Fabrication of expanded vermiculite using the mixed methods of microwave and H2O2 and their application for adsorption

Vermiculite (VER) is a type of clay mineral abundant in reserves, with low cost and environmental friendliness. There are many chemicals used to expand VER such as HCl, H2SO4, etc. In this study, vermiculite was expanded using a mixed methods using microwave irradiation with H2O2. Factors affecting the expansion process of vermiculite minerals such as VER:H2O2 ratio, H2O2 concentration, drying temperature, drying time, microwave time, soaking time were investigated and optimized. VER material was determined to be optimally expanded at a VER:H2O2 ratio of 1:6, with 30% H2O2 concentration, soaking for 60 minutes, drying at 60°C for the first time, 60s/5 times of microwave irradiation, and drying at 120°C for the second time. By the volume measurement method, the expansion coefficient of VER significantly increased compared to its initial state before modification, with the expansion coefficient increasing by 14 times. The results on the absorption capacity of expanded VER for some solvents and chemicals showed that the synthesized material has good absorption capacity for some organic solvents and chemicals, with adsorption capacities ranging from 10 to 30 times.