ISSN:
1435-1536
Keywords:
Emulsionstability
;
nonionicsurfactants
;
ζpotential
;
stericstabilization
;
rapidcoalescence
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Rapid coalescence was studied on liquid paraffin emulsion stabilized with a series of poly(oxyethylene) dodecyl ethers [C12H25 (EO),n=1, 2, 3, 4, 5, 6, 7, 8] and of poly(oxyethylene) nonylphenyl ethers [C9H19Ф(EO) n ,n=2, 4, 5, 6, 12]. The turbidity of emulsion was measured as a function of the solution pHs at constant ionic strength of 0.1 mol dm−3. As a result, it was found that the emulsions (which were formed with C12H25(EO) n surfactants having less than four oxyethylene groups, or with C9H19 Ф(EO) n surfactants having less than six oxyethylene groups) brought about rapid coalescence in the bulk pH between 2.0∼3.5, which corresponded to the zero point of charges for the emulsions of the present systems. According to the Tadros treatment for emulsion flocculation, the total flocculation potennual was estimated as a function of the distance relative to the number of oxyethelene groups in the surfactants. The critical coalescence energy was obtained as −343 ×10−19 J for the C12H25(EO) n surfactants and −2.14×10−19) J for the C9H19 Ф(EO) n surfactants. Furthermore, the formation of a hole for coalescence was estimated under the simple assumption that the coalescence was caused only by the energy dissipation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00776147
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