STUDI TERMODINAMIKA PEMBENTUKAN MISEL NATRIUM DODESIL SULFAT DALAM AIR MENGGUNAKAN MODEL AKSI-MASSA DAN TERMODINAMIKA SISTEM KECIL (THERMODYNAMICS STUDY ON MICELLIZATION OF AQUEOUS SOLUTION OF SODIUM DODECYL SULFATE USIN
| Main Author: | Perpustakaan UGM, i-lib |
|---|---|
| Format: | Article NonPeerReviewed |
| Terbitan: |
[Yogyakarta] : Universitas Gadjah Mada
, 2001
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| Subjects: | |
| Online Access: |
https://repository.ugm.ac.id/25568/ http://i-lib.ugm.ac.id/jurnal/download.php?dataId=8564 |
Daftar Isi:
- ABSTRACT Thermodynamics of micelle formation of aqueous solution of sodium dodecyl sulfate has been investigated by measuring the conductivity in various temperature of solution, hardness and pH of water, respectively. This thermodynamics study based on mass-action model and thermodynamics of small system. The determination of critical micelle concentration was done by plotting the conductivity versus concentration of surfactant solution. Calculations of agregation number (n) were carried out using Huisman's empirical equation , the logarithmic of micellization constants (logIC.) was calculated by modification of mass-action model by introducing the charge of monomer which form the micelle, the degree of counter ion assosiation 66) was calculated using combination of Stokes law about viscosity of solution and Kohlrausch law for electrolyte solution, the number of free monomer (mf) was calculated using the differentiation of Huisman's equation for concentration above CMC. The calculation of mf is an iteration technique using a computer program. The thermodynamic functions of micelle formation was calculated by mass-action model and thermodynamics of small system using computer program. The result of this research showed that the elevation of temperature will enhance critical micelle concentration, and at the relatively high temperature, above 313,15 K for SDS solution in aquadest, the critical micelle concentration is relatively constant. The hardness of water support the micelle formation, showed by the decreasing of CMC value in water-1 and water-2 from CMC value in aquadest, as the effect of hardness ions in water. Acid condition (pH-2) is very conducive for micelle formation, indicated by the smallest CMC for all water, the biggest log K. (rnicellization constant), and the most negative value of AGcno. The results of .thermodynamic functions calculation indicated that micelle formation was caused mainly by condensation of hydrophobic groups as the result of induced-dipoles interaction between surfactant molecules. Keywords: micellization, sodium dodecyl sulfate, thermodynamics