scholarly journals Effect of Tris and acetic acid on the stability of titania nanoparticles in different alcohols and their electrophoretic deposition process

2018 ◽  
Vol 12 (1) ◽  
pp. 56-65 ◽  
Author(s):  
Morteza Farrokhi-Rad
Keyword(s):  
Acetic Acid ◽  
Zeta Potential ◽  
Electrophoretic Deposition ◽  
Colloidal Stability ◽  
Optimum Concentration ◽  
Titania Nanoparticles ◽  
Potential Measurement ◽  
The Stability ◽  
Kinetics Of ◽  
Titania Coating

Tris (tris(hydroxymethyl)aminomethane) was used as the dispersant to enhance the colloidal stability of titania nanoparticles in different alcohols (methanol, ethanol, isopropanol and butanol). Acetic acid (AA) was also used to increase the ionization of Tris via acid-base reaction. The effect of Tris on the stability of suspensions in the absence as well as the presence of AA was investigated by different analysis, such as conductivity and zeta potential measurement as well as FTIR analysis. It was found that Tris is protonated and adsorbed on the titania nanoparticles. It enhances their zeta potential and thus colloidal stability. The optimum concentration of Tris increased with molecular weight of alcohol (0.1, 0.2, 0.3 and 0.6 g/l for methanolic, ethanolic, isopropanolic and butanolic suspensions, respectively). The optimum concentration of Tris decreased to 0.1 g/ l for all AA containing suspensions except the methanolic ones. Titania coating was obtained by electrophoretic deposition (EPD) performed at 60 V. The current density and in-situ kinetics of deposition were recorded during EPD. It was found that the kinetics of EPD is the fastest for the suspensions with the optimum concentration of Tris (the highest zeta potential). Calcium phosphate phases were formed on the surface of titania coating after its immersion for one week in SBF at 37.5?C.

Thin Films of Europium (III) Doped-TiO2 Prepared by Electrophoretic Deposition from Nanoparticulate Sols

2012 ◽  
Vol 507 ◽  
pp. 73-77 ◽  
Author(s):  
Mario Borlaf ◽  
Maria Teresa Colomer ◽  
Howard Titzel ◽  
James H. Dickerson ◽  
Rodrigo Moreno
Keyword(s):  
Thin Films ◽  
Zeta Potential ◽  
Electrophoretic Deposition ◽  
Colloidal Stability ◽  
Sol Gel ◽  
Complete Characterization ◽  
Constant Current ◽  
Molar Ratio ◽  
Versatile Technique ◽  
The Stability

Colloidal sol-gel is a common method used for the preparation of stable and homogeneous sols and thin films. The nanoparticulate sols can be easily deposited by EPD, which is a versatile technique for producing denser and thicker coatings than those produced by other techniques like dipping. A complete characterization of the sols, such as colloidal stability and electrophoretic mobility, which can be determined through zeta potential measurements, as well as the influence of deflocculants in the surface properties, is needed before using electrophoretic deposition. In this work, we have prepared sols of TiO2with an alkoxide:water molar ratio of 50:1 and Eu (III) doped-TiO2(2 mole % Eu (III)) using as precursors titanium (IV) isopropoxide and europium (III) acetate hydrate, respectively. The stability of the particulate sols was studied in terms of conductivity, zeta potential and viscosity evolution. Anatase stable sols, after peptization and without the use of any additive, were deposited on stainless steel substrates by electrophoretic deposition under both constant current and constant voltage conditions. Using different intensities and deposition times we have obtained thin films with different features (thicknesses and morphology) and different optical properties. The presence of europium (III) increases particle size, viscosity and peptization time and decreases the band gap of TiO2.

scholarly journals Stability studies of hybrid TiO2 based nanofluids

2021 ◽  
Vol 5 (1) ◽  
pp. 37-45
Author(s):  
Radhiyah Abd Aziz ◽  
Wong Sze Yin
Keyword(s):  
Zeta Potential ◽  
Weight Fraction ◽  
Carbon Powder ◽  
Hybrid Nanofluid ◽  
Sonication Time ◽  
Potential Measurement ◽  
Zeta Potential Measurement ◽  
Ultrasonication Time ◽  
The Stability ◽  
Triton X

This article studies the stability of hybrid TiO2 based nanofluid by varying the ultra-sonication time, weight fraction between carbon and TiO2 and type of surfactant. The objective of this research are synthesise volume fraction of 0.1% C - TiO2 hybrid nanofluid with 15ml of distilled water and study the effect of weight fraction between C and TiO2, type of surfactant and ultra-sonication time to the stability of hybrid nanofluid. Weight fraction between C – TiO2 will be varied at 0% - 100%, 10% - 90%, 50% - 50%, 90% - 10% and 100% - 0%. Different ultrasonication time will be used which are 1, 3 and 5 hours to determine the optimum ultrasonication time for the hybrid nanofluid. Sodium dodecyl sulphate (SDS) and Triton X-100 will be added into hybrid nanofluid to determine the effect of surfactant to the stability of hybrid nanofluid. The morphology and particle size characteristic of TiO2 and carbon powder is evaluated by using X-ray diffraction and FESEM. It is shown that TiO2 has particle size of around 30nm while carbon powder used is flat shaped. In this research, two steps method is used to synthesise the hybrid nanofluid. After mixing the two powder together, it will be mixed with distilled water by magnetic stirring for 3 hours. Then ultrasonication is included in synthesise of hybrid nanofluid to prevent agglomeration of particles. The pH values of each hybrid nanofluid is measured by using pH meter. Two stability evaluations are carried out which are centrifugation and zeta potential measurement. Centrifugation is carried out right after hybrid nanofluid is done ultra-sonicated for 30 minutes at 2000 RPM. Hybrid nanofluid that is ultra-sonicated for 3 hours resulted to achieve highest stability with highest value of zeta potential of -21.8 mV. 100% C - 0% TiO2 hybrid nanofluid has the highest zeta potential measurement of -37.6 mV. Finally, for type of surfactant, SDS able to enhance stability of hybrid nanofluid more than Triton X-100. The zeta potential of hybrid nanofluid after addition of SDS reached -47.0 mV which is higher than Triton X-100 which only achieve zeta potential measurement of -24.3 mV.

scholarly journals Characterization and Nanofluid Stability of CoFe2O4-APTES and CoFe2O4-PVA Nanoparticles

2020 ◽  
Vol 78 (1) ◽  
pp. 79-87
Author(s):  
Anis Arisa Roslan ◽  
Hasnah Mohd Zaid ◽  
Siti Nur Azella Zaine ◽  
Mursyidah Umar ◽  
Beh Hoe Guan
Keyword(s):  
Surface Modification ◽  
Zeta Potential ◽  
Performance Studies ◽  
Colloidal Stability ◽  
Amino Silane ◽  
Cobalt Iron Oxide ◽  
One Step ◽  
The Stability ◽  
Surface Modified ◽  
Surface Modified Nanoparticles

Nanofluid contains nanoparticles that enhanced the property of the base fluid. However, the separating layer between the nanoparticles and base fluids may interfere the nanofluids performance. Studies have been made that surface modification of nanoparticles may improve the dispersion of nanoparticles in base fluids. This paper reports the study of the colloidal stability of surface modified nanoparticles using a polymer and an amino-silane. The nanoparticles were prepared by one-step and two-step methods using cobalt iron oxide nanoparticles with brine solution and deionized water as the base fluids. Functionalization by surface modification of the nanoparticles to enhance the nanofluids stability was carried out using (3-aminopropyl) triethoxysilane (APTES) and polyvinyl alcohol (PVA). Characterization using Fourier Transform Infrared (FTIR), Field Emission Scanning Electron Microscope (FESEM) and X-ray Powder Diffraction (XRD) were performed to study the functionality and morphology of the synthesized nanoparticles. The extra IR peaks such as Si-O-Si at 1063 cm-1 for CoFe2O4-APTES and C=O at 1742 cm-1 for CoFe2O4-PVA showed that there are additional elements in the cobalt ferrite due to functionalization. The size of synthesized CoFe2O4-APTES ranged between 15.99 nm to 26.89 nm while CoFe2O4-PVA is from 25.70 nm to 54.16 nm. The stability of the nanofluid were determined via zeta potential measurements. CoFe2O4-APTES nanofluid has zeta potential of -35.7 mV compared to CoFe2O4-PVA at -15.5 mV.

Triethanolamine as an Additive in the Electrophoretic Deposition of TiTe3O8 Thick Films

2012 ◽  
Vol 507 ◽  
pp. 27-34
Author(s):  
Xin Ming Su ◽  
Ai Ying Wu ◽  
Paula M. Vilarinho
Keyword(s):  
Zeta Potential ◽  
Electrophoretic Deposition ◽  
Uv Light ◽  
Thick Films ◽  
Solid State Reaction Method ◽  
Conventional Solid State Reaction ◽  
Si Substrates ◽  
Improved Stability ◽  
The Stability

A successful electrophoretic deposition (EPD) markedly depends on the stability of the suspension. In this study the role of Triethanolamine (TEA) as a stabilizer in EPD of thick films of TiTe3O8 is presented. TiTe3O8 powders were synthesized via a conventional solid-state-reaction method and dispersed in acetone with and without TEA. The stability of the suspensions was addressed by zeta-potential, UV light and FTIR measurements. The specific adsorption of TEA to TiTe3O8 particles results in a high zeta potential and improved stability of the suspensions, allowing the preparation of high quality TiTe3O8 thick films on Pt coated Si substrates. TiTe3O8 films sintered at 700 °C are dense and homogeneous.

Aqueous Colloidal Stability Evaluated by Zeta Potential Measurement and Resultant TiO2 for Superior Photovoltaic Performance

2013 ◽  
Vol 96 (8) ◽  
pp. 2636-2643 ◽  
Author(s):  
Fargol Hasani Bijarbooneh ◽  
Yue Zhao ◽  
Jung Ho Kim ◽  
Ziqi Sun ◽  
Victor Malgras ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Colloidal Stability ◽  
Photovoltaic Performance ◽  
Potential Measurement ◽  
Zeta Potential Measurement

scholarly journals Nanomagnetit-bentonit vizes közegű diszperz rendszereinek zeta-potenciáljának vizsgálata

2021 ◽  
Vol 6 (4) ◽  
Author(s):  
Ákos Pintér-Móricz ◽  
Renáta Dr. Zákányiné Dr. Mészáros
Keyword(s):  
Zeta Potential ◽  
Surface Properties ◽  
Colloidal Stability ◽  
Salt Content ◽  
Fluid Loss ◽  
Drilling Process ◽  
Hybrid Particles ◽  
The Stability ◽  
Application Fields ◽  
Drilling Muds

The stability of different type nanomaterials play an important role among recent scientific and industrial challenges, including the examination of the effect of polymers, surfactants and their mixture on surface and electric surface properties and aggregation extent of dispersed particles, which are of utmost importance. Bentonite and its composite with different nanomaterials are frequently used for instance in environmental protection for wastewater treatment, since due to their great specific surface area they have excellent sorption properties. There are several publications in the literature for the application of bentonite in drilling muds. By using them the fluid loss can be decreased during the drilling process, the filtration of the fluid can be increased, it also improves the rheological properties and the formation damage can also be mitigated. During research the investigation and the analysis of the zeta-potential of nanoparticles and their composites at different pH and salt content can be an interesting topic. During our experiments the electric surface properties of nanomagnetite synthetized in laboratory (NM), cation exchanged bentonite from Mád (Be) and the composite particles of these particles were investigated. Hybrid particles of different compositions (9:1, 7:3, 1:1, 3:7, 1:9) were analyzed at different potassium chloride concentrations (0.1 – 0.0001 M). The surface adsorption on the surface, i.e. the change in the surface charge can be traced well by analyzing the obtained zeta-potential values. The behavior of such systems was observed in the full pH interval, thus, valuable data were obtained regarding the colloidal stability. As for the stability, different requirements may emerge in practice, there are application fields where the colloidally stable system is advantageous, on the other hand, in some cases, ceasing the stabile system is the goal. Our investigations are of high importance in terms of stability and its characterization [1].

Stability of Suspensions and Emulsions Containing Illitic Clays

2016 ◽  
Vol 721 ◽  
pp. 337-342 ◽  
Author(s):  
Inga Jurgelane ◽  
Agnese Stunda-Zujeva ◽  
Liga Berzina-Cimdina
Keyword(s):  
Zeta Potential ◽  
Clay Minerals ◽  
Colloidal Particles ◽  
Colloidal Stability ◽  
Safflower Oil ◽  
Iron Compounds ◽  
Oil In Water ◽  
Increasing Demand ◽  
The Stability

There are a lot of studies about colloidal stability of suspensions and emulsions containing clay minerals, but only few about illite containing clays. Due to increasing demand for eco cosmetics, research about the possibility to use natural colloidal particles (clay minerals) as stabilizers also increases. In this study illitic clays were used to investigate the stability of glycerol containing suspensions and safflower oil-in-water emulsions. Three types of clay samples were used – chemically untreated, after removal of carbonates and iron compounds. Viscosity and zeta potential of glycerol suspensions was determined. Samples with the highest viscosity were also the most stable. The removal of iron compounds significantly decreased the viscosity of suspensions and increased the zeta potential

Electrophoretic Deposition of Natural Hydroxyapatite

2009 ◽  
Vol 412 ◽  
pp. 183-188
Author(s):  
Mehdi Javidi ◽  
Sirus Javadpour ◽  
Mohammad Ebrahim Bahrololoom ◽  
Jan Ma
Keyword(s):  
Zeta Potential ◽  
Electrophoretic Deposition ◽  
Applied Voltage ◽  
Deposition Time ◽  
316L Stainless Steel ◽  
Deposition Process ◽  
Dispersing Agent ◽  
Coating Efficiency ◽  
The Stability ◽  
Natural Hydroxyapatite

Natural hydroxyapatite has been electrophoretically deposited on medical grade 316L stainless steel. Stable suspensions were prepared by mixing 40 g/L milled natural hydroxyapatite powder in isopropyl alcohol and stabilized by polyethylenimine as dispersing agent and binder. The stability of suspensions was investigated by measuring zeta potential. It was found here that the suspension which was stabilized with 4 g/L polyethylenimine revealed a high value of zeta potential and stability. Deposition was achieved on the cathode at constant voltages of 30, 60, and 90 V for 1 to 5 minutes. After deposition, the samples were dried at room temperature for 24 hours and deposition weight, roughness, and thickness of the coatings were measured. The surface morphology of the coated samples was studied by a scanning electron microscope. The results of the electrophoretic deposition process showed that the sample coated at 60 V and 3 minutes led to an adherent, continuous, and crack-free coating. The coating efficiency and thickness increased with increasing deposition time and yielded to saturation at the constant applied voltage. Also, the current density decreased and yielded to saturation at the constant applied voltage during electrophoretic deposition.

Facile real-time evaluation of the stability of surface charge under regular shear stress by pulsed streaming potential measurement

RSC Advances ◽  
2015 ◽  
Vol 5 (96) ◽  
pp. 78519-78525 ◽  
Author(s):  
Lei Zhao ◽  
Xianglu Peng ◽  
Shenghong Yang ◽  
Yuan Zhang ◽  
Jing Wu ◽  
...  
Keyword(s):  
Shear Stress ◽  
Zeta Potential ◽  
Surface Charge ◽  
Real Time ◽  
Streaming Potential ◽  
Potential Change ◽  
Potential Measurement ◽  
Change Rate ◽  
The Stability ◽  
Time Evaluation

The applicability of the pulsed streaming potential measurement for real-time evaluation of stability of assembled layers based on the relative zeta potential change rate SR was demonstrated.

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