Thermodynamics of Formation of Biological Microemulsion (with Cinnamic Alcohol, Aerosol OT, Tween 20, and Water) and Kinetics of Alkaline Fading of Crystal Violet in Them
✍ Scribed by Lana Mukhopadhyay; Nita Mitra; Pranab K. Bhattacharya; Satya P. Moulik
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- English
- Weight
- 155 KB
- Volume
- 186
- Category
- Article
- ISSN
- 0021-9797
No coin nor oath required. For personal study only.
✦ Synopsis
measured the enthalpies of solution of water in chloroform
The ternary phase diagrams for the formation of biological mias well as chloroform in water aided by cationic, anionic, croemulsions of the combinations CA/AOT/water and CA/Tween and nonionic surfactants. Thermal inversion for both water 20/water have been presented. The thermodynamics of solution and oil dispersions near the phase separation point for certain of water in AOT/CA as well as in Tween 20/CA forming w/o compositions has been observed. Chemical and biochemical microemulsions and solution of oil in Tween 20/water forming reactions in nonbiological microemulsions have been studied o/w microemulsions have been calorimetrically studied. The solumoderately (13-17). Inversion of sucrose and hydrolysis of tion processes are essentially exothermic (with a few exceptions) p-nitrophenyl phosphate with alkaline phosphatase in such and have yielded negative entropies, i.e., producing an ordering microemulsion media have been reported from our laboraeffect. This has been supported by the measured specific heats of the resulting solution. The pseudo-first-order rate constants (k 1 ) tory (18, 19). Alkaline hydrolysis of crystal violet in microfor the alkaline fading of crystal violet in w/o microemulsion meemulsion media has been studied on a number of occasions dium for the CA/AOT/water and CA/TW 20/water have been (20-25); a recent study in aqueous and nonaqueous microfound to depend on [water]/[AOT] mole ratio (v) with maxima at emulsion media has been reported by us (26). Kinetic studies v Å 10. For o/w preparations of CA/TW-20/water, k 1 has shown in biological microemulsion medium are rare in literature. maximum at [CA]/[TW-20] mole ratio v Å 2, whereas the k 2 Moberger and Larsson (5) have reported the kinetics of oxivalue has increased with v. The salt effect on the reaction has dation of fats in biological microemulsion containing vegetashown significant deviation from expectation in w/o microemulble oil. sion. The free energies of activation for the w/o and o/w systems In this presentation, we report the energetics of the formaare of the same order, whereas both DH ‡ and DS ‡ values differ tion of biological microemulsions (of both w/o and o/w types significantly.