• Title/Summary/Keyword: N-Octadecyl pyridinium bromide

Search Result 2, Processing Time 0.019 seconds

The Effect of Temperature on the Critical Micelle Concentration of Cationic Surfactant for Chemical Dispersants (유처리제용 양이온 계면찰성제의 임계미셀농토에서 온도의 효과)

  • kim, Yeoung-Chan
    • 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.

  • PDF

Thermodynamic Characteris tics of Surface Activities of N-Alkyl Pyridinium Bromide (N-Alkyl Pyridinium Bromide류의 계면활성에 대한 열역학적 특성)

  • Kim, Yeoung-Chan;Kim, Dong-Sik;Jeong, Soon-Wook;Shon, Byoung-Chung
    • Journal of the Korean Applied Science and Technology
    • /
    • v.8 no.2
    • /
    • pp.105-114
    • /
    • 1991
  • In relation to the preparation of Langmuir-Blodgett thin film, four kinds of N-alkylpyridiniurn bromide were synthesized. The values of surface tensions of these materials, measured with a Traube stalagmometer, gave the relationship between the critical micells hydrophobic radical and between CMC and temperature. Values of thermodynamic properties(${\Delta}H^0_m,\;{\Delta}S^0_m,\;{\Delta}G^0_m,$) for the formatoin of micelle were also obtained. Experiments gave the following results; at the temperature range between 40 and 60$^{\circ}C, CMC of Hexadecyl-, Octadecyl-, Eicosyl-, and Docosyl-Pyridinium Bromide were $7.64{\times}10^{-4}{\sim}9.13{\times}10^{-4},\;3.85{\times}10^{-4}{\sim}4.60{\times}10^{-4},\;2.00{\times}10^{-4}{\sim}2.39{\times}10^{-4},\;and\;1.07{\times}10^{-4}{\sim}1.28{\times}10^{-4}$ mol/l, respectively. Surface tension, ${\Gamma}_{CMC}$, of those were 33.49${\sim}$36.00, 34.78${\sim}$37.61, 35.49${\sim}$37.61 and 38.76${\sim}$55.80 dyne/cm, respectively, The relationship between CMC and the mumber of carbon atoms in the hydrophobic radical, N was expressed as follows : Log(CMC)=A-BN where A and B are constants. At the temperature range between 40 and 60$^{\circ}C$, the change of Gibbs evergy (${\Delta}G_m$) for one methylene group ($-CH_2-$) were -0.65RT, respectively, The minus values of enthalpy change (${\Delta}H_m$) suggest that the formation of micelle is exothermic. Additionally, the overall increase in the entropy change (${\Delta}S_m$) with respect to the temperature increase suggests that the formation of micelle is attained by a exothermic enthalpy directed process.