Effects of pH and Dispersant Concentration on Properties of Li1.075Nb0.625Ti0.45O3 Aqueous Suspension

2011 ◽  
Vol 266 ◽  
pp. 26-29
Author(s):  
Shao Chun Li ◽  
Yong Juan Geng ◽  
Qi Long Zhang ◽  
Hui Yang
Keyword(s):  
Zeta Potential ◽  
Direct Relationship ◽  
Ph Value ◽  
Aqueous Suspension ◽  
Aqueous Media ◽  
Potential Measurement ◽  
Optimum Ph ◽  
Effects Of Ph ◽  
Rheological Test ◽  
Good Agreement

The dispersion behavior of the solid solution Li1.075Nb0.625Ti0.45O3 (LNT) in aqueous media was studied. Optimum dispersing conditions were investigated in terms of zeta potential, sedimentation, and rheology measurements. Zeta potential measurement showed that the isoelectric point (IEP) of the LNT particles was shifted from pH 3.7 to pH 2.6 after adsorption of PAA-NH4 and made the LNT surface more electronegative. Good agreement between zeta potential, sedimentation, and rheological test was found, which identified an optimum pH value of 10 and an optimum dispersant concentration of about 0.6 wt%. The green microstructures of the casting tapes bear a direct relationship to the state of dispersion of the slurries. The results showed that PAA-NH4 is a suitable dispersant for obtaining well-dispersed LNT slurries.

Fabrication and Characterization of Sr0.7Ca0.3TiO3 Substrates Using Aqueous Tape Casting Process

2010 ◽  
Vol 434-435 ◽  
pp. 275-277
Author(s):  
Wei Liang Liu ◽  
Shuo Qi Liu ◽  
Du Song Mao
Keyword(s):  
Zeta Potential ◽  
Ph Value ◽  
Tape Casting ◽  
Casting Process ◽  
Solid Loading ◽  
Potential Measurement ◽  
Binder Ratio ◽  
Rheological Test ◽  
Test Result

Sr0.7Ca0.3TiO3 (SCT) substrates were prepared through aqueous tape casting. Properties of SCT slurries with and without ammonium polyacrylate (NH4PAA) dispersant were characterized by zeta potential. The zeta potential measurement result shows that the isoelectric point (IEP) of the powder changed obviously with the addition of the dispersant. The optimum pH value of the slurry is in the range of 9-10. The rheological test result indicates that the proper content of the dispersant is between 0.6 and 0.8 wt%. The effect of different plasticizer/binder ratio (R) on the properties of the green tapes was investigated. For 56 wt% solid loading, the tensile strength of the green tape reached 2.02 MPa and the breaking elongation rate was about 8%. SEM micrographs show that the microstructure of the green tapes is homogeneous and the microstructure of the sintered tapes is dense.

A New Operation of Carbohydrate-Containing Wastewater Treatment in an Anaerobic Fluidized Bed System

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2453-2456 ◽  
Author(s):  
A. Matsumoto ◽  
M. Sakamoto ◽  
T. Noike
Keyword(s):  
Anaerobic Digestion ◽  
Fluidized Bed ◽  
Ph Value ◽  
Type Systems ◽  
Growth Type ◽  
Attached Growth ◽  
Optimum Ph ◽  
Effects Of Ph ◽  
Growth System ◽  
Ph Range

The effects of pH on the characteristics of conversion of starch to methane in anaerobic digestion were investigated by using a laboratory-scale anaerobic fluidized bed reactor over the pH range of 5.8-7.0. Furthermore, a new operation method was proposed to treat wastewater containing starch effectively. At pH 6.2, starch was decomposed well and methane was also formed well. The phenomenon showed methanogenesis in an attached growth system developed more tolerance for lower pH than in suspended growth type systems. After all, pH 6.2 was the optimum pH value for conversion of starch tomethane in our experiment. From these results, it is proposed that the more effective anaerobic digestion is made possible by the operation at low pH (for example 6.2) which accelerates acidogenesis and doesn't inhibit methanogenesis in attached growth systems.

scholarly journals Separation of Ga(III) from Cu(II), Ni(II) and Zn(II) in aqueous solution using synthetic polymeric resins

2008 ◽  
Vol 6 (1) ◽  
pp. 39-45 ◽  
Author(s):  
A. Massaoud ◽  
H. Hanafi ◽  
T. Siyam ◽  
Z. Saleh ◽  
F. Ali
Keyword(s):  
Acrylic Acid ◽  
Contact Time ◽  
Ph Value ◽  
Aqueous Media ◽  
Separation Process ◽  
Optimum Ph ◽  
Ethylenediaminetetracetic Acid ◽  
Radiation Induced ◽  
Polymeric Resins ◽  
Poly Acrylamide

AbstractPoly (acrylamide-acrylic acid-dimethylaminoethylmethacrylate), p(AM-AA-DMAEM) and Poly(acrylamide-acrylic acid)-ethylenediaminetetracetic acid disodium, p(AM-AA)-EDTANa2 were prepared by gamma radiation-induced template polymerization technique and used for the separation of Ga (III) from Cu (II), Ni (II), and Zn (II) in aqueous media. The effect of pH and contact time on the separation process was studied. The optimum pH value for the separation process is 3–3.5. The result shows that Ga (III) is first extracted while Cu (II), Ni (II) and Zn(II) are slightly extracted at this pH value. The recovery of metals using HCl, HNO3 and H2SO4 has been studied. The resins may be regenerated using 2M HCl solutions.

Electrokinetic Properties and Their Effect on Thermal Conductivity of Nanofluids

2008 ◽  
Author(s):  
S. M. Sohel Murshed ◽  
Kai Choong Leong ◽  
Chun Yang
Keyword(s):  
Thermal Conductivity ◽  
Zeta Potential ◽  
Effective Thermal Conductivity ◽  
Electrolyte Concentration ◽  
Ph Value ◽  
Deionized Water ◽  
Ph Values ◽  
Nacl Concentration ◽  
Effects Of Ph ◽  
Similar Decrease

This paper presents the effects of pH value, surfactant, and electrolyte concentration on zeta potential and effective thermal conductivity of nanofluids. The zeta potential of TiO2 (15 nm) nanoparticles in deionized water of different pH values was measured and the iso-electrical point was found to be between 4.9 and 5.2. The results show that the higher the electrolyte concentration, the smaller the particle zeta potential, which results in increased agglomeration of particles. The enhanced thermal conductivity of TiO2/deionized water-based nanofluids was found to decrease with increasing pH value or electrolyte concentration. For example, for 0.2 volume %, the thermal conductivity of this nanofluid was found to decrease from 5.5% to 2.5% when the pH value was increased from 3.4 to 9. A similar decrease (≈ 2%) in thermal conductivity was observed when NaCl concentration was increased from 0.01 mM to 10 mM. The presence of a surfactant showed considerably larger enhancement of the effective thermal conductivity compared to that of nanofluids without surfactant.

Predicting struvite formation for phosphorus recovery from human urine using an equilibrium model

2006 ◽  
Vol 54 (8) ◽  
pp. 247-255 ◽  
Author(s):  
H. Harada ◽  
Y. Shimizu ◽  
Y. Miyagoshi ◽  
S. Matsui ◽  
T. Matsuda ◽  
...  
Keyword(s):  
Ionic Strength ◽  
Model Prediction ◽  
Human Urine ◽  
Equilibrium Model ◽  
Ph Value ◽  
Phosphorus Recovery ◽  
Practical Application ◽  
Optimum Ph ◽  
Alkaline Conditions ◽  
Good Agreement

Interest in phosphorus recovery from urine diverted from faeces has been growing recently. Phosphorus in urine can be precipitated out as struvite (MgNH4PO4•6H2O) with addition of magnesium salt under alkaline conditions. Struvite formation, however, should be more well understood for its practical application. We predicted the struvite formation with a development of a new equilibrium model. The model considered the formation of eight different kinds of precipitates, including struvite, with effects of ionic strength and temperature. In addition, experiments on struvite formation in urine were conducted for the model validation. The model prediction of struvite formation had good agreement with the experimental results. The optimum pH to form struvite was predicted to be 9.4–9.7. In order to precipitate 99% of phosphate in urine with 1.5 fold Mg concentration to PO4-P, the pH value was necessary to be more than 8.1 based on the model prediction.

scholarly journals The Effects of Ammonium Polyacrylate and Diammonium Citrate as Base and Acid Dispersion Agents on Yttria-Stabilized Zirconia (3Y-TZP) Dispersion Properties

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Pestaria Sinaga ◽  
Sung-Hwan Bae
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Ph Value ◽  
Aqueous Suspension ◽  
Low Ph ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Attrition Mill ◽  
Shear Rates ◽  
Dispersion Properties

Stable slurries in dispersions of 3Y-TZP in aqueous suspension with the addition of different concentrations of dispersants such as ammonium polyacrylate (APA) and diammonium citrate (DAC) were investigated. The dispersion properties were investigated by measuring the particle size, zeta potential, sedimentation, and viscosity as a function of the wt.% of the dispersant. Both dispersant agents were attached to the 3Y-TZP surface by the carboxylic group, as shown by the FTIR results. The addition of dispersants was found to produce more dispersed and stabilized aqueous suspension. As shown the viscosity result, that there is no being viscosity peak has been occurring and viscosity going decrease as the shear rates increasing which mean that the suspension has shear thinning behavior and there is no agglomeration as the shear rate is increased. It was determined that 3.5 wt.% of DAC and APA produced the best and most stable slurry; when 3.5 wt.% of DAC and APA was added, the zeta potential showed the largest value in the monodisperse condition. The low pH value of DAC has obtained the higher zeta potential value than APA, which was assumed due to low pH of DAC suspension. At low pH, the adsorption of the adsorbate will occur in a flat adsorbed, while at higher pH the polyelectrolyte will dangle into solution, thus reducing electrostatic repulsion as it is found in the case of APA addition. In this condition, the particle size was decreased to the lower value and the slurry’s stability was obtained with the lowest sedimentation height after the sedimentation test for 30 days. The sample was milled in an attrition mill at 1,000 rpm for four hours.

scholarly journals Analysis of the Application Potential of Coffee Oil as an Ilmenite Flotation Collector

Minerals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 505 ◽  
Author(s):  
Wang ◽  
Xiao ◽  
Ma ◽  
Li ◽  
Chen ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Ph Value ◽  
Foam Stability ◽  
Great Influence ◽  
Potential Measurement ◽  
Ilmenite Concentrate ◽  
Foam Properties ◽  
Application Potential ◽  
Coffee Oil ◽  
Flotation Collector

Coffee grounds are the most significant production waste in the coffee industry and contain about 15% coffee oil. Coffee oil is rich in fatty acids and polyphenols, which have great application potential in the flotation of oxidized minerals. In this study, coffee oil as a green flotation collector for ilmenite was investigated by micro-flotation, zeta potential measurement, and foam stability analysis. The results of zeta potential reveal that both coffee oil and MOH can be adsorbed on the ilmenite surface at pH 6.7, and the chemical adsorption mode is dominant. However, when the pH is 2.8, the adsorption capacity of coffee oil on the ilmenite surface is much larger than that of MOH. The pH value of the pulp has little effect on the foam properties in the coffee oil solution and has a great influence on the foaming performance and foam stability of the MOH solution. When coffee oil is used as a collector, the grade of TiO2 in ilmenite concentrate is increased from 21.68% to 46.83%, and the recovery is 90.22%, indicating that the potential of coffee oil in the application of ilmenite flotation is large.

Characterization of Electrokinetic Properties of Nanofluids

2008 ◽  
Vol 8 (11) ◽  
pp. 5966-5971 ◽  
Author(s):  
S. M. Sohel Murshed ◽  
Kai Choong Leong ◽  
Chun Yang
Keyword(s):  
Thermal Conductivity ◽  
Zeta Potential ◽  
Base Fluid ◽  
Electrolyte Concentration ◽  
Ph Value ◽  
Deionized Water ◽  
Hydrodynamic Diameter ◽  
Volume Percentage ◽  
Effects Of Ph

The effects of pH value, surfactant, and electrolyte concentration on zeta potential, particle agglomeration, and thermal conductivity of nanofluids are investigated. The zeta potential of TiO2 (15 nm) nanoparticles in deionized water of different pH values was measured and the iso-electric point was found to be between 4.9 and 5.2. Addition of surfactant in the base fluid increases the zeta potential and thus increases the effective thermal conductivity of nanofluids. The results show that the higher the electrolyte concentration, the smaller the particle zeta potential, which results in increased agglomeration of particles. The enhanced thermal conductivity of TiO2/deionized water-based nanofluids was found to decrease with increasing pH value or electrolyte concentration. At 0.2 volume percentage of TiO2 nanoparticles, the decrease of thermal conductivity of nanofluids was within 2% when the pH value or electrolyte concentration was increased from 3.4 to 9 or 0.01 mM to 10 mM, respectively. The hydrodynamic diameter of agglomerated nanoparticles in base fluid was also measured and found to increase with increasing electrolyte concentration.

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