• Elastomers and Composites
• /
• v.44 no.2
• /
• pp.143-149
• /
• 2009

In this study, asphalt emulsion was manufactured by phase inversion emulsification method with nonionic surfactants(Span 80, Span 60, Tween 80, and Tween 60), anionic surfactant(SLS) and cationic surfactant(Imidazole) in different feeding ratio to make up for the week points of asphalt. Its stabilization was carefully investigated with respect to droplet size, viscosity, zeta potential, and water-proofing property. When the surfactants mixed with nonionic and anionic surfactant were used into the asphalt, a stabilization of the asphalt emulsion was good. As the amount of the mixed surfactant was increased, the droplet size of asphalt emulsion were decreased, while the viscosity and zeta potential were increased. When the surfactants mixed with nonionic and anionic surfactant were used into the asphalt, a stabilization of asphalt emulsion was good.

• Journal of Adhesion and Interface
• /
• v.15 no.3
• /
• pp.93-99
• /
• 2014

Monodisperse poly[styrene-co-(COPS-I)] latices in the size range of 165~550nm were successfully prepared by soap-free emulsion polymerization with various polymerization conditions (Styrene, COPS-I, KPS, DVB concentrations and polymerization temperature). In general, the COPS-I and KPS, DVB concentrations and polymerization temperature were closely related to the polymerization rate and the number of particles, molecular weight, and zeta potential. The polymerization rate and zeta potential increased, but molecular weight decreased, with increasing in the number of particles.

• Journal of Adhesion and Interface
• /
• v.13 no.3
• /
• pp.109-115
• /
• 2012

Monodisperse blue-colored poly(styrene-co-acrylic acid) latices were successfully prepared by seeded emulsion polymerization. Blue-colored latices with carboxyl anionic charge on the surface were synthesized at the second stage with the introduction of Blue 606 dye, acrylic acid, and 0.21 ${\mu}m$-polystyrene seed. All the blue-colored latices synthesized in this study were in the size range of 0.25~0.42 ${\mu}m$ and all uniform with less than 1.01 in PSD. The particle size increased with the addition of acrylic acid being delayed and colloidally stable latices were obtained over 30 min after its addition. The blue-colored latex with 20 wt% acrylic acid showed -145 mV of zeta-potential and $-9.4{\times}10^{-6}\;cm^2/Vs$ of electrophoretic mobility, and with 25 wt% of DVB showed high $T_g$ at 396.7 K.

• Korean Journal of Materials Research
• /
• v.11 no.8
• /
• pp.679-684
• /
• 2001

The surface of natural graphite has not only good electrical conductivities and lubrication properties but also has strong hydrophobicity. There are no functional groups and chemical properties on it. It is difficult to join with any other ions and to disperse in aqueous system. In order to increase dispersion ability throughout modification of surface property, it is necessary to let graphite have some function on its surface by the adsorption of surfactant molecules. In this study, using zeta potential adsorbed surfactant molecules(ABDM) on graphite surface and its surface Properties turn hydrophobic into hydrophilic. The dispersing mechanism of graphite particles in aqueous system has been explained using the DLVO theory, It is concluded that the high dispersable graphite suspension of which dispersing stability$(T_{1/2})$ is 44.5 hours at pH 10 and 22.5mV zeta potential can be produced.

• Applied Chemistry for Engineering
• /
• v.9 no.4
• /
• pp.569-573
• /
• 1998

A water soluble polymer, polycondensate of 1-butylamine and epichlorohydrin (PBE), was synthesized by condensation of 1-butylamine and epichlorohydrin. The characteristics of PBE were determined by IR spectroscopy, low angle light scattering measurement, and $\zeta$ potential measurement. Its interactions with colloidal bentonite particles in aqueous medium were also studied. The results of the studies are as follows : PBE is a cationic polyelectrolyte carrying tertiary ammonium ions on its backbone. The average molecular weight of PBE is found to be about 1,600. The adsorption of PBE on the colloidal bentonite particles are well described with Langmuir adsorption isotherm. As the amounts of PBE adsorbed on the bentonite particles increase, the $\zeta$ potential of the particles changes its sign from negative to positive. This inversion of charge confirms that PBE is cationic in nature. The adsorption of PBE onto the bentonite particles was found to occur through cation exchange reaction. It has been shown that PBE has flocculation effects on the colloidal suspension of bentonite. It has also enhanced effects of filtrability on the digested sludge.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.33 no.5
• /
• pp.187-190
• /
• 2023

In this study, antibacterial glasses were developed by the addition of CaO in ZnO-Na₂O-B₂O₃-SiO₂ glass system. The effect of the addition of CaO on the thermal properties, dissolution properties, surface zeta potential and antibacterial activity were analyzed. Differential thermal analysis (DTA) analysis was performed to analyze the thermophysical properties of 30ZnO-xCaO-20Na₂O-30B₂O₃-(20-x)SiO₂ (x = 0, 2, 4, 6, 8, 10 mol%). It was confirmed that the glass transition temperature decreased as the CaO content increased. The amount of released Zn²⁺ ions and surface zeta potential of glass samples increased with increasing CaO concentration. For these reasons, the antibacterial activity was dramatically improved. By the addition of CaO, we could successfully develop an antibacterial glass with 99.9 % antibacterial activity against both Escherichia coli and Staphylococcus aureus.

• Journal of the Korean Ceramic Society
• /
• v.39 no.1
• /
• pp.38-44
• /
• 2002

Dispersion stability of nano-sized rutile TiO$_2$powder with acicular typed primary particle produced by homogeneous precipitation process at low temperatures was studied in aqueous and non-aqueous media in the presence of various electrolytes. The zeta potential measurements have shown that the addition of electrolytes to aqueous and non-aqueous dispersion media leads to charge reversal on TiO$_2$particle surface. The electrostatic repulsive forces acting on between TiO$_2$particles dispersed in non-aqueous media were found to be significantly greater than that in aqueous media, which relate closely to the physical properties of the organic solvents, such as viscosities and dielectric constants. The pH values, the concentration of electrolytes and the valence of the ions have changed greatly the surface potential of TiO$_2$ particles and have governed the dispersion behavior of TiO$_2$particles virtually.

• Journal of Korean Society of Water and Wastewater
• /
• v.18 no.5
• /
• pp.608-618
• /
• 2004

Since polyelectrolytes have been used as conditioners, conventionally only a single polyelectrolyte has been added for sludge conditioning. However, the amount of polyelectrolyte needed for optimal conditioning of sludge is very critical. Overdosing reduces the sludge dewaterbility. In this experimental study, sludge conditioning with single or dual polyelectrolyte was conducted to avoid problems associated with overdosing. Single polyelectrolyte conditioning was conducted by one of cationic, nonionic, and anionic polyelectrolytes. The dual polyelectrolyte conditioning was performed by adding one polyelectrolyte and another one in sequence. The dewaterbility of sludges were measured by SRF(specific resistance to filtration), TTF(time to filter), CST(capillary suction time) respectively. Additionally, parameters such as turbidity, zeta potential, viscosity of conditioned sludges or supematant were measured to evaluate the changed characteristics of sludge by addition of polyelectrolytes. From the experiment results, it was concluded that single polyelectrolyte conditioning had a high probability of overdosing, whereas dual polyelectrolyte conditioning resulted in a better dewaterbility and less chance of overdosing. But, it was also found that dosing sequence in dual conditioning was very important according to the characteristics of sludge. Parameters such as viscosity, turbidity, zeta potential were found to be useful as a means of evaluating sludge dewaterbility.

• Journal of Korean Society of Water and Wastewater
• /
• v.21 no.6
• /
• pp.709-715
• /
• 2007

The dewaterability of a sludge can be characterized by two ways: the residual moisture content in the sludge cake after dewatering process, and the filtration of the sludge. Time to filter (TTF) represents filtration processes that are special cases of the flow through a solid matrix concept. TTF characterizes a resistance to filtration. The sludge resistance, in turn, can be subdivided into resistances associated with the solid phase and the liquid phase to evaluate the effect of each of the two phases on sludge dewaterability. In order to determine the dewatering characteristics of the water sludge samples, TTF and zeta potential were measured. For these studies cationic polymer was chosen for water sludge dewatering experiments. The zeta potential of thickener sludges neared from minus values to zero values till 4 days after sampling. The dewaterability of thickener sludges using cationic polymer was deteriorated according to the increase of detention time. As the detention time was increased from 4 to 10 days, the optimal dose of the polymer was increased from 4 to 8mg/L. Therefore, the optimal detention time plays an important part for the dewaterability of a sludge.

• Journal of Korean Society of Water and Wastewater
• /
• v.22 no.6
• /
• pp.689-696
• /
• 2008

In a water treatment process a complete and homogeneous dispersion of the coagulants in the raw water could be most important factor. This research was performed to evaluate coagulation performance of the in-line-orifice mixer which was recently introduced as a rapid mixing device. The test was to determine the actual coagulant dispersion distribution on the overall cross-section at a distance of 1.6~3D from the chemical injection point by measuring zeta potential. From the results of zeta potential test, it was shown that the coagulant dispersion within the in-line orifice mixer was occurred very unevenly. The results have confirmed that it is necessary to increase the velocity of coagulants injection or pressurized water rates, in order to reduce nonuniform distribution of chemicals.