Department of Physics, Engineering Physics & Astronomy

Department of Physics, Engineering Physics & Astronomy
Department of Physics, Engineering Physics & Astronomy

"Seashell" In-Situ or How to Design 3D Self-Assembled Nanoporous Shapes

Igor Yu. Sokolov
Department of Physics, Clarkson University, Postdam, NY, 13699-5820 USA

Date: Tuesday, February 5, 2002
Time: 10:30 AM
Location: Stirling 501


A creative combination of self-assembly and microfabrication may provide the way to future nanotechnology because of its inherent simplicity, high reliability and low cost of production. Recently the biomimetic synthesis of extraordinary curved nanoporous silica shapes, such as rods, discoids, spheres, tubes and hollow helicoids, obtained through the nucleation, growth and polymerization of silicate liquid crystals, brings closer to reality the possibility of creating a seashell in-situ, see an example of a mesoporous discoid in the figure below.

The ability to control curved shapes portends a variety of applications and new technologies where mesostructure and geometry determine function. The shapes are of great interest for a 3D spatial organization of nanosize wires, quantum dots, and in micro-optics. It is possible to grow metallic nanowires inside the pores using electroless plating, to put quantum dots inside by CVD, etc.

In this study, I am analyzing the problem of morphogenesis of mesoporous silica shapes and surface patterns. A theoretical basis will be outlined to describe the variety of forms and surface designs that result from the liquid crystal stage, silicification and rigidification of silicate liquid crystals. The main factors that are responsible for shape formation will be described. A few examples of numerical 3-D simulation are discussed to compare theory with experiment and to project beyond the experimental results. Figure below shows a few simulated examples of mesoporous shapes*. A new language of shapes may also emerge from this kind of research.

*Please note that the pictures that the abstract refers to are not posted on the website. Refreshments will be available after the talk.