Document Type : Original Article


1 Department of Chemistry, Khajeh Nasir Toosi University of Technology, Tehran, Iran

2 Research Center Karaj Moallem, Karaj, Iran



In this study, a geopolymer composite has been prepared using metakaolin/mica/talc (MMT) and modified with nanosilica (MMT/Nanosilica) which can be used for the carbone dioxide (CO2) absorption in filters. The MMT geopolymer were restructured by the alkaline activating agent (NaOH) in the presence of the foaming agent, Heydrogen Peroxide (H2O2). The foaming agent of  H2O2 creates an amorphous and porous geopolymeric composite by producing oxyigen. To check the nanosilica effectiveness in the optimal CO2 absorption in the MMT filter, the different amounts of nanosilica were added to the MMT composite. Since geopolymers do not have sufficient flexibility and porosity, polyurethane foam impregnated with polyvinyl alcohol (PVA) was used as a template for the MMT mixture which has high flexibility, malleability, and porosity. The amount of CO2 absorption on the MMT/Nanosilica filter was estimated by the pH measurement of alkaline solution into which CO2 is finally introduced.The results showed the high capability of MMT/Nanosilica filter in CO2 absorption. The optimal amount of nanosilica was determined in the MMT geopolymer. Fourier transform infrared spectroscopy (FTIR) admited the effective CO2 absorption. Likewise, the images of the field emission scanning electron microscope (FESEM) showed the cavity structure with micron and nano dimensions.

Graphical Abstract

Flexible and porous geopolymer filter of metakaolin/ mica/talc (MMT) containing nanosilica for CO2 absorption


Main Subjects


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