How acid attack and high temperature affect the microstructure of adsorbent geopolymers

Abstract

Geopolymers (GPs) are versatile materials that have low intrinsic porosity. This characteristic can be used as a motivator for the development of porous GPs, since separation processes require adsorbents with a high specific area. Thus, this work aimed to elucidate how acid attack and calcination affect the microstructure of GPs. For this purpose, a GP was exposed to H2SO4 and 200 °C, being later characterized in terms of morphology, mineralogy, functional groups, and textural properties. Acid etching and calcination proved to be effective strategies for surface area improvement, making the modified GP a strong candidate for use as an adsorbent.

Keywords

• Sulfuric acid
• Calcination
• Geopolymer modification
• Specific surface area