• Journal of the Korean Society of Marine Environment & Safety
• /
• v.14 no.2
• /
• pp.145-148
• /
• 2008

Cationic surfactant can be used as cosmetics and chemical dispersants. The variation of critical micelle concentration (CMC) with temperature over the range $40^{\circ}C$ to $60^{\circ}C$ for N-octadecyl pyridinium bromide was measured by drop methods. Thermodynamic quantities such as free energy, enthalpy, entropy and heat capacity for micellization of N-octadecyl pyridinium bromide in water were calculated by fourth-degree polynominal equation In the result, free energy change was decreased generally by the increment of temperature.

• Applied Chemistry for Engineering
• /
• v.18 no.5
• /
• pp.490-494
• /
• 2007

Dispersants were prepared from petroleum pyrolysis residual oil (PPRO) through sulfonation. Without employing a conventional polynaphthalene sulfonate formaldehyde condensate (PNS) process, the dispersants (NPS) were synthesized by a simpler process only in 2 h. The chemical structure of new dispersant, which has various naphthalene derivative groups, was similar to PNS conformed by UV-visible spectroscopy curves. The new dispersants demonstrated high dispersing ability in inorganic suspension ; cement, $Fe_2O_3$, and $CaCO_3$.

• Polymer(Korea)
• /
• v.36 no.1
• /
• pp.104-110
• /
• 2012

The dispersion of pigment particles is important because it is capable of increasing the color strength, contrast, and transmittance of color-LCD products. Pigment dispersion properties are very important factors for the quality of LCD color filters. The chemical structure of polymeric dispersants for pigment is important to improve dispersion stability and prevent aggregation or flocculation of pigment in organic or aqueous systems. Polymeric dispersants should contain both anchoring group that interacts with pigment surface and stabilizing group that provides steric stabilization. Moreover, the molecular weight and composition of block copolymer have the an effect on pigment dispersion. In this study, adequate dispersants, block copolymers containing (2-dimethylamino)ethyl methacrylate as anchoring group and oligo(ethylene oxide)methyl ether methacrylate as a stabilizing group were designed and synthesized by atom transfer radical polymerization in order to prepare well-defined structure, molecular weight and composition.

• 한국석유지질학회:학술대회논문집
• /
• autumn
• /
• pp.68-84
• /
• 1999

Biodegradation is a natural weathering process by microorganisms to decompose spilled oil or environmental contaminants. To accelerate this process, applying nutrients (fertilizer) or more microorganisms to naturally occurring microorganisms is called 'Bioremediation.' Presently, most popular response technique to spilled oil is mechanical cleanup using booms or skimmers. For the alternative to this technique, chemical dispersants, in-situ burning are used. Another promising alternative is bioremediation and it can clean oil contaminated seashore during enough time. In this paper, types of bioremediation technologies, its usage potential, and important consideration issues when applying this technique were summarized.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.8 no.1
• /
• pp.139-148
• /
• 2002

As the Busan harbor is getting susceptible to oil Pollution. the authors analyze the historical records of oil spill accidents and investigate the shoreline features. In addition. we evaluate the response capabilities and compute the required stockpiles of marine oil spill response with the worst case scenario in this area. As a result, it is shown that the recommendable oil spill response is to contain and mechanically recover all oils at sea surface in winter. while chemical dispersants can be used in summer with mechanical containment and recovery, and it is also found that off-shore booms of 3,000m and off-shore skimmers of 986MT/hour recovery rate should be stockpiled with 10,000∼60,000 liters of concentrate chemical dispersant and small amount of synthetic organic sorbents for possible use.

• 한국해양학회지
• /
• v.26 no.4
• /
• pp.324-331
• /
• 1991

Laboratory experiments were undertaken in mixing chamber to study the water-in-oil emulsion formation tendency, stability and formation rate of 16 crude oils. Arabian, Iran, Dubai, Isthmus and Daekyung crudes showed high emulsion formation tendency and had water contents of 80-90%. Emulsions of crude oils of middle East were very stable, while Isthmus and Daekyung sudes formed unstable emulsion. Emulsion formation tendency rate, and stability showed significant correlations with asphaltene content of crude oil. To evaluate the possibility of preventing mousse formation, inhibition ability of several dispersants and demulsifier was tested. They inhibited mousse formation at 0.1-0.2% concentrations (v/v). Emulsion inhibition by chemical treatment delayed the time of formation, but did not decrease water content. Demulsifying ability of dispersants and demulsifier was tested because biscous emulsion causes formidable problems in skimming, pumping and recovery operation. British demulsifier Alcohol 0 showed excellent emulsion breaking efficiency at 0.1% of emulsion Vol..

• Applied Biological Chemistry
• /
• v.33 no.4
• /
• pp.315-318
• /
• 1990

After technical pesticides and dispersants were dissolved in a volatile organic solvent, the wettable powders(WP's) were formulated by adsorbing the pesticide-dispersant solution to finely powdered porous synthetic silica without milling process. The median sizes of 11 WP'S were smaller than $8{\mu}m$, 9 of which had more than 80% suspensibility after 2 hours. It was possible In formulate 50% WP for liquid of fly technical pesticides. The pesticidal efficacies of WP's tested were comparable In commercial formulations regardless of suspensibilities of WP's.

• Journal of the Korea Convergence Society
• /
• v.9 no.12
• /
• pp.181-187
• /
• 2018

The historical consumption of oil dispersant was recorded during the protection plans after huge oil spill occurred in the Gulf of Mexico in 2010. As a well-known oil dispersant, Corexit 9500 was used and continuously blamed for the negative effects on environmental ecology. Nevertheless, US EPA still recognizes Corexit 9500 as a future oil dispersant that might be possibly sprayed again to oil slick. In order to develop alternative oil dispersants, it is important to impel the convergency works mainly from microbiologist, ecologist, environmentalist, chemist, and chemical engineer. In this paper, the major components of Corexit 9500 were introduced by chemical structures and physical properties. Presented were also the biodegradable process of dispersed oils and the possible candidates of biosurfactants.

• KSBB Journal
• /
• v.7 no.2
• /
• pp.107-111
• /
• 1992

Chayacterlstics of the sophorolipid produced from Candida bombiocola were investigated as an emulsifier of oil, a detergent or as a dispersant. Improved emulsification of crude oil was observed at high temperature ($70^{\circ}C$) with less than 1% concentration. Sophorolipid solution produced little foam even at reduced surface tension, however performance as a detergent of soiled cloths was poor. Dispersing and stabilizing abilities of sophorolipid solution were proved to be superior to those of chemical dispersants when examined by dispersing $Fe_2O_3$ or carbon black powders.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.13 no.4
• /
• pp.51-54
• /
• 2007

Surfactants can be used as a cosmetics and chemical dispersants. The variation of critical micelle concentration(CMC) with temperature for hexadecyl pyridinium bromide over the range $40^{\circ}C$ to $60^{\circ}C$ has been measured by drop methods. Thermodynamic quantities for micellization of hexadecyl pyridinium bromide in water have been calculated by polynominal equation.