Figure 6
29Si MAS NMR of batch reactions at a solution:solid ratio of 10:1. Asterisks denote spinning side-bands. For the fully reacted sample (t = 8 d), the two signals at δ = -81 ppm and -85 ppm are due to bridging and non-bridging Q2 Si-O-Al and Si-O-Si linkages, respectively. The two signals at δ = -92 ppm and -96 ppm are due to branching Q3 Si-O-Al and Si-O-Si bonds, respectively.