pH-dependent surface charging and points of zero charge

Kosmulski, Marek

doi:10.1016/j.jcis.2006.01.003

Cited by 312 publications

(161 citation statements)

References 18 publications

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“…closer to the reported value of pH 8-10. 13,[24][25][26] In a recent study by Kershner et al, 16 it was shown that crystalline alumina powder with relatively uniform shapes (Sumitomo AA-2) has p.z.c. at pH 3.8, while random-shaped alumina powder They found that -Al 2 O 3 platelets with mainly (0001) surfaces had a p.z.c.…”

Section: Discussionmentioning

confidence: 99%

Structures and Charging of α-Alumina (0001)/Water Interfaces Studied by Sum-Frequency Vibrational Spectroscopy

et al. 2008

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Sum-frequency vibrational spectroscopy in the OH stretch region was employed to study structures of water/ -Al 2 O 3 (0001) interfaces at different pH values. Observed spectra indicate that protonation and deprotonation of the alumina surface dominate at low and high pH, respectively, with the interface positively and negatively charged accordingly. The point of zero charge (p.z.c.) appears at pH ~6.3, which is close to the values obtained from streaming potential and second harmonic generation studies. It is significantly lower than the p.z.c. of alumina powder. The result can be understood from the pK values of protonation and deprotonation at the water/ -Al 2 O 3

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Section: Discussionmentioning

confidence: 99%

Structures and Charging of α-Alumina (0001)/Water Interfaces Studied by Sum-Frequency Vibrational Spectroscopy

et al. 2008

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“…For this reason, the IEP is less a parameter of the particle phase but rather a characteristic parameter of the suspension. In a couple of papers, Kosmulski reviewed experimentally determined PZC and IEP-values for numerous materials in varying environments (Kosmulski 2002(Kosmulski , 2004(Kosmulski , 2006(Kosmulski , 2009.…”

Section: Zeta-potentialmentioning

confidence: 99%

Fundamentals in Colloid Science

Babick

2016

Suspensions of Colloidal Particles and Aggregates

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Preparation and handling of colloidal suspension or even their characterisation is not possible without a basic understanding of the physical effects that prevail on the microscopic level. Some of these effects are directly related to the fineness of the particles because it coincides with a large specific surface area (which corresponds, e.g., to a high adsorption capacity), a considerably curvature of the particle surface (which i. a. promotes dissolution), a high number concentration (i.e. significant osmotic pressure and large collision frequencies), small interparticle distances (i.e. strong interactions between scattered waves), low particle mass (i.e. low weight and inertia), or with the fact that the wavelength of light is larger than particle size (i.e. weak optical scattering). A further effect of the small size of colloidal particles is that their diffusive motion is much faster than for micrometre particles. Moreover, the interactions between colloidal particles are decisive for the macroscopic behaviour of the whole suspension (e.g. with regard to rheology or coagulation). These interactions may be attractive and/or repulsive and depend on the chemical nature and the material properties of the particles. Most of all, they are affected by the interfacial properties which reflect the physico-chemical interaction between the particulate phase, the solvent, and the solutes (e.g. hydrophobicity, adsorption, surface charging).This chapter provides a brief introduction to the fundamentals in colloid science. It addresses the physico-chemical properties of single colloidal particles as well as the processes at the interface and the structure of the interfacial layer. It further examines the non-viscous interactions that occur among colloidal particles. For detailed explanation, the reader is referred to the textbooks of Adamson and Gast

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“…The nanoparticles of silica attained a negative charge by deprotonation at pH > 2 ( Fig. 1), and for alumina surfaces such deprotonation occurred at pH > 8 [31]. Thus, alumina surfaces and silica nanoparticles have surface charges with opposite sign between pH = 2 and 8 and thus experience an attraction by electric diffuse double layer interactions [32].…”

Section: Analysis Of the Deposition Kineticsmentioning

confidence: 99%

Deposition of silica nanoparticles onto alumina measured by optical reflectometry and quartz crystal microbalance with dissipation techniques

Güleryüz

Kaus

Buron

et al. 2014

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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2 Graphical abstractOptical reflectometry and a quartz crystal microbalance with dissipation detection studies showed that the surface coverage and formation of multilayers of silica nanoparticles on alumina was controlled by the electric diffuse double layer interactions between the substrate and the depositing particles.3 Highlights  Deposition of nanoparticles was monitored by optical and gravimetric techniques. Deposition behaviour monitored by independent techniques correlated well. Electron microscopy confirmed deposition behaviour. Surface coverage depended on differential levels of repulsive interactions. Multilayer of nanoparticles was deposited by eliminating repulsive interactions. 4 AbstractUnderstanding of the interactions between particles and the substrate is important for successful sol-gel deposition of thin films. We have studied the deposition of silica nanoparticles on alumina coated surfaces in aqueous electrolytes by optical reflectometry (OR) and a quartz crystal microbalance with dissipation (QCM-D). The deposition of negatively charged silica nanoparticles on positively charged alumina was primarily controlled by the electric diffuse double layer interactions between the substrate and the deposited particles, modulated by the counter-ion release. The build up of a negative charge on the positively charged substrate resulted in a decrease in the deposition rate with increasing surface coverage. Higher surface coverage of silica nanoparticles was obtained at low pH than at high pH conditions, due to reduced electric diffuse double layer repulsion between the silica nanoparticles. The deposition was enhanced at high pH by increasing the concentration of NaCl due to compression of the electric diffuse double layer. In particular, the repulsion between the silica nanoparticles was efficiently screened at a concentration of NaCl higher than 100 mM and thick silica layers could be deposited at pH = 6 and 8.

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pH-dependent surface charging and points of zero charge

Cited by 312 publications

References 18 publications

Structures and Charging of α-Alumina (0001)/Water Interfaces Studied by Sum-Frequency Vibrational Spectroscopy

Structures and Charging of α-Alumina (0001)/Water Interfaces Studied by Sum-Frequency Vibrational Spectroscopy

Fundamentals in Colloid Science

Deposition of silica nanoparticles onto alumina measured by optical reflectometry and quartz crystal microbalance with dissipation techniques

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