Rapid synthesis of aluminium polycations by microwave assisted hydrolysis of aluminium via decomposition of urea and preparation of Al-pillared montmorillonite

The aim of this work is to provide a new efficient method of preparation of aluminium polycations/oligomers, and especially [AlO4Al12(OH)24(H2O)12]7+ (Al13). The microwave assisted forced homogeneous hydrolysis of aluminium through breakdown of urea (M–Al–Urea) is studied and compared with aluminum hydrolyzed with OH− ions (C–Al–OH). M–Al–Urea solutions are characterized by UV–Visible (‘Ferron’ kinetic assay) and 27Al NMR spectroscopies. Al13-sulphate precipitated from M–Al–Urea and C-Al-OH solutions are studied by XRD, TGA and SEM. Al-pillared montmorillonites are prepared with M–Al–Urea solutions as pillaring agent and characterized by XRD, BET, SEM-EDS, TGA and ATR techniques. The advantage of M–Al–Urea solutions as pillaring agent when compared to C–Al–OH is highlighted in the present study.