Determination of Synthesis of Silica-Based Quaternary Ammonium Material Using ²⁹Si CP/MS NMR and XPS

The synthesis of silica-based quaternary ammonium material was investigated by using 29Si CP/MS NMR and XPS. The XPS wide scan spectra dominate by the C 1s and N 1s, except for Si 2s, 2p and O 1s, the N 1s core-level spectrum is curve-fitted with peak signals about 401.26 eV, attributable to the R4N+, which indicates quaternary ammonium is bonded onto surface of silica gel. The grafting yield is about 0.46 mmol/g by TGA-DTA analysis. Forming mechanism of grafting was investigated by 29Si MAS/CP, the structural and reaction route were obtained.