The Effects of Surfactants on the Morphology of Colloidal Crystals in Self-assembly
- PDF / 800,579 Bytes
- 8 Pages / 595 x 842 pts (A4) Page_size
- 32 Downloads / 175 Views
0942-W11-34
The Effects of Surfactants on the Morphology of Colloidal Crystals in Self-assembly Zuocheng Zhou1, Qin Li1,2, Likui Wang3, and Xiusong Zhao3 1 Dept. of Chemical Engineering, Curtin University of Technology, Perth, Western Australia, 6845, Australia 2 Max-Planck Institute for Polymer Research, Ackermannweg 10, Mainz, 55128, Germany 3 Dept of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, Singapore
Abstract: Self-assembly method has been explored as an effective approach to fabricate three-dimensional (3D) photonic crystals (PCs), which have received much attention due to their potential applications in manipulating the behavior of photons. Till now, the experimental conditions, such as the concentration of colloidal suspension, temperature, humidity have been studied in detail. However, the effects of the solvent, which is important to the growth of 3D colloidal crystals, are seldom reported. In this research, various surfactant solutions are used as solvents of colloidal suspension during the fabrication of colloidal crystals. The effects of the surfactant on the quality and the morphology of the colloidal crystals are studied. The derived knowledge will be potentially useful in clarifying the mechanisms involved in the formation of colloidal crystals. Moreover, crystal structures other than fcc are expected to be obtained.
Introduction Recently, the fabrication of colloidal crystals using self-assembly method has received a great deal of attention [Xia et al., 2000] because the highly ordered structural colloidal crystals can be used as templates to synthesize porous materials [López, 2003], which have wide potential applications in photonics [Arsenault et al., 2004], opotoelectronics [Painter et al., 1999], data storage [Cumpston et al., 1999], chemical and biochemical sensors [Lee and Asher, 2000], and tissue engineering [Kotov et al., 2004], etc. In the self-assembly method, the growth of highly ordered colloidal arrays in large domains without the presence of defects is extremely important. Up to now, many techniques have been developed, such as gravitational sedimentation [Míguez et al., 1997], vertical deposition (VD) [Jiang et al., 1999], Langmuir-Blogett (LB) method [Gu et al., 2002] and float packing method [Im et al., 2002]. Among them, the VD method has gained a great deal of attention because by using this method the thickness and the surface morphology can be manipulated. Recently an improved VD method, namely flow-controlled vertical deposition (FCVD) method, was reported to fabricate colloidal crystals [Zhou and Zhao, 2004]. By using this improved method, the problem of concentration gradient of VD method can be overcome.
Normally, the colloidal crystals are prepared from suspension of colloidal spheres. Thus, the properties of the solvent, such as surface tension and contact angle, are important to the formation of the colloidal crystals. Especially in VD method, the capillary force, which is tightly related to the surface tension, is the main d
Data Loading...
