Determination of the point of zero charge, surface acidity constants, and relative concentration of the charged surface groups of γ-aluminas used as carriers

Langmuir ◽  
1986 ◽  
Vol 2 (3) ◽  
pp. 281-283 ◽  
Author(s):  
L. Vordonis ◽  
P. G. Koutsoukos ◽  
A. Lycourghiotis
Keyword(s):  
Relative Concentration ◽  
Surface Acidity ◽  
Point Of Zero Charge ◽  
Surface Groups ◽  
Charged Surface ◽  
Acidity Constants ◽  
Zero Charge

scholarly journals Temperature Effect on the Surface Properties of ZnO(am)

1997 ◽  
Vol 15 (10) ◽  
pp. 789-802 ◽  
Author(s):  
S. Mustafa ◽  
Shahida Parveen ◽  
Aftab Ahmad ◽  
Dilara Begum
Keyword(s):  
Zinc Oxide ◽  
Temperature Effect ◽  
Thermodynamic Parameters ◽  
Dissociation Constants ◽  
Surface Acidity ◽  
Point Of Zero Charge ◽  
Acidity Constants ◽  
Zero Charge ◽  
Increasing Temperature ◽  
Thomas Equation

The point of zero charge and surface acidity constants of zinc oxide were determined over the temperature range 293–323 K. Both the point of zero charge (pzc) and the surface acidity constants (pKa1 and pKa2) were found to decrease with increasing temperature. The values of the dissociation constants (pKa1 and pKa2) determined from the Henderson-Hasselbach equation agreed very well with those determined using the Gaines-Thomas equation. The thermodynamic parameters ΔH0 and ΔS0 for the processes were also evaluated.

scholarly journals Determination of Point of Zero Charge (PZC) of Concrete Particles Adsorbents

2021 ◽  
Vol 1184 (1) ◽  
pp. 012004
Author(s):  
Ebtehal A. Al-Maliky ◽  
Hatem A. Gzar ◽  
Mohammed G. Al-Azawy
Keyword(s):  
Point Of Zero Charge ◽  
Zero Charge

scholarly journals Determination of the Point of Zero Charge pH of Borosilicate Glass Surface Using Capillary Imbibition Method

2017 ◽  
Vol 9 (3) ◽  
pp. 67 ◽  
Author(s):  
Mumuni Amadu ◽  
Adango Miadonye
Keyword(s):  
Aqueous Solution ◽  
Free Energy ◽  
Borosilicate Glass ◽  
Present Method ◽  
Interfacial Free Energy ◽  
Point Of Zero Charge ◽  
Oxide Surface ◽  
Colloid Chemistry ◽  
Zero Charge

The point of zero charge pH of an oxide surface is a fundamental surface chemistry property or solids or metal oxides that determine the nature of interaction at the solid-aqueous solution interface. In colloid chemistry this physical parameter controls the evolution of the electric double layer as well as adsorption and desorption processes.In colloid chemistry a number of methods have been used for the determination of the point of zero charge pH of an oxide surface. This ranges from titrimetric to radiation chemistry approach that deals with scanning electron microscopy.In this study, the direct effect of aqueous solution acidity on the solid-liquid interfacial free energy and the consequence of this effect on spontaneous imbibition of aqueous solution into borosilicate glass have been exploited for the determination of the point of zero charge pH of this type of glass. What is new in this method is that while the traditional titration method relies on neutralization of surface charges, the present method relies on interfacial free energy changes due to aqueous solution pH changes and the effect of this on the wettability of borosilcate glass surface. Result of point of zero charge pH obtained from the present method has been compared with those obtained using traditional methods. The comparison shows close agreements and this proves the technique used in the present work as a novel method for the determination of the point of zero charge pH of oxide surfaces.

DETERMINATION OF POINTS OF ZERO CHARGE OF NATURAL AND TREATED ADSORBENTS

2007 ◽  
Vol 14 (03) ◽  
pp. 461-469 ◽  
Author(s):  
M. NASIRUDDIN KHAN ◽  
ANILA SARWAR
Keyword(s):  
Particle Size ◽  
Ph Dependence ◽  
Exchange Capacity ◽  
Point Of Zero Charge ◽  
Surface Charges ◽  
Ion Exchange Capacity ◽  
Zero Charge ◽  
Wide Range ◽  
Acid And Base

Although particle size and its measurement are intuitively familiar to particle technologists, the concept of point of zero charge (pzc) is less widely understood and applied. This is unfortunate since it is at least as fundamentally important as particle size in determining the behavior of particulate materials, especially those with sizes in the colloidal range below a micrometer. pzc is related to the charge on the surface of the particle and strongly depends on the pH of the material; so it influences a wide range of properties of colloidal materials, such as their stability, interaction with electrolytes, suspension rheology, and ion exchange capacity. The pH dependence of surface charges was quantified for four different adsorbent–aqueous solution interfaces. The points of zero charge were determined for activated charcoal, granite sand, lakhra coal, and ground corn cob materials using three methods: (1) the pH drift method, measuring pH where the adsorbent behaves as a neutral specie; (2) potentiometric titration, measuring the adsorption of H + and OH - on surfaces in solutions of varying ionic strengths; (3) direct assessment of the surface charge via nonspecific ion adsorption as a function of pH. The intrinsic acidity constants for acid and base equilibria, [Formula: see text] and [Formula: see text], were also calculated. Lakhra coal was found to have the lowest pzc value among all other adsorbents studied owing to the presence of a large amount of humus material. The results were used to explain general connections among points of zero charges, cation exchange capacity, and base saturation % of adsorbents.

Suitability of Two Methods for Determination of Point of Zero Charge (PZC) of Adsorbents in Soils

2015 ◽  
Vol 47 (1) ◽  
pp. 101-111 ◽  
Author(s):  
Michael K. Miyittah ◽  
Francis W. Tsyawo ◽  
Kingsley K. Kumah ◽  
Craig D. Stanley ◽  
Jack E. Rechcigl
Keyword(s):  
Point Of Zero Charge ◽  
Zero Charge
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