Zeta potential of membranes as a function of pH Optimization of isoelectric point evaluation

2003 ◽  
Vol 213 (1-2) ◽  
pp. 225-230 ◽  
Author(s):  
A Martín
Keyword(s):  
Zeta Potential ◽  
Isoelectric Point ◽  
Point Evaluation ◽  
Ph Optimization

Electrokinetic Potential for Characterization of Nanosctructured Solid Flat Surfaces

2013 ◽  
Vol 25 ◽  
pp. 31-39 ◽  
Author(s):  
Zdeňka Kolská ◽  
Nikola Slepičková Kasálková ◽  
Jakub Siegel ◽  
Václav Švorčík
Keyword(s):  
Zeta Potential ◽  
Isoelectric Point ◽  
Electrokinetic Potential ◽  
Characteristic Parameter ◽  
Metal Nanostructures ◽  
Gold Deposition ◽  
Fast Analysis ◽  
Flat Surfaces ◽  
Acceptable Method ◽  
Point Determination

Electrokinetic potential (zeta potential) is a characteristic parameter for description of the surface chemistry of solid flat materials and it can be used for a fast analysis of materials modified by different chemical or physical methods. Due to its sensitivity, zeta potential is able to distinguish surface modified by coating with monolayers of various materials or nanostructures created after plasma treatment. Also metal nanostructures deposited on surfaces can be characterized by zeta potential. It can also be used for isoelectric point determination of materials. We present data on zeta potential in 0.001 mol/dm3 KCl at constant pH7.0 and also in pH range (2.5-7.0) for isoelectric point determination for pristine polymers PET, PTFE, PS, LDPE, HDPE, PLLA, PVF, PVDF, PMP and polyimides (Upilex R, Upilex S, Kapton). The zeta potential of selected polymers, modified by plasma and by chemical coatings (e.g. by biphenyldithiol or polyethyleneglycol) or by gold deposition was measured too. Zeta potentials of these modified materials were also studied to confirmation that electrokinetic analysis is acceptable method for their fast description.

scholarly journals Compost leachate treatment using polyaluminium chloride and nanofiltration

2017 ◽  
Vol 15 (1) ◽  
pp. 123-128 ◽  
Author(s):  
Marjana Simonič
Keyword(s):  
Zeta Potential ◽  
Isoelectric Point ◽  
Oxygen Demand ◽  
Treatment Method ◽  
Aluminium Chloride ◽  
Leachate Treatment ◽  
Physico Chemical ◽  
Pre Treatment ◽  
Ph Range ◽  
Compost Leachate

AbstractLaboratory scale filtration tests utilizing leachate were conducted to investigate fouling and filtration performance of nanofiltration membranes. The work presented in this study is conducted on real samples rather than model water. Physico-chemical analyses showed that the leachate contained a lot of organic substances, exceeding 20000 mg/L O2 expressed as chemical oxygen demand. Proper pre-treatment method must be chosen in order to reduce fouling index. Coagulation pre-treatment using poly-aluminium chloride was chosen. Two thin film polysulfone membranes were used, purchased by Osmonic Desal. The focus of this research is to assess the influence of the particle size and zeta-potential of the colloidal fraction in leachate on nanofiltration performance. The isoelectric point of both membranes was 4.7 and 4.3, respectively. The fouled membranes were negatively charged over the pH range with isoelectric point shifting to the left (lower pH) indicating the foulant material mainly not charged. It was confirmed by its zeta-potential, measured at -2 mV.

Formation mechanism of spherical oxide particles containing dye

1999 ◽  
Vol 14 (5) ◽  
pp. 2088-2091
Author(s):  
Sixin Wu ◽  
Congshan Zhu
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Formation Mechanism ◽  
Isoelectric Point ◽  
Sol Gel ◽  
Diameter Distribution ◽  
Maximum Particle Size ◽  
Maximum Particle ◽  
Oxide Particles ◽  
Positively Charged

2-[3-(1,3-dihydro-1,3,3-trimethyl-2H-indol-2-ylidine)-1-propenyl]-1,3,3-trimethyl-3H-indolium idoide (HICI) dye-doped SiO2 particles were synthesized by sol-gel method. Dimension, diameter, distribution, and homogeneity of the particles are closely related to the positively charged dye concentration, corresponding to the zeta potential of the particles. When the dye concentration reaches about 7.8 × 10−4 mol/mol SiO2, corresponding to the isoelectric point of the particles, the maximum particle size and the most homogeneity can be reached.

scholarly journals Zeta Potential, Effective Membrane Charge and Donnan Potential for TiO2 NF Ceramic Membrane

2018 ◽  
Vol 24 (9) ◽  
pp. 21 ◽  
Author(s):  
Ahmed Faiq Hassan Al-Alawy ◽  
Amer Naji Ahmed Al-Naemi ◽  
Mudhaffar Yacoub Hussein
Keyword(s):  
Zeta Potential ◽  
Charge Density ◽  
Surface Charge ◽  
Isoelectric Point ◽  
Pore Radius ◽  
Ceramic Membrane ◽  
Effective Thickness ◽  
Donnan Potential ◽  
Membrane Charge ◽  
Effective Pore Radius

Nanofiltration (NF) ceramic membrane have found increasing applications particularly in wastewater and water treatment. In order to estimate and optimize the performance of NF membranes, the membrane should be characterized correctly in terms of their basic parameters such as effective pore radius (rp) and equivalent effective thickness as well as effective surface charge ( ), the effective charge density ( ) and Donnan potential ( ). The impact of electrokinetic (zeta) potential on the membrane surface charge density, effective membrane charge density and Donnan potential at two different concentrations of the reference solutions 0.001, 0.01 M sodium chloride at various pH values from 3 to 9, and effective pore radius (rp) for nominal 0.9 nm  ceramic TiO2 NF membrane were evaluated. Experiments were conducted at cross flow (1.0 m/s) using Microelectrophoresis technique for measuring membrane zeta potential, effective pore radius, and Donnan steric pore model (DSPM). The TiO2 membrane isoelectric point (net membrane charge equals zero) was found at pH of 3.7, 3.5 for 0.001 and 0.01 M NaCl respectively. The results showed that the NF membrane zeta potential changes its sign from positive to negative after the isoelectric point. The evaluated effective pore radius was found to be equal to 0.56 nm by using (DSPM) and the membrane equivalent effective thickness equals to (2×10-6 m).  

scholarly journals Electrokinetic properties of chemically modified jute fabrics

2020 ◽  
pp. 69-69
Author(s):  
Aleksandra Ivanovska ◽  
Mirjana Kostic
Keyword(s):  
Zeta Potential ◽  
Isoelectric Point ◽  
Carboxyl Groups ◽  
Chemical Modifications ◽  
Electrokinetic Properties ◽  
Chemically Modified ◽  
Ph Values ◽  
Electrochemical Double Layer ◽  
Jute Fabrics ◽  
Oxidatively Modified

This work aims to study the alkali and oxidatively modified jute fabrics? electrokinetic properties. In contrast to control fabric, chemically modified jute fabrics have a small positive zeta potential in a basic pH range which can be attributed to the presence of sodium cations (originating from mentioned chemical modifications) on their surfaces. At lower pH values, samples modified under milder alkali and oxidative conditions have about 2.2-3.5 times lower zeta potential since the protonation process leads to the formation of higher positive charge in the electrochemical double layer causing higher adsorption of Cl- ions (originating from the electrolyte). On the other hand, more intensive chemical modifications increased the zeta potential at lower pH values due to the increased amount of carboxyl groups and fibers? ability for water retention and hence swelling. The isoelectric point of fabrics having lower zeta potential than control fabric was shifted toward higher pH values pointing out lower contribution of fabrics? surface acidic groups. In the case of extensive oxidation conditions (60 and 90 min), the isoelectric point was shifted toward lower pH values as a result of lignina removal and mentioned higher availability of newly formed carboxyl groups.

Study on Zeta Potential of Micron-Size Tourmaline Powders

2013 ◽  
Vol 785-786 ◽  
pp. 395-399
Author(s):  
Xiao Hui Zhang ◽  
Rui Hua Wu
Keyword(s):  
Zeta Potential ◽  
Isoelectric Point ◽  
Neutral Condition ◽  
Reducing Conditions ◽  
Heat Treated ◽  
Micron Size ◽  
Laser Granulometer ◽  
Acid Range

Zeta potential of micron-size tourmaline powders are studied using the laser granulometer and the Zeta potential analyzer. The result from the experiment shows, in the neutral condition, the micron-size tourmaline is negatively charged under water and Elbaite powder has the highest Zeta potential among all tested ones; the smaller the tourmaline powder is, the higher Zeta potential it has; heat-treated samples under reducing conditions have higher Zeta potential than those under oxidizing conditions by 4~5 mV; Dravites isoelectric point is 3.4, falling within the acid range.

The zeta potential of kaolin suspensions measured by electrophoresis and electroacoustics

2007 ◽  
Vol 61 (2) ◽  
Author(s):  
R. Greenwood ◽  
B. Lapčíková ◽  
M. Surýnek ◽  
K. Waters ◽  
L. Lapčík
Keyword(s):  
Zeta Potential ◽  
Isoelectric Point ◽  
Anionic Surfactant ◽  
Sodium Dodecyl ◽  
Isomorphic Substitution ◽  
Concentrated Suspensions ◽  
Concentrated Suspension ◽  
Zeta Potentials ◽  
Maximum Value ◽  
Triton X

AbstractThe zeta potentials of kaolin dilute and concentrated suspensions were monitored using the techniques of electrophoresis and electroacoustics, respectively. The effect of addition of salt (KCl), a polymer material (Triton X-100), and an anionic surfactant (sodium dodecyl sulphate, SDS) on the suspension properties was investigated by electrophoresis. Electroacoustics was employed for the measurement of zeta potentials for the highest possible kaolin content in suspension and the effect of dilution. The effect of aging of a freshly prepared sample and kaolin isoelectric point was also studied. Using both techniques it was noted that there was no isoelectric point, just a maximum value in the magnitude of the kaolin suspension zeta potential. These maxima were observed also in the presence of Triton X-100 and SDS. An increase of the concentration of KCl and SDS in suspension shifted the maxima towards more acidic values, while in the presence of Triton X-100 the position of the zeta potential maxima remained constant. Electroacoustic techniques revealed that a freshly prepared concentrated suspension requires about six hours to equilibrate to achieve a steady zeta potential. Diluting the concentrated suspensions led to decrease of the zeta potential as ions bound to the surface desorbed and screened the surface charge. The zeta potential maxima remained unchanged even after heating the powder in an oven at 200°C (to remove any organic material) thereby suggesting that the most likely explanation for the maxima is isomorphic substitution.

Zeta Potential of Stable Oxidative Poly-Si-Fe (SOPSF) Coagulant

2012 ◽  
Vol 518-523 ◽  
pp. 150-153
Author(s):  
Ying Fu ◽  
Nan Shi ◽  
Hong Lan Li
Keyword(s):  
Zeta Potential ◽  
Isoelectric Point ◽  
Polysilicic Acid ◽  
Zeta Potentials

Characteristics of Zeta potential of a stable oxidative poly-Si-Fe (SOPSF) coagulant was studied with Nano Zetasizer, in comparison with that of polyferric aluminum (PFA). The results showed that the reaction between polysilicic acid (PS) negative charged and Fe positive charged is complicated, instead of a simple electro neutrality process. The Zeta potentials of SOPSF are almost near to the isoelectric point at higher concentration, while the Zeta potential of PFA is about 20 times that of SOPSF carrying negative charges at the same concentration. But after dilution, the Zeta potential of SOPSF is about equivalent to that of PFA.

Agglomerate formation during drying

2003 ◽  
Vol 18 (2) ◽  
pp. 495-506 ◽  
Author(s):  
Alejandro Vertanessian ◽  
Andrew Allen ◽  
Merrilea J. Mayo
Keyword(s):  
Zeta Potential ◽  
Isoelectric Point ◽  
Direct Consequence ◽  
Ph Values ◽  
Diffusion Limited ◽  
X Ray Scattering ◽  
Primary Particles ◽  
Small Primary ◽  
Ph Range ◽  
Size Scales

The evolution of agglomerate structure during drying of particles from suspension has been studied for a nanocrystalline Y2O3 (8% mol fraction)-stabilized ZrO2 powder. Agglomerates in drying and dried suspensions were examined at the smallest size scales (1 nm to 1 μm) using ultra-small angle x-ray scattering (USAXS) and at the largest size scales (100 nm to 10 μm) using scanning electron microscopy. The results were correlated with the degree of particle dissolution in each suspension (measured by flame absorption spectroscopy of the suspension filtrate) and the zeta potential of the particles in suspension prior to drying. Results show that large agglomerates readily form across a pH range from 2 to 9. The fact that Y+3 ion dissolution varies by over four orders of magnitude in this range leads to the conclusion that there is little direct correlation between the degree of Y dissolution and agglomeration in this system (Zr ion dissolution was below the detection limit at all pH values studied). The observation of large agglomerates well before the introduction of air-water interfaces into the drying mass likewise leads to the conclusion that capillary forces are not essential to agglomerate formation. Instead, agglomerates appear to form as a direct consequence of increasing suspension concentration. Zeta potential also plays a role. Specifically, there was a notable change in agglomerate morphology as the isoelectric point was approached, at approximately pH 8. Here USAXS shows the particles in suspension to have a layered interior structure, with small primary particles aggregated in sheets to form each blocky particle. This is in contrast to the more rounded agglomerates formed away from the isoelectric point, which appear to be composed of the same primary particles arranged in chainlike structures. USAXS of powders from the dried suspensions confirms that the structures seen after drying are the same as those present in suspension. The two structural morphologies are attributed to diffusion-limited (sheets) versus reaction-limited (chains) aggregation, respectively.

Sign in / Sign up

Export Citation Format

Share Document