Study of the ethanolic tributylmethylammonium aluminosilicate solutions using 27Al NMR

Alkaline solutions containing both silicate and aluminate ions are of considerable research interest inter alia because of their involvement in the synthesis of zeolites. In the present work, we use 27Al NMR to characterize alkaline aqueous and ethanolic tributylmethylammonium aluminosilicate solutions with different Al/Si ratios. Tributylmethylammonium (TBMA) used as a cation template and no alkaline metals are used for preparation of aluminosilicate solutions. Aluminum-27 NMR spectra of TBMA aluminosilicate solutions indicate that considerable changes occurred by changing the Si/Al ratio. The distribution of aluminosilicate species was affected by the presence of the methanol and the method of mixing the silicate and aluminosilicate solutions. To understand the reaction between silicate and aluminate ions in this system, the evolutions of 27Al NMR spectra with time are investigated.