• Journal of the Korean Ceramic Society
• /
• v.40 no.3
• /
• pp.293-300
• /
• 2003

It was investigated that effect of suspension and electrolyte concentrations on zeta potential of alumini suspension and Iso-Electric Point(I.E.P.). The alumina powders in 0.1∼l $\mu\textrm{m}$ particle size distribution, and the electrolyte NH$_4$NO$_3$ were used for preparing the suspension and electrophoresis method was used for measuring zeta potential in this work. As the concentration of suspension was increased, zeta potential and the I.E.P. were increased, respectively. On the other hand, as the electrolyte concentration was increased, the I.E.P. was decreased. As a result of this work, the best condition for measuring zeta potential was the 0.01 wt% and 10 mM of the suspension and the electrolyte concentration, respectively.

• Korean Chemical Engineering Research
• /
• v.53 no.6
• /
• pp.831-835
• /
• 2015

This study evaluated the influence of the zeta potential of silica-alumina on the behavior in terms of purity, yield, and precipitate shape and size of fractional precipitation in the fractional precipitation process for the purification of (+)-dihydromyricetin. The optimal silica-alumina amount (surface area per working volume of reacting solution) for zeta potential control was $100mm^{-1}$. As the zeta potential value of silica-alumina increased, (+)-dihydromyricetin yield and precipitate size were increased. The use of silica with the highest value of the zeta potential (+4.99 mV) as a zeta potential-controlling material increased the (+)-dihydromyricetin yield by 2-fold compared with that of the use of alumina with the lowest value of the zeta potential (-19.00 mV). In addition, the (+)-dihydromyricetin yield and precipitate size was inversely correlated with the absolute value of the zeta potential. On the other hand, the purity of (+)-dihydromyricetin had almost no effect on changes in the zeta potential of silica-alumina.

• Microbiology and Biotechnology Letters
• /
• v.42 no.2
• /
• pp.114-120
• /
• 2014

This study evaluated the effect of the zeta potential of silica-alumina on the behavior, in terms of purity, yield, fractional precipitation time, precipitate shape, size of fractional precipitation in the increased surface area, and the fractional precipitation process, for the purification of paclitaxel. As the zeta potential value of silica-alumina increased, the yield of paclitaxel concurrently increased while the precipitation time decreased. The use of alumina with the highest value of the zeta potential (+35.41 mV) as a surface area-increasing material dramatically reduced the precipitation time by 12 h compared with the results of the control. On the other hand, the purity of paclitaxel had almost no effect on changes in the zeta potential of silica-alumina. In addition, the precipitate size was inversely correlated with the absolute value of the zeta potential.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.33 no.2
• /
• pp.105-110
• /
• 2007

The stability of titanium dioxide dispersion was evaluated by zeta ($\zeta$) potential and we intended to apply it for improvement of dispersion stability. Both theories related to $\zeta$ potential (electric double layer, electrophoresis, isoelectric point and electroosmosis) and a method to measure $\zeta$ potential were explained in this study. The change in $\zeta$ potential of $TiO_2$ dispersion was measured by means of Henry's function of Helmholtz-Smoluchowski's equation (H-S equation). The $\zeta$ potentials of $TiO_2$ dispersion were negative in all measured pH values ($3.0{\sim}9.0$), and absolute values of $\zeta$ potentials of $TiO_2$ increased as pH values increased. $TiO_2$ dispersion was maintained in pH 8.0 and 9.0 respectively. From these results, we suggest that $\zeta$ potentials have an effect on $TiO_2$ dispersion and absolute value of $\zeta$ potentials played an important role in the stability of $TiO_2$ dispersion in aqeous medium.

• Membrane Journal
• /
• v.27 no.5
• /
• pp.399-405
• /
• 2017

The zeta potential, called an electrokinetic potential, refers to the potential difference caused by electrodynamic phenomenon, which is a value obtained by quantifying the surface charge property. The zeta potential has been actively studied for membrane fouling, confirmation of modification and substituent confirmation through surface charge analysis. The methods of measurement for zeta potential were developed on the basis of electrophoresis, electrosmosis and streaming potential. Among them, it was known that the streaming potential method was suitable for the flat sheet membrane. So, in this study, aminated poly(styrene-ethylene-butylene-styrene) membranes were prepared by introducing ammonium groups and the streaming potentials of the prepared membranes were measured by using an electrokinetic potential analyzer (SurPASS) and the results were analyzed.

• Ceramist
• /
• v.5 no.3
• /
• pp.44-53
• /
• 2002

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2001.05a
• /
• pp.54-54
• /
• 2001

• Journal of Korean Society of Water and Wastewater
• /
• v.18 no.5
• /
• pp.573-579
• /
• 2004

Electroflotation, which is used as an alternative to sedimentation, is a separation treatment process that uses small bubbles to remove low-density particulates. Making allowances for recent collision efficiency diagram based on trajectory analysis, it is necessary to tailor zeta potential of bubbles that collide with negatively charged particles. In this paper, the study was performed to investigate the effects of magnesium and aluminium ions on zeta potential of bubbles. And, it was studied to find out factors which could affect the positively charged bubbles. Consequently, zeta potential of bubbles increased both with higher concentration of metal ions and in the acidic pH value. And, a probable principle that explained the procedure of charge reversal could be a combined mechanism with both specific adsorption of hydroxylated species and laying down of hydroxide precipitate. It also depended on the metal ion concentration in the solution to display its capacity to control the bubble surface.

• Journal of the Korean Ceramic Society
• /
• v.38 no.7
• /
• pp.654-659
• /
• 2001

고령토 슬러리의 분산특성에 미치는 양이온성 polyethyleneimine 결합제의 영향을 고찰하였다. 분산제인 Sodium Hexametaphosphate (SHP)를 0.8 wt% 첨가한 경우와 첨가하지 않은 두 가지 슬러리 내에서 polyethyleneimine (PEI)의 첨가량에 따른 슬러리의 응집, 분산거동을 점도 및 제타전위 측정을 통해 평가하였다. 슬러리 내에 SHP 유무에 상관없이 PEI 농도가 0.02 wt%일 경우에는 응집, 0.6 wt%에서는 분산, 0.6 wt% 이상에서는 재응집되는 것으로 각각 나타났다. 슬러리가 응집-분산-재응집과정을 거치는 동안 점토입자의 제타전위는 항상 일정한 값을 유지하였다. 또한 입자표면의 PEI의 흡착량은 SHP를 첨가한 슬러리의 경우가 크게 나타났으며, 분산성은 상대적으로 더 향상됨을 알 수 있었다.

• Journal of Korean Society of Water and Wastewater
• /
• v.23 no.3
• /
• pp.353-362
• /
• 2009

A new method and equipment for measuring the zeta potential of the external surface of hollow fiber (HF) membranes is reported. An existing commercial streaming potential analyzer in conjunction with home-made test cells was used to determine the electrokinetic surface characteristics of various HF membranes. It was shown that measurements of the external surface of HF membrane using the home-made test cells designed in this study were easy and reliable. The zeta potential values were quite accurate and reproducible. By varying the physical shape of the test cells to adjust hydrodynamics inside the test cells, several upgrade versions of home-made test cells were obtained. It was shown that the zeta potential of the external surface of HF membranes was most influenced by membrane materials as well as the way of surface modification. However, the overall surface charge of tested HF membranes were much less than that of commercial polyamide thin-film-composite (TFC) reverse osmosis (RO) membranes due to the lack of surface functional groups. For the HF membranes with the same material, the effect of pore size on the zeta potential was not significant, implying the potential of accurate zeta potential measurements for various HF membranes. The results obtained in this study are expected to be useful for better understating of electrokinetic surface characteristics of the external surface of HF membranes.