Nanocomposites for CO2 Sequestration

CaO 40 wt%, gives a better performance than pure woUastonite powder due to its porosity and high specific surface area. In this way, without any special experimental conditions, a very short time of carbonation is required, 30 min, which represents a yield of 0.43 kg of C02/(kgofCaSi03h). 

High power ultrasound applied to an alkoxide/water mixture makes it possible to obtain nanostructured materials. The process is driven by the acoustic cavitation phenomenon. The cavities act as nanoreactors, where the hydrolysis reaction starts. The products (alcohol, water, and silanol) help continue the dissolution of that immiscible mixture. 

The process and the derived aerogels present the following features  

Slow reaction and flocculated products have been observed with neutral or basic water. 

There is a sonication energy dose at which the alkoxide/water mixture becomes homogeneous. This is taken as the threshold of the reaction. 

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