• Journal of the Korean Ceramic Society
• /
• v.28 no.2
• /
• pp.146-152
• /
• 1991

Ultra fine and homogeneous (Ni0.4Zn0.6)Fe2O4 ferrite powders were prepared by direct-wet, Hydrothermal and coprecipitation methods. In case that specific surface areas of Ni-Zn ferrite powders were over 220㎡/g, 100㎡/g, 30㎡/g individually direct-wet, hydrothermal and coprecipitation methods. The Ni-Zn ferrite magnetic fluids of which Solvents were benzene or kerosene was prepared by making cation surfactant adsorbed on the surface of the (Ni0.4Zn0.6)Fe2O4. The results that measured dispersion and viscosity by making cation surfactant adsorbed were as follows. 1. The adsorption amount of Oleric acid be proportioned the specific surface area of powders. 2. The maximum amount of Oleric acid was 36wt% of dried powders which has 220㎡/g of specific surface area. 3. The stability of fluid by direct-wet synthesis emthod in benzene or kerosene solvent excellent.

• Journal of Soil and Groundwater Environment
• /
• v.11 no.2
• /
• pp.1-12
• /
• 2006

A model describing the distributions of surfactants and HOCs (hydrophobic organic chemicals) in surfactant/HOC/activated carbon systems for surfactant reuse in soil washing process was developed. The model simulation was conducted for the evaluation of the effect of concentrations of surfactant, HOC, or activated carbons. Phenanthrene as a target HOC, Triton X-100 as surfactant and three granular activated carbons with different particle sizes (4-12, 12-20, and 20-40 mesh) were used in the model simulation. The distributions of HOC were significantly affected by surfactant dosages, especially at around the CMC(s). The results of selectivities for phenanthrene were much larger than 1 at various concentrations of surfactants, phenanthrene and activated carbons, which mean that the selective adsorption of phenanthrene by activated carbons is a proper separation method from surfactant solution. The model can be applied for the design of the surfactant reuse process using activated carbons without extra experimental efforts.

• Journal of Soil and Groundwater Environment
• /
• v.13 no.2
• /
• pp.1-11
• /
• 2008

Phenanthrene uptake by surfactant sorbed on activated carbon was investigated to recycle of surfactant in washed solution for contaminated soil. The partitioning of phenanthrene to the activated carbon coating with Triton X-100 as a surfactant was also evaluated by a mathematical model. Phenanthrene-contaminated soil (200 mg/kg) was washed in 10 g/L of surfactant solution. Washed phenanthrene in solution was separated by various particle loadings of granular activated carbon through a mode of selective adsorption. Removal of phenanthrene was 99.3%, and surfactant recovery was 88.9% by 2.5 g/L of granular activated carbon, respectively. Phenanthrene uptake by activated carbon was greater than that of phenanthrene calculated by a standard model for a system with one partitioning component. This is accounted for enhanced surface solubilization by hemi-micelles adsorbed onto granular activated carbon. The effectiveness factor is greater than 1 and molar ratio of solubilization to sorbed surfactant is higher than that of liquid surfactant. Results suggest that separation of contaminants and surfactants by activated carbon through washing process in soil is much effective than that of calculated in a theoretical model.

• Applied Chemistry for Engineering
• /
• v.24 no.1
• /
• pp.24-30
• /
• 2013

The adsorption characteristics of cationic starches and starch-oligomers were investigated using the quartz crystal microbalance with dissipation monitoring (QCM-D). The adsorbed amount of modified starches was higher than that of cationic surfactants such as $C_{12{\sim}16}$ trimethylammonium bromide. Cationic starches did not show the tendency depending on the degree of cationic substitution and molecular weight. On the other hand, the softness of the adsorption layer increased with the molecular weight of cationic starches in a viscoelasticity terms. During the adsorption/desorption steps, the amount of adsorbed cationic surfactants was 4~9 times. On the other hand, the difference in the amount of adsorption of all the $C_1$ grafted cationic starches was just 0~50%. In addition, the rigidity of the adsorption layer of cationic surfactant in the desorption step decreased, while, that of cationic starches increased at the same condition.

• Journal of Soil and Groundwater Environment
• /
• v.13 no.1
• /
• pp.32-42
• /
• 2008

A surfactant recovery and reuse process by selective adsorption with activated carbon was proposed to reduce surfactant cost in a soil washing process. Mathematical model simulation was performed for the whole process, which consists of soil washing, soil recovery, and soil re-washing. The optimal range of surfactant dosage was $6{\sim}10$-fold critical micelle concentration in soil. The efficiency of surfactant reuse process was decreased with increasing the dosage of activated carbon. Effectiveness factor for activated carbon significantly altered the efficiency of the reuse process unlike effectiveness factor for soil. Total requirement of surfactant was reduced to 20-30% with the reuse process compared to the conventional soil washing process. The contamination of wastewater after soil washing was reduced with the reuse process. This mathematical model can be used to estimate performance of the whole process of soil washing including surfactant recovery and to obtain optimal ranges of operating conditions without extra labor-intensive experimental works.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.45 no.2
• /
• pp.105-116
• /
• 2019

Oil adsorption during hair or body washing is responsible for the hair conditioning. In this study, we established a method to extract oil from a substrate, and to determine amount of adsorbed oil upon substrate using a conventional absorption spectroscopy. We controlled the mole fraction of a surfactant in a mixture of anionic and amphoteric surfactants because that it induces the coacervate that regulates amount of adsorbed oil through the alteration of oil viscosity. Based on this, we established the optimized condition for adsorption and extraction for oil. UV absorbance were employed to estimate the amount of adsorbed oil using optical absorbance after extraction via adsorption. The estimation was confirmed by comparing with a mass analysis in HPLC and an adhesive energy in AFM. It has been proved that this method can be applied to all cases of oil adsorption from the results with various cationic polymers and a complex system of the polymers which regulate the oil adsorption.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.31 no.3
• /
• pp.1-9
• /
• 1999

Effect of furnish on enzyme activity was investigated by using the three components (cellulose, enzyme, and cationic polyelectrolyte) model papermaking system. Avicel was used as a cellulose model compound to observe the effect of adsorption and desorption of enzyme with other component and the resultant change of particle size. As an experimental result, the enzyme loses considerably its apparent activity due to the adsorption onto cellulose and cationic polyelectrolyte. Activities of enzyme applied to the actual papermaking stocks having controlled fiber length showed different behavior in terms of pulp species UKP and KOCC stocks. That is, the enzyme activity in UKP was increased as fines content increased, however, vice versa in KOCC stock . This result can be considered to be the existence of various contaminants included in the fines of KOCC . The effect of possible contaminants such as inorganic materials, calcium ion, surfactant, and conductivity on enzyme activity were also investigated.

• Textile Coloration and Finishing
• /
• v.13 no.1
• /
• pp.18-22
• /
• 2001

Effects of cationic surfactants old the wetting behavior of the DMDHEU treated cotton fibers were investigated using a technique based on the Wilhelmy principle. The results indicated that Interactions between the fiber and water ill the interface make contributions to wettability of the cotton fiber surface because of reorientation of polar groups at the interface. The effects of types and concentration of cationic surfactant on the wettability of both control and durable press(DP) finished cotton fiber are discussed. Below and near the critical micelle concentration(cmc), the adsorption of hexadecyltrimethylammoniumbromide(HTAB) on the control fiber makes the fiber surface more hydrophobic. Near and above the cmc of octadecyltrimethylammouniumbromide(OTAB) , the decrease in advancing contact angles indicates that the control cotton surface became hydrophilic. By the adsorption of both HTAB and OTAB onto the fiber surface, the hydrophobicity of the DP finished fiber surface became mere hydrophilic.

• Journal of Industrial and Engineering Chemistry
• /
• v.67
• /
• pp.132-139
• /
• 2018

A cost-effective preparation method is proposed to prepare nanoporous alumina (NA) using aluminum chloride as a precursor with a lower cost than aluminum butoxide. In addition, the surfactant template was replaced with magnesium stearate, which has a lower unit cost in stearate acid. The adsorption isotherm test for the CO gas was carried out to compare the adsorption performance of the NA adsorbents prepared using post-hydrolysis (NA) and cost-effective precipitation (C-NA). In addition, C-NA exhibited a similar uptake capacity as NA, and the maximum uptake capacity of Pd/C-NA increased 1.3 times via Pd nanodots loading.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2005.10a
• /
• pp.169-170
• /
• 2005