scholarly journals Sepiolite functionalized with N-[3-(trimethoxysilyl)propyl]-ethylenediamine triacetic acid trisodium salt. Part I: Preparation and characterization

2015 ◽  
Vol 80 (9) ◽  
pp. 1193-1202
Author(s):  
Slavica Lazarevic ◽  
Ivona Jankovic-Castvan ◽  
Bojan Jokic ◽  
Djordje Janackovic ◽  
Rada Petrovic
Keyword(s):  
Thermal Analyses ◽  
Morphological Characteristics ◽  
Basic Structure ◽  
Xrd Analysis ◽  
Point Of Zero Charge ◽  
Zero Charge ◽  
Covalent Grafting ◽  
Dta Analysis ◽  
Trisodium Salt

Natural sepiolite from Andrici (Serbia) was functionalized by covalent grafting of N-[3-(trimethoxysilyl)propyl]ethylenediamine triacetic acid trisodium salt to the Si-OH sepiolite groups. The functionalized material, MSEAS, was characterized by determination of phase composition by X-ray diffraction (XRD) analysis, analysis of morphological characteristics by scanning electron microscopy (SEM), using Fourier transform infrared (FTIR) spectroscopy, differential thermal analyses (DTA), determination of specific surface areas and pore size distribution using B.E.T. method and point of zero charge (pHpzc) determination. The crystal structure of sepiolite does not change significantly upon surface modification. FT-IR and DTA analysis confirmed that the modified sample maintained the basic structure of sepiolite and also the presence of organic groups in functionalized sepiolite sample. The point of zero charge of MSEAS in KNO3 solutions of different concentrations determination by the batch technique from was at pH 7.0 ? 0.1.

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

scholarly journals Influence of organic cations sorption on the point of zero charge of natural zeolite

2009 ◽  
Vol 63 (4) ◽  
pp. 325-330 ◽  
Author(s):  
Milan Kragovic ◽  
Aleksandra Dakovic ◽  
Sonja Milicevic ◽  
Zivko Sekulic ◽  
Slobodan Milonjic
Keyword(s):  
Ion Exchange ◽  
Natural Zeolite ◽  
Point Of Zero Charge ◽  
Organic Cations ◽  
Ammonium Ions ◽  
Inorganic Cations ◽  
Ph Values ◽  
Zero Charge ◽  
Basic Characteristics

In this paper, the results of the surface modification of natural zeolite with different amounts (2, 5 and 10 mmol M+/100g) of octadecyldimethylbenzyl ammonium ions (ODMBA) are presented. The obtained organozeolites were denoted as OZ-2, OZ-5 and OZ-10. The degree of ion exchange was followed by determination of amounts of inorganic cations released from zeolite. Results confirmed that reaction between ODMBA and starting zeolite has occurred via ion exchange mechanism. The obtained value for point of zero charge, pHpzc, of natural zeolite was 6.8?0.1, while for OZ-2, OZ-5 and OZ-10 pHpzc was 7.0?0.1. Below the pHpzc, the surfaces of materials are positive while at pH values higher than pHpzc their surfaces are negative. Compared to the pHpzc of natural zeolite, no significant differences in pHpzc was observed for all three organozeolites indicating that obtained products have similar functional groups with similar acid and basic characteristics as starting zeolite. The pHpzc was not dependent on the amount of ODMBA ions at the zeolitic surface and the value of pHpzc for all investigated sorbents is the same for all three electrolyte concentrations indicating that the pHpzc of each material is independent of the ionic strength of KNO3.

Determination of point of zero charge of natural organic materials

2018 ◽  
Vol 25 (8) ◽  
pp. 7823-7833 ◽  
Author(s):  
Elisee Nsimba Bakatula ◽  
Dominique Richard ◽  
Carmen Mihaela Neculita ◽  
Gerald J. Zagury
Keyword(s):  
Organic Materials ◽  
Point Of Zero Charge ◽  
Zero Charge
Sign in / Sign up

Export Citation Format

Share Document