The following is an outline of the project:

1. Process Standardization. A new steel mold will be designed for the fabrication process using the hot-press. A standard aerogel recipe will be used to produce consistent monoliths. This is necessary because once the process is optimized that process will remain constant throughout the study so that the subsequent results can be compared to the standard.

2. Standardized Characterization. The samples from the above test will be characterized. We will measure density using a microbalance, thermal conductivity using a thermal constants analyzer and porosity using a nitrogen gas-adsorption system. Electromagnetic transmission characteristics may also be determined using the integrating sphere spectrophotometer (depending on the time available for the project). These results will serve as the baseline characteristics for future comparison.

3. Design of Experiments. I will study the effect of precursor chemical (TMOS v/s TEOS), the catalyst (acidic versus basic), water content, alcohol content and any other variable that I discover through the literature search. A full factorial study will be conducted involving all the variables identified. Venkateswara Rao et al. (1994) performed a similar study by varying the molar ratios of precursor, catalyst, solvent and water and studying the effect on monolithicity of TMOS silica aerogels. Here they used the nitrogen flushing technique for evacuation.

4. Further Characterization. The successful monoliths from the DOE experiment will be characterized to determine the density, conductivity and the porosity (and transmission characteristics, if time permits). This will allow us to understand the effects of the tested variables on aerogel properties.

A secondary objective is to evaluate another method that involves using an autoclave and carbon dioxide in the extraction process. This process involves solvent exchange where the methanol is replaced by gaseous carbon dioxide and then extracted. After the above objectives are achieved the carbon dioxide supercritical extraction technique will be investigated and the aerogels characterized in a similar fashion as explained above (refer to Wagh, 1998).