%0 Book Section %1 statphys23_0365 %A Tanaka, S. %B Abstract Book of the XXIII IUPAP International Conference on Statistical Physics %C Genova, Italy %D 2007 %E Pietronero, Luciano %E Loreto, Vittorio %E Zapperi, Stefano %K network pattern phase separation statphys23 surfactant topic-4 viscoelastic wetting %T Patterns in dilute surfactant solutions induced by the viscoelastic phase separation and wetting %U http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=365 %X Dilute solutions of surfactants exhibit a phase separation from a uniform micellar solution to a mixture between dilute and dense micellar solutions. Although the phenomena have been studied well, the macroscopic pattern formation of the system during the phase separation has not been fully understood. Since the finding of the viscoelastic phase separation 1, we know that fluid-fluid phase separation sometimes exhibit a rich variety of patterns when the viscoelastic properties of the two phases are widely different. Our aim of this study is to show how diverse the patterns formed by the surfactant solutions can be during the phase separation depending on the conditions such as concentration or temperature. Using a surfactant $C_12E_5$, we show that the phase separation between the dilute and dense micellar solutions causes a temporal network pattern (Figure) formed by the dense micellar phase. It is noteworthy that the dense phase is the minor phase with small volume fraction, and this is characteristic to the viscoelastic phase separation 1. The origin of this network formation is thus thought to come from the difference in the viscoelastic properties between the dilute and dense micellar phases. Recently, Bernheim-Groswasser et al. showed that the dense micellar phase consists of a concentrated network of threadlike micelles. We consider that this structure gives rise to dynamic asymmetry between the two phases. In addition to the network patterns, we also observed wetting-induced behaviors during the phase separation. This adds the complexity to the patterns formed by this system. In the presentation, we will show these pattern formations and discuss their underlying mechanisms. 1) H. Tanaka, Phys. Rev. Lett. 76, 787 (1996), H. Tanaka, Phys. Rev. E 59, 6842 (1999).\\ 2) A. Bernheim-Groswasser, E. Wachtel, and Y. Talmon, Langmuir 16, 4131 (2000).

@incollection{statphys23_0365, abstract = {Dilute solutions of surfactants exhibit a phase separation from a uniform micellar solution to a mixture between dilute and dense micellar solutions. Although the phenomena have been studied well, the macroscopic pattern formation of the system during the phase separation has not been fully understood. Since the finding of the viscoelastic phase separation [1], we know that fluid-fluid phase separation sometimes exhibit a rich variety of patterns when the viscoelastic properties of the two phases are widely different. Our aim of this study is to show how diverse the patterns formed by the surfactant solutions can be during the phase separation depending on the conditions such as concentration or temperature. Using a surfactant $\rm C_{12}E_5$, we show that the phase separation between the dilute and dense micellar solutions causes a temporal network pattern (Figure) formed by the dense micellar phase. It is noteworthy that the dense phase is the minor phase with small volume fraction, and this is characteristic to the viscoelastic phase separation [1]. The origin of this network formation is thus thought to come from the difference in the viscoelastic properties between the dilute and dense micellar phases. Recently, Bernheim-Groswasser et al. showed that the dense micellar phase consists of a concentrated network of threadlike micelles. We consider that this structure gives rise to dynamic asymmetry between the two phases. In addition to the network patterns, we also observed wetting-induced behaviors during the phase separation. This adds the complexity to the patterns formed by this system. In the presentation, we will show these pattern formations and discuss their underlying mechanisms. 1) H. Tanaka, Phys. Rev. Lett. 76, 787 (1996), H. Tanaka, Phys. Rev. E 59, 6842 (1999).\\ 2) A. Bernheim-Groswasser, E. Wachtel, and Y. Talmon, Langmuir 16, 4131 (2000).}, added-at = {2007-06-20T10:16:09.000+0200}, address = {Genova, Italy}, author = {Tanaka, S.}, biburl = {https://www.bibsonomy.org/bibtex/2093d106cc05b8d409470ab347d28b302/statphys23}, booktitle = {Abstract Book of the XXIII IUPAP International Conference on Statistical Physics}, editor = {Pietronero, Luciano and Loreto, Vittorio and Zapperi, Stefano}, interhash = {3f85bdacaf108f11a0c24b1072083ff5}, intrahash = {093d106cc05b8d409470ab347d28b302}, keywords = {network pattern phase separation statphys23 surfactant topic-4 viscoelastic wetting}, month = {9-13 July}, timestamp = {2007-06-20T10:16:18.000+0200}, title = {Patterns in dilute surfactant solutions induced by the viscoelastic phase separation and wetting}, url = {http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=365}, year = 2007 }