27Al MAS-NMR study of inorganic polymer formation at ambient temperature

Abstract Inorganic polymers are a novel class of materials formed by the polymerization of silicon, aluminium and oxygen species to form an amorphous three-dimensional framework structure. The basis of this process is the alkaline solutions to induce a certain amount of Si and Al atoms to dissolve from a feedstock such as aluminosilicate. A study of 27 Al MAS-NMR was carried out in an attempt to understand the reaction mechanism of the inorganic polymerization at ambient temperature. Scanning electron microscopy (SEM) and X-ray diffractometry (XRD) were also employed to establish the composition and microstructure of the inorganic polymerization. Specimens were prepared with different Al/Si mole ratios from the starting materials. The higher the Al content, the more sufficient the Al atoms that can combine with SiO 4 , and the longer the reaction time, the more the bonded Si-O-Al-O polymer structure, and then the higher the Al content, the fewer the octahedral Al with a uniform Si-O-Al-O structure in four directions, because four Al atoms are combined with SiO 4 , resulting in a uniform Si-O-Al-O structure in four directions. The results show that they have an amorphous microstructure.