This surfactant can be used as a cosmetics and chemical dispersants. The variation of critical micelle concentration(CMC) with temperature for N-eicosyl pyridinium bromide over the range 40℃ to 60℃ has been measured by drop methods. Thermodynamic quantities for micellization of N-eicosyl pyridinium bromide in water have been calculated by polynominal equation.

화장품과 유처리제 등에 응용할 수 있는 양이온 계면활성제인 N-octadecyl pyridinium bromide를 사용하여 온도 40~60℃ 범위에서 적하법을 이용한 임계미셀농도를 적용 미셀형성에 따른 열역학적 특성(자유에너지, 엔탈피, 엔트로피, 열용량)을 조사하였다. 그 결과 자유에너지 변화는 온도가 증가함에 따라 감소함을 알 수 있었다.

화장품과 유처리제 등에 응용할 수 있는 계면활성제인 hexadecyl pyridinium bromide를 사용하여 온도 40~60℃ 범위에서 임계미셀농도를 적하법으로 측정한 결과를 이용하여 미셀형성에 따른 열역학적 양을 다항식으로 계산하였다.

The critical micelle concentration (CMC) at which micelles start to form from a surfactant solution is usually measured in terms of conventional concentration units. However, the thermodynamic potentials are expressed in terms of mole fraction XCMC and XCMC cannot be directly measured experimentally. The Gibbs free energy, δG*mic, in particular is related to XCMC through δG*mic = RTlnXCMC. When it comes to CMC, the molar CMC, CCMC, differs only by the proportionality C-1w with Cw being the molarity of water. Hence, CCMC is found to be a proper representation of CMC. However, in calculation of δG*mic and other thermodynamic potentials from the CMC, XCMC or CCMC/Cw should be used.

The environmental behaviors of polycyclic aromatic hydrocarbons (PAHs) are mainly governed by their solubility and partitioning properties on soil media in a subsurface system. In surfactant-enhanced remediation (SER) systems, surfactant plays a critical role in remediation. In this study, sorptive behaviors and partitioning of naphthalene in soils in the presence of surfactants were investigated. Silica and kaolin with low organic carbon contents and a natural soil with relatively higher organic carbon content were used as model sorbents. A nonionic surfactant, Triton X-100, was used to enhance dissolution of naphthalene. Sorption kinetics of naphthalene onto silica, kaolin and natural soil were investigated and analyzed using several kinetic models. The two compartment first-order kinetic model (TCFOKM) was fitted better than the other models. From the results of TCFOKM, the fast sorption coefficient of naphthalene (k1) was in the order of silica > kaolin > natural soil, whereas the slow sorbing fraction (k2) was in the reverse order. Sorption isotherms of naphthalene were linear with organic carbon content (foc) in soils, while those of Triton X-100 were nonlinear and correlated with CEC and BET surface area. Sorption of Triton X-100 was higher than that of naphthalene in all soils. The effectiveness of a SER system depends on the distribution coefficient (KD) of naphthalene between mobile and immobile phases. In surfactant-sorbed soils, naphthalene was adsorbed onto the soil surface and also partitioned onto the sorbed surfactant. The partition coefficient (KD) of naphthalene increased with surfactant concentration. However, the KD decreased as the surfactant concentration increased above CMC in all soils. This indicates that naphthalene was partitioned competitively onto both sorbed surfactants (immobile phase) and micelles (mobile phase). For the mineral soils such as silica and kaolin, naphthalene removal by mobile phase would be better than that by immobile phase because the distribution of naphthalene onto the micelles (Kmic) increased with the nonionic surfactant concentration (Triton X-100). For the natural soil with relatively higher organic carbon content, however, the naphthalene removal by immobile phase would be better than that by mobile phase, because a high amount of Triton X-100 could be sorbed onto the natural soil and the sorbed surfactant also could sorb the relatively higher amount of naphthalene.