scholarly journals Influence of Piezoelectric Properties on the Ultrasonic Dispersion of TiO2 Nanoparticles in Aqueous Suspension

Micromachines ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 52
Author(s):  
Seon Ae Hwangbo ◽  
Young Min Choi ◽  
Tae Geol Lee
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Lead Zirconate Titanate ◽  
Aqueous Suspension ◽  
Lead Zirconate ◽  
Ultrasonic Dispersion ◽  
Dispersion Of Nanoparticles ◽  
Hard Type

In this study, the soft-type and hard-type lead zirconate titanate (PZT) ceramics were compared in order to create an optimal system for ultrasonic dispersion of nanoparticles, and sound pressure energy for each PZT ceramic was analyzed and closely examined with ultrasonic energy. TiO2 was water-dispersed using the soft-type and hard-type PZT transducer, possessing different characteristics, and its suspension particle size and distribution, polydispersity index (PDI), zeta potential, and dispersion were evaluated for 180 days. Furthermore, it was confirmed that the particles dispersed using the hard-type PZT transducer were smaller than the particles dispersed using the soft-type PZT by 15 nm or more. Because the hard-type PZT transducer had a lower PDI, uniform particle size distribution was also confirmed. In addition, by measuring the zeta potential over time, it was found that the hard-type PZT transducer has higher dispersion safety. In addition, it was confirmed that the ultrasonically dispersed TiO2 suspension using a hard-type PZT transducer maintained constant particle size distribution for 180 days, whereas the suspension from the soft-type PZT aggregated 30 days later. Therefore, the hard-type PZT is more suitable for ultrasonic dispersion of nanoparticles.

Effect of Dispersant on the Measurement of Particle Size Distribution of Titanium Dioxide

2012 ◽  
Vol 512-515 ◽  
pp. 261-264
Author(s):  
Li Shen ◽  
Jin Hu ◽  
Da Ping Wu
Keyword(s):  
Particle Size ◽  
Titanium Dioxide ◽  
Zeta Potential ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Anionic Surfactant ◽  
Sodium Sulfate ◽  
Aqueous Media ◽  
Rutile Tio2 ◽  
Tio2 Particles

As anionic surfactant, a commercial salt of lauryl sodium sulfate was used. The effects of different amounts of dispersant on the measurement of particle size distribution between two titanium dioxide powders (anatase and rutile) in aqueous media were discussed. Diluted aqueous suspensions were characterized in terms of particle size distribution and zeta potential. The results demonstrate that the measurement of particle size distribution strongly depends on the amounts of dispersant. The amounts of dispersant have a significant effect on the behavior of the rutile-TiO2 particles. The particle size first decreases significantly with an increase in the amounts of dispersant and then lesser increases with a further increase in the amounts of dispersant. The tendency show significant differences between two particles.

Tape Casting of BaTiO3

1984 ◽  
Vol 40 ◽  
Author(s):  
J. B. Blum ◽  
W. R. Cannon
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Glass Plate ◽  
Tape Casting ◽  
Phosphate Ester ◽  
Powder Particle Size ◽  
Drying Method ◽  
Ultrasonic Dispersion ◽  
The Past

AbstractFor the past two years we have been investigating the tape casting of BaTiO3 Specifically we have been interested in developing a useful tape casting formulation and procedure and in studying the effects of powder particle size distribution and dispersion processes on the forming of BaTiO3 tapes.The formulation we have developed is non-aqueous. An MEKethanol mixture is the solvent and an acrylic binder is used. Two dispersants are being used, a phosphate ester and Menhaden fish oil. Ultrasonic dispersion was found to be effective in breaking up weak powder agglomerates. We have found it important to add the dispersant before adding other organic components to obtain the best dispersion and strongest tapes. The drying method is also important to tape strength. The strongest tapes resulted when the tape was removed from the glass plate soon after casting. We have also demonstrated that for forming purposes a wide particle size distribution is preferred.

Removal of clay and blue-green algae particles through zeta potential and particle size distribution in the dissolved air flotation process

2006 ◽  
Vol 6 (1) ◽  
pp. 95-103 ◽  
Author(s):  
D.H. Kwak ◽  
S.J. Kim ◽  
H.J. Jung ◽  
C.H. Won ◽  
S.B. Kwon ◽  
...  
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Green Algae ◽  
Dissolved Air Flotation ◽  
Flotation Process ◽  
Clay Particles ◽  
Blue Green Algae ◽  
Dissolved Air

The raw water characteristics of a water treatment plant in Korea are mainly dependent on two major factors: the clay particles attributed to rainfall and blue-green algae in reservoirs. In this work, zeta potential and particle size distributions of clay and algae particles, which are the important parameters affecting their removal efficiency, were measured to investigate the behavior and removal characteristics of particles under various conditions. The results showed that the zeta potential of blue-green algae was more sensitive to treatment conditions than clay, and it fluctuated highly with coagulant dosage, suggesting that the control of zeta potential is important for effective removal of algae particles. On the other hand, the range of particle size distribution that remained from the preliminary sedimentation tank was generally smaller than for flotation. However, the zeta potential of the remaining particles was either close to the isoelectric point or positive, and the particles were not so hard to remove for that reason. In the final analysis, for simultaneous removal of clay and algae particles, a sufficient zeta potential difference must be formed not only for algae particles but also for small clay particles from the sedimentation tank in the dissolved air flotation process.

The Influence of Groundwater on the Stability of Silica Colloids

2009 ◽  
Vol 1193 ◽  
Author(s):  
Pirkko Holtta ◽  
Mari Lahtinen ◽  
Martti Hakanen ◽  
Jukka Lehto ◽  
Piia Juhola
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Colloidal Silica ◽  
Silica Sol ◽  
Low Salinity ◽  
Silica Concentration ◽  
Silica Colloids ◽  
The Stability

AbstractNon-cementitious grouts have been tested in Olkiluoto for the sealing of fractures with the small hydraulic apertures. A promising non-cementitious inorganic grout material for sealing the fractures with the apertures less than 0.05 mm is commercial colloidal silica called silica sol. The potential relevance of colloid-mediated radionuclide transport is highly dependent on their stability in different geochemical environments. The objective of this work was to follow stability of silica sol colloids in low salinity Allard and saline OLSO reference groundwater (pH 7–11) and in deionized milliQ water. Stability of silica sol colloids was followed by measuring particle size distribution, zeta potential, colloidal and reactive silica concentrations. The particle size distributions were determined applying the dynamic light scattering (DLS) method and zeta potential based on dynamic electrophoretic mobility. The colloidal silica concentration was calculated from DLS measurements applying a calibration using a standard series of silica sol. Dissolved reactive silica concentration was determined using the molybdate blue (MoO4) method.These results confirmed that the stability of silica colloids dependent significantly on groundwater salinity. In deionized water, particle size distribution and zeta potential was rather stable except the most diluted solution. In low salinity Allard, particle size distribution was rather constant and the mean particle diameter remained less than 100 nm. High negative zeta potential values indicated the existence of stable silica colloids. In saline OLSO, particle size distribution was wide from a nanometer scale to thousands of nanometers. The disappearance of large particles, decrease in colloidal particle concentration and zeta potential near zero suggest flocculation or coagulation. Under prevailing saline groundwater conditions in Olkiluoto silica colloids released from silica sol are expected to be instable but the possible influence of low salinity glacial melt water has to be considered.

scholarly journals Determination of Critical Parameters of Drug Substance Influencing Dissolution: A Case Study

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Erika Bojnanska ◽  
Michal Kalina ◽  
Ladislav Parizek ◽  
Eva Bartonickova ◽  
Tomas Opravil ◽  
...  
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Particle Size Distribution ◽  
Dissolution Rate ◽  
Size Distribution ◽  
Drug Product ◽  
Drug Formulation ◽  
Drug Substance ◽  
Critical Parameters ◽  
Dissolution Profile

The purpose of this study was to specify critical parameters (physicochemical characteristics) of drug substance that can affect dissolution profile/dissolution rate of the final drug product manufactured by validated procedure from various batches of the same drug substance received from different suppliers. The target was to design a sufficiently robust drug substance specification allowing to obtain a satisfactory drug product. For this reason, five batches of the drug substance and five samples of the final peroral drug products were analysed with the use of solid state analysis methods on the bulk level. Besides polymorphism, particle size distribution, surface area, zeta potential, and water content were identified as important parameters, and the zeta potential and the particle size distribution of the drug substance seem to be critical quality attributes affecting the dissolution rate of the drug substance released from the final peroral drug formulation.

scholarly journals Characterization of kaolin dispersion using acoustic and electroacoustic spectroscopy

2008 ◽  
Vol 44 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Z. Dohnalová ◽  
L. Svoboda ◽  
P. Sulcová
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Divalent Cations ◽  
Dispersing Agent ◽  
Time Period ◽  
Ultrasonic Techniques

The objective of this work is the investigation of the kaolin dispersion by the ultrasonic techniques. In contact with aqueous solution clay minerals show cation - exchange properties and certain degree of dissolution or rather selective leaching of components. The work is divided into two main parts - determination of zeta potential and particle size distribution. The first part is focused on measuring of zeta potential. Effects of concentration of solid, different kind of electrolytes (0.01 M KCl, 0.01 M MgCl2 and 0.01 M CaCl2), pH and temperature of the dispersions are investigated. The isoelectric points (IEP) of kaolin suspension are about pH 4-5. Electrolytes containing monovalent cations such as K+ become zeta potential more negative compared to the values obtained with water. Such behavior is explained by the exchange of K+ ions with H+ ions in the system. When the electrolyte is formed by divalent cations such as Mg2+ or Ca2+, the values of zeta potential become less negative than zeta potential of kaolin in water. The second part is focused on the determination of particle size distribution with respect to dispersing conditions, such as the optimal dispersing agent (Na2SiO3, (NaPO3)6, Na4P2O7 or Busperse), time and power of ultrasonication and also the tracking of dispersion stability that is expressed by the measuring of particle size distribution during certain time period.

Evaluation of Physical Properties and Antibacterial Activity of Bioactive Compounds-Loaded Chitosan Nanoparticles

2018 ◽  
Vol 936 ◽  
pp. 3-7 ◽  
Author(s):  
Zormy Nacary Correa-Pacheco ◽  
Silvia Bautista-Baños ◽  
Mónica Hernández-López ◽  
María Luisa Corona-Rangel
Keyword(s):  
Particle Size ◽  
Antibacterial Activity ◽  
Essential Oil ◽  
Zeta Potential ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Bioactive Compounds ◽  
Chitosan Nanoparticles ◽  
Ethanol Extract ◽  
Byrsonima Crassifolia

Bioactive compounds such as essential oils (EO), botanical extracts and natural resins are well known to have beneficial properties. Among these properties are their antibacterial activity. A disadvantage of these compounds is that they are volatile. Therefore, encapsulation is a good way to overcome this problem. In this study, the morphology, particle size distribution, Zeta potential and microbiological activity of chitosan nanoparticles incorporated with three different bioactive compounds having antimicrobial properties: ethanol extract of propolis, thyme essential oil and ethanol extract of Byrsonima crassifolia (L.) Kunth were evaluated. Nanoparticles were synthesized using the nanoprecipitation method. The morphology was observed using transmission electron microscopy (TEM). Also, particle size distribution and Zeta potential were measured. Results show spherical in shape nanoparticles. Thyme essential oil-loaded chitosan nanoparticles (TEO-CSNPs) showed the smallest particle size and highest stability as assessed by Zeta potential measurement, followed in stability by ethanol extract of propolis-loaded chitosan nanoparticles (EEP-CSNPs), ethanol extract of Byrsonima crassifolia (L.) Kunth (EEBC-CSNPs) and finally by chitosan nanoparticles (CSNPs). The antibacterial activity of the bioactive compounds-loaded chitosan nanoparticles was evaluated against Staphylococcus aureus. The highest antibacterial activity was observed for TEO-CSNPs with an inhibition halo (IH) value of 10.54±0.78 mm, followed by EEP-CSNPs (8.10±1.19 mm). EEBC-CSNPs and CSNPs did not show zone of inhibition. Bioactive compounds-loaded chitosan nanoparticles represents a good alternative for bacterial control of food borne pathogens in applications for fruits and vegetables conservation.

Sign in / Sign up

Export Citation Format

Share Document