Hydrophobic Mesoporous Silica Composition
There is a need for improvements in the preparation of porous materials that are active for binding metals from solution on an industrial scale. The materials have the composition of organic-inorganic metal oxides and prior art is difficult to synthesize or to achieve ideal porosity for metal binding.
Description of Technology
This technology is a method for preparing a mesoporous organosilica for catalysis and adsorbent activities. The hydrophobic mesoporous molecular sieves (HMS) have an inorganic oxide composition, and the surface of the mesopore walls are reactive organic silane moieties.
The material is prepared by co-condensation of different organoxy-functional silane compounds like tetraethoxysilane (TEOS) in an aqueous solution of templating octylamine micelles (spheres of aggregating amine surfactant molecules). The pore size of the materials can be controlled by adjusting the stoichiometry of the solution mixture. The templating amine surfactant can be removed by ethanol extraction to yield a stable organo-functionalized molecular sieve.
- More efficient metal binding: Tunable mesopores to achieve appropriate diffusion through pores for enhanced metal binding or catalysis.
- Lower costs: The templating agent is introduced through direct synthesis route to achieve a template-induced structure rather than grafting method. The templating agent can be recovered and recycled.
- Integrable: Relatively mild conditions are used and conventional processing.
The compositions are particularly useful as catalysts and adsorbents. There are many catalytic applications such as Knoevenagel condensations, selective monoglyceride synthesis, and potential for separating enantiomers in fine chemicals and pharmaceuticals.
The technology also has applications in environmental remediation of metal containing aqueous solutions as an absorbent in purifications, for example, in the separation and trapping of heavy metals such as cadmium, arsenic, lead, and mercury.
The invention is ready for a pilot production scale-up effort.
US 6649083 (issued Nov 18, 2003)
US 6465387 (issued Oct 15, 2002)
Thomas Pinnavaia, Louis Mercier
For Information, Contact:
Michigan State University