Indoor air quality is an area of emerging importance for human health and well-being. Here we report that polymeric amine incorporated porous silicas (aminosilicas) have excellent adsorption properties for airborne formaldehyde, which is among the main irritant indoor air pollutants. Branched poly(ethyleneimine) (PEIBr) was incorporated into the ordered mesoporous silica SBA-15 and mesocellular foam silica (MCF). Figure 1 shows the adsorption capacity of the aminosilicas by SBA15 (?) and MCF (?) under a 100-200 ppm contamination level of airborne formaldehyde. An adsorption capacity of PEIBr bulk polymer (?) was also plotted. The gray bars in Figure 1 show the maximum amine loadings at which PEIBr could be stored inside of the silica pores of each silica support. The adsorption capacity increased along with amine loading before reaching the maximum amine loading, showing the highest amine capacity of 4.3 mmolHCHO/g for SBA-15 and 5.7 mmolHCHO/g for MCF aminosilicas. Once PEIBr was over incorporated, the adsorption performance decreased, with the extra aminopolymer behaving as a bulk polymer, rather than an accessible dispersed phase. These results indicate that the nanostructures of the support play a crucial role in effectively dispersing the aminopolymer and in adsorbing formaldehyde vapor. Because the adsorbed formaldehyde was chemically attached to aminosilica surface by covalent bonds, as verified by 13C solid state NMR analysis, it did not desorb from the aminosilicas under 130 �C. These adsorption characteristics suggest that aminosilicas can act as effective indoor air purifying materials. The adsorption mechanism will also be discussed.

Polymeric amine incorporated porous silicas as adsorbents for trapping of formaldehyde indoor air pollutants

247th National Meeting (2014)

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