Suggestion of New Correlations for Drop/Interface Coalescence Phenomena in the Absence and Presence of Single Surfactant

Document Type : Research Article

Authors

Department of Chemical Engineering, Faculty of Engineering, Tehran University, P.O.Box. 11365-4563, Tehran, I.R. IRAN

Abstract

After designing and constructing a coalescence cell, drop/interface coalescence phenomenon was studied in the absence and presence of single surfactant.Two surface active agents of sodium dodecyl sulfate and 1-decanol were used. Distilled water was used as dispersed phase. Toluene, n-heptane and aqueous 60% (v/v) of glycerol were selected as continuous phases, separately. It was found that the coalescence time increased with both drop size and falling height. When the chemical system suffered from multi-step (partial) coalescence, number of coalescence steps decreased with either of these variables. Addition of a single ionic or nonionic surfactant made the drop size smaller, and hence caused the onset of partial coalescence. When the surfactant was soluble in the drop phase, it increased the time more effectively. Also, It was found that the viscosity of the continuous phase played an important role in drop-interface coalescence. Based on the experimental results, new correlations were proposed. Then, the results were compared with the other models by application of the existing condition.

Keywords

Main Subjects

References

[1] Sinegribova, O.A., Andreev, A.Y., Voronin, O.V. and Dvoeglazov, K.N., The Influence of Silicic Acid on the Coalescence of Drops in the Extraction system TBP-HNO3(HCl), Logsdail, D.H. and Slater, M.J., Eds., in “Solvent Extraction in the Process Industries”, Vol. 3, Elsevier, London, UK (1993).
[2] Lin,C.-Y. and Slattery, J.C., Thining of a Liquid Film as a Small Drop or Bubble Approaches a Fluid-Fluid Interface, AIChE J., 28, 786 (1982).
[3] Lyu, S.-P., Bates, F.S. and Macosko, C.W., Coalescence in Polymer Blends during Shearing, AIChE J., 46, 229 (2000).
[4] de Gennes, P.G., Some Remarks on Coalescence in Emulsions or Foams, Chem. Eng. Sci. , 56, 5449 (2001).
[5] Henschke, M., Schlieper, L.H. and Pfennig, A., Determination of a Coalescence Parameter from Batch Settling Experiments, Chem. Eng. J., 85, 369 (2002).
[6] Davies, G.A., Mixing and Coalescence Phenomena in Liquid-Liquid Systems, Thornton, J.D., Ed., in “Science and Practice of Liquid-Liquid Extraction”, Vol. 1, Oxford, London, UK (1992).
[7] Yiantsios,S.G. and Davis, R.H., On the Buoyancy Driven Motion of a Drop towards a Rigid Surface or a Deformable Interface, J. Fluid Mech. , 217, 547(1990).
[8] Ban, T., Kawaizumi, F., Nii, S. and Takahashi, K., Study of Drop Coalescence Behavior for Liquid/Liquid Extraction Operation, Chem. Eng. Sci., 55, 5385 (2000).
[9] Hartland, S., Coalescence in Dense Packed Dispersion, Ivanov, I.B., Ed., in “Thin Liquid Films”, Marcel Dekker, New York, NY (1988).
[10] Jeffreys, G.V. and Davies, G.A., Coalescence of Liquid Droplets and Liquid Dispersions, Hanson, C., Ed., in “Recent Advances in Liquid/Liquid Extraction”, Pergamon Press (1971).
[11] Laddha, G.S. and Degaleesan, T.E., Dispersion and Coalescence, Lo, T.C., Baird, M.H.I. and Hanson, C., Eds., in “Handbook of Solvent Extraction”, Krieger, Malaber, FL (1991).
[12] Khadiv-Parsi, P. and Moosavian, M.-A., The Influence of Bicomponent Mixed Surfactants on Drop/Interface Coalescence, Iran. J. Chem. & Chem. Eng., 23, 89 (2004).
[13] Yeo,  L.Y.,  Matar,  O.K.,  Susana Perez de Ortiz, E. and Hewitt, G.F., Film Drainage between Two Surfactant- Coated Drops Colliding at Constant Approach Velocity, J. Colloid Interf. Sci., 257, 93 (2003).
[14]  Khadiv-Parsi, P., Suggestion and Analysis of New Correlations in the Drop-Interface Coalescence and the Droplet Dispersion Bed Phenomena, Ph.D. Thesis, Faculty of Engineering, University of Tehran, Iran (2001).
[15] Moosavian, M.-A., Bahmanyar, H., Khadiv-Parsi, P. and Ivani, J., Investigation and Analysis of Influence of Drop Size and Falling Distance on Drop-Interface Coalescence in Proc. 5th National and 4th International Chem. Eng. Congress”; University of Shiraz, Shiraz, 24-27 April (2000).
[16] Moosavian M.-A., Bahmanyar,H. and Khadiv-Parsi, P.,  The Effects of Drop Size, its Falling Distance and Fluctuations on Drop-Interface Coalescence Time, J. Faculty Eng., University of Tehran, 34, 91 (2001).
[17] Khadiv-Parsi,P., Moosavian, M.-A. and Bahmanyar, H., The Influence of Surfactants on Drop-Interface Coalescence Phenomena, sixth National Iranian Chem. Eng. Congress, Isfahan University of Technology, Isfahan (May 2001).
[18] Bart, H.-J., Berger, R., Míšek, T., Slater, M.J., Shröter, J. and Wachter, B., Recommended Systems for Liquid Extraction Studies, Godfrey, J.C. and Slater, M.J., Eds., in “Liquid-Liquid Extraction Equipment”, John Wiley and Sons, New York, NY (1994).
[19] Skelland, A.H.P. and Minhas, S.S., Dispersed Phase Mass Transfer during Drop Formation and Coalescence in Liquid-Liquid Extraction, AICHE J., 17, 1316 (1971).
[20] Nikolov, A.D. and Wasan, D.T., Effects of Surfactant on Multiple Stepwise Coalescence of Single Drops at Liquid/Liquid Interfaces, Ind. Eng. Chem. Res., 34, 3653 (1995).
[21] Guzun-Stoica, A., Kurzeluk, M. and Floarea, Q., Experimental Study of Marangoni Effect in a Liquid/Liquid System, Chem. Eng. Sci., 55, 3813 (2000).
[22] Blawzdziewicz, J., Cristini, V. and Loewenberg, M., Near-Contact Motion of Surfactant-Covered Spherical Drops: Ionic Surfactant, J. Colloid Interf. Sci., 211, 355 (1999).
[23] Bazhlekov, I.B., Chesters, A.K. and van de Vosse, F.N., The Effect of the Dispersed to Continuous Phase Viscosity Ratio on Film Drainage between Interacting Drops, Int. J. Multiphase Flow, 26, 445 (2000).
[24] Jeffreys, G.V. and Hawksley, J.L., Coalescence of Liquid Droplets in Two-Component Two-Phase Systems: Part I. Effect of Physical Properties on the Rate of Coalescence, AIChE J., 11, 413 (1965).

Files

Share

How to cite

Statistics