Preparation of Doublet, Triangular, and Tetrahedral Colloidal Clusters by Controlled Emulsification

@article{citeulike:1389134, abstract = {Abstract: We describe a six-step method for making colloidal clusters of 2, 3, or 4 silica particles with a radius of 1.2 m. This method, originally described by Manoharan et al. (Manoharan, V. N.; Elsesser, M. T.; Pine, D. J. Science 2003, 301, 483), is based on the encapsulation of silica spheres in emulsion droplets. The originality of our work lies in the preparation of monodisperse emulsions, which allows us to obtain some high yields of small aggregates over a wide range of conditions. Using optical microscopy and disk centrifugation, we show that the relative fractions of 2, 3, and 4 particle aggregates are controlled by the emulsification conditions, particularly the concentration of silica in the dispersed phase. Our best yields are obtained using low to moderate shear rates, a highly viscous continuous phase, and intermediate amounts of silica. The sedimentation of the colloidal solution into a gradient of concentration leads to aqueous suspensions of identical clusters. Since the overall process can easily be scaled up, large quantities of identical clusters may be prepared, which should allow the thermodynamic properties of these new colloidal objects to be measured for the first time. These nonspherical particles could serve as building blocks for more complex assemblies, such as colloidal crystals which could find applications as photonic materials.}, address = {Laboratoire des Collo\"{i}des et Mat\'{e}riaux Divis\'{e}s-UMR 7612 (UPMC-CNRS-ESPCI) ESPCI, 10 rue Vauquelin, 75231 Paris Cedex 05, France, Laboratoire des Milieux Dispers\'{e}s Alimentaires, Institut des Sciences et Techniques des Aliments de Bordeaux, Av. des Facult\'{e}s, 33405, Talence Cedex, France, and Department of Physics, New York University, 4 Washington Place, New York, New York 10003}, author = {Zerrouki, D. and Rotenberg, B. and Abramson, S. and Baudry, J. and Goubault, C. and Leal-Calderon, F. and Pine, D. J. and Bibette, J. }, citeulike-article-id = {1389134}, comment = {another paper on the manoharan clusters...they use monodisperse emulsions to increase the control they have over the size and type of the clusters.}, doi = {10.1021/la051765t}, journal = {Langmuir}, keywords = {colloidal, emulsions, monodisperse, qualifier, self-assembly}, month = {January}, number = {1}, pages = {57--62}, posted-at = {2007-06-14 04:53:18}, priority = {4}, title = {Preparation of Doublet, Triangular, and Tetrahedral Colloidal Clusters by Controlled Emulsification}, url = {http://dx.doi.org/10.1021/la051765t}, volume = {22}, year = {2006} }

TY - JOUR ID - citeulike:1389134 L3 - citeulike-article-id:1389134 TI - Preparation of Doublet, Triangular, and Tetrahedral Colloidal Clusters by Controlled Emulsification JF - Langmuir VL - 22 IS - 1 SP - 57 EP - 62 AD - Laboratoire des Colloïdes et Matériaux Divisés-UMR 7612 (UPMC-CNRS-ESPCI) ESPCI, 10 rue Vauquelin, 75231 Paris Cedex 05, France, Laboratoire des Milieux Dispersés Alimentaires, Institut des Sciences et Techniques des Aliments de Bordeaux, Av. des Facultés, 33405, Talence Cedex, France, and Department of Physics, New York University, 4 Washington Place, New York, New York 10003 N2 - Abstract: We describe a six-step method for making colloidal clusters of 2, 3, or 4 silica particles with a radius of 1.2 m. This method, originally described by Manoharan et al. (Manoharan, V. N.; Elsesser, M. T.; Pine, D. J. Science 2003, 301, 483), is based on the encapsulation of silica spheres in emulsion droplets. The originality of our work lies in the preparation of monodisperse emulsions, which allows us to obtain some high yields of small aggregates over a wide range of conditions. Using optical microscopy and disk centrifugation, we show that the relative fractions of 2, 3, and 4 particle aggregates are controlled by the emulsification conditions, particularly the concentration of silica in the dispersed phase. Our best yields are obtained using low to moderate shear rates, a highly viscous continuous phase, and intermediate amounts of silica. The sedimentation of the colloidal solution into a gradient of concentration leads to aqueous suspensions of identical clusters. Since the overall process can easily be scaled up, large quantities of identical clusters may be prepared, which should allow the thermodynamic properties of these new colloidal objects to be measured for the first time. These nonspherical particles could serve as building blocks for more complex assemblies, such as colloidal crystals which could find applications as photonic materials. KW - colloidal KW - emulsions KW - monodisperse KW - qualifier KW - self-assembly N1 - another paper on the manoharan clusters...they use monodisperse emulsions to increase the control they have over the size and type of the clusters. AU - Zerrouki, D AU - Rotenberg, B AU - Abramson, S AU - Baudry, J AU - Goubault, C AU - Leal-Calderon, F AU - Pine, DJ AU - Bibette, J PY - 2006/01/03/ UR - http://dx.doi.org/10.1021/la051765t ER -