarizability of cations, higher is the propensity for the particle surface, 14,30 indicating that these cation species can be more effective to precipitate the colloidal minerals, and this is the production of Hofmeister effects in aggregation of colloidal minerals.…”

Section: Impact Of Electric Field On Hofmeister Effects In Aggregatiomentioning

confidence: 99%

“…However, further studies indicated that Hofmeister effects are also present at low electrolyte concentration (<100 mmol/L or even lower). 3,14,[28][29][30][31][32] In addition, Hofmeister effects are found to be more pronounced at very dilute concentration, 11,31,33,34 but classical theories including hydration effects, ionic size and dispersion force could not give a reasonable interpretation to this phenomenon. 34 Fortunately, several recent studies [33][34][35] have disclosed the essential role of polarization effect played in Hofmeister effects at interface surfaces, and these results provided motivation for us.…”

Section: Introductionmentioning

confidence: 99%

“…4 Over the last decades, Hofmeister effects have been observed ubiquitously in colloidal, nanocrystal and biological systems, including bacteria growth, 5,6 enzyme activity, [7][8][9] colloidal stability, 3,10 cation exchange equilibrium 11 and mineral dissolution. 12 These effects can influence the interactions of ions with different interfaces (metal/water, air/water, oil/water and water/solid), 13,14 as well as affect the physicochemical properties of the solution or colloids, such as activity coefficient, Zeta potential, freezing point, osmotic pressure, photoluminescence and catalytic properties. [14][15][16][17][18][19][20] The widespread applicability of Hofmeister effects in different fields and their unclear origin make the clarification of the underlying mechanism one of the tremendous challenges in interfacial and colloidal science.…”

Section: Introductionmentioning

confidence: 99%

“…12 These effects can influence the interactions of ions with different interfaces (metal/water, air/water, oil/water and water/solid), 13,14 as well as affect the physicochemical properties of the solution or colloids, such as activity coefficient, Zeta potential, freezing point, osmotic pressure, photoluminescence and catalytic properties. [14][15][16][17][18][19][20] The widespread applicability of Hofmeister effects in different fields and their unclear origin make the clarification of the underlying mechanism one of the tremendous challenges in interfacial and colloidal science. Many efforts have been made to uncover the origin of Hofmeister effects.…”

Section: Introductionmentioning

confidence: 99%

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Impact of electric field on Hofmeister effects in aggregation of negatively charged colloidal minerals

Tang

Zhu

et al. 2016

J Chem Sci

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Abstract. In this study, the aggregation kinetics of negatively charged colloidal minerals in Na2+ , Ca 2+ and Cu 2+ solutions were measured and Hofmeister effects therein were estimated through total average aggregation (TAA) rates and critical coagulation concentration (CCC). Hofmeister effects of TAA rates increased exponentially with the increase in electric field strength, which cannot be explained by the classical theories (i.e., ionic size, hydration and dispersion forces), indicating strong electric field at colloidal surface was an indispensable factor in studying Hofmeister effects. Meanwhile, Hofmeister series of CCC values Nashow fine correlation with the polarization of various cations, implying that onic polarization in strong electric field would be responsible for Hofmeister effects in aggregation of colloidal minerals, and the deduction was confirmed by the calculated results of electrostatic interactions between colloidal minerals.

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Carbon Bead‐Supported Ethylene Diamine‐Functionalized Carbon Nanofibers: An Efficient Adsorbent for Salicylic Acid

Talreja

Verma

Kumar

2016

CLEAN Soil Air Water

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The present study describes the removal of salicylic acid (SA) from water by adsorption using ethylene diamine (EDA)-functionalized carbon nanofibers (CNFs)-containing porous carbon beads ($0.5 mm). Briefly, the phenolic beads, separately synthesized using suspension polymerization, were carbonized and activated. The CNFs were grown on the carbon beads, using chemical vapor deposition, and the prepared fibrous beads functionalized with EDA were used as an adsorbent for SA. The prepared materials were characterized by their physico-chemical properties, including specific surface area, surface morphology, and surface functional groups. The adsorption tests performed over the initial SA concentration range of 100-1500 mg/L revealed the adsorption capacity of the materials to be $682 mg/g, which was considerably larger than that of the adsorbents discussed in the literature for SA. The zeta-potential analysis attributed enhanced adsorption to the electrostatic interaction and hydrogen bonding between the solute molecules and the EDA-functionalized surface of the CNFs. The material and method developed in this study for the remediation of the SA-laden wastewater may be extended to other acidic pollutants present in pharmaceutical effluents.

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Ion specificity of the zeta potential of α-alumina, and of the adsorption of p-hydroxybenzoate at the α-alumina–water interface

Cited by 74 publications

References 94 publications

The impact of the competitive adsorption of ions at surface sites on surface free energies and surface forces

The impact of the competitive adsorption of ions at surface sites on surface free energies and surface forces

Impact of electric field on Hofmeister effects in aggregation of negatively charged colloidal minerals

Carbon Bead‐Supported Ethylene Diamine‐Functionalized Carbon Nanofibers: An Efficient Adsorbent for Salicylic Acid

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