Physical activation and characterization of tannin-based foams enforced with boric acid and zinc chloride

Abstract

In this study, tannin-furanic-based foams enforced with H3BO3 and ZnCl2 are investigated, as well as their properties such as mechanical strength, specific surface area, and pore size distribution. From an industrial point of view, the aforementioned properties of these foams play a key role when used as catalyst, adsorbent, or gas storing materials. Therefore, this study aims to prove that such enforced tannin-furanic foams are promising materials for these types of applications. According to the results, materials that are up to five times stronger can be achieved by carbonizing the foams in comparison to maturing them. With physical activation, it was possible to obtain a specific surface area as high as 845 m2 /g with a pore volume of up to 0.35 cm3 /g. Chemical activation, using ZnCl2 as the activating agent, produced a specific surface area and pore volume of 737 m2 /g and 0.31 cm3 /g. However, the pore sizes were mostly microporous, independently of activation procedure used.