The Role of Eliminating PEG from PEG/MCM-41 Composite on the Structural, Textural and Electrical Conductivity Properties of MCM-41

A PEG/MCM-41 composite was synthesized by a simple solution method with polyethylene glycol (PEG) and mesoporous MCM-41. The thermal behavior of the composite was studied using thermogravimetric analysis (TGA) and an in situ electrical conductivity measurement. The results showed that polymer degradation occurs in the temperature range of 300 to 550 °C, and is accompanied by a decrease in the electrical conductivity. Thus, to elucidate the influence of polymer elimination on the structural, textural and electrical conductivity properties of MCM-41, a sample was prepared by calcining the PEG/MCM-41 composite for 3 h at 550 °C in air. Various physico-chemical techniques such as XRD, FT-IR, FE-SEM and N2 physisorption, were used for characterization. It was shown that the calcined solid still exhibits the mesoporous MCM-41 framework with poor ordering. A texture analysis revealed that the PEG/MCM-41 composite formation and the subsequent PEG elimination are accompanied by a loss of the type IV character of the MCM-41 and a sharp decrease in the textural parameters. The observed meso-porosity loss of the MCM-41 as a result of adding and then eliminating the PEG molecules was accompanied by a reduction of the conductivity.