Size Selective Assembly of Colloidal Particles on a Template by Directed Self-Assembly Technique

• Published in: Langmuir Vol. 22; no. 19; pp. 8248 - 8252
• Main Authors: Varghese, Binni, Cheong, Fook Chiong, Sindhu, Swaminathan, Yu, Ting, Lim, Chwee-Teck, Valiyaveettil, Suresh, Sow, Chorng-Haur
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 12.09.2006
• Subjects: Chemistry; Colloidal state and disperse state; Colloids - chemistry; Exact sciences and technology; General and physical chemistry; Hydrophobic and Hydrophilic Interactions; Microscopy, Atomic Force; Particle Size; Physical and chemical studies. Granulometry. Electrokinetic phenomena; Polystyrenes - chemistry; Solutions - chemistry; Surface Properties; Water - chemistry; Self assembly; Confinement; Particle size; Microsphere; Spin; Suspension; Hydrophobicity; Submicron particle; Template; Topography; Centrifugal force; Diameter; Colloid particle
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la060732q

We report a simple and effective approach to organize micron- and submicron-sized particles in a size selective manner. This approach utilizes the template assisted directed self-assembly technique. A topographically patterned photoresist surface is fabricated and used to create an ordered array of colloidal particles from their aqueous suspensions. Assembly of particles on this template is then achieved by using a conventional spin coating technique. Feasibility of this technique to form a large area of patterned particle assemblies has been investigated. To arrange the particles on the template, the physical confinement offered by the surface topography must overcome a joint effect of centrifugal force and the hydrophobic nature of the photoresist surface. This concept has been extended to the size selective sorting of colloidal particles. The capability of this technique for sorting and organizing colloidal particles of a particular diameter from a mixture of microspheres is demonstrated.