کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5364533 | 1503702 | 2012 | 5 صفحه PDF | دانلود رایگان |
Dynamic interfacial tension (DIT) between aqueous solution of 3-alkoxy-2-hydroxypropyl trimethyl ammonium chloride (RnHTAC) and n-octane was measured using spinning drop method. The effects of RnHTAC concentration (the concentration below the CMC) and temperature on DIT have been investigated. The cause of the change of DIT with time has been discussed. The effective diffusion coefficient, Da, and the adsorption barrier, Éa, have been obtained with extended Word-Tordai equation. The results show that the higher the concentration of the surfactant is, the smaller the DIT will be and the lower the curve of the DIT, and the aqueous RnHTAC solutions follow a mixed diffusion-activation adsorption mechanism. With increase of RnHTAC concentration in the bulk solution, Da decreases and Éa increases. Da of aqueous R14HTAC solution decreases from 0.090 Ã 10â13 m2 sâ1 to 0.081 Ã 10â13 m2 sâ1 and Éa increases from 10.12 kJ molâ1 to 11.89 kJ molâ1, with the temperature increasing from 30 °C to 50 °C. This phenomenon indicates that the diffusion tendency becomes weak with the strengthening of the interaction between the surfactant molecules and that the thermo-motion of molecules benefits interface adsorption.
⺠The effects of concentration and temperature of RnHTAC on the DIT were investigated. ⺠Interfacial adsorption mechanism of the aqueous RnHTAC solutions was studied. ⺠These studies can extend the application of RnHTAC in a wide variety of fields.
Journal: Applied Surface Science - Volume 261, 15 November 2012, Pages 237-241