Nghiên cứu ảnh hưởng của tỷ lệ tiền chất/ammoniac đến cấu trúc vật liệu chứa nanosilica

Abstract

This study aimed to determine effect and relation between tetraethyl orthosilicate precursor (TEOS) and NH₃ catalyst for nanostructured silica preparation through condensation method, based on their molar ratio. The nanostructured silica was prepared in mixed solution of NH₃, ethanol, water with previous given calculations. The preparation was established at room temperature for 12 hours followed by filtering the as-synthesized precipitate. The precipitate was then dried and calcinated at 120 ^oC for 12 hours and at 600 ^oC for 3 hours, respectively for the final nanosilica containing products. A series of nanosilica containing samples were studied based on the molar ratios of TEOS/NH₃, and the sample with the finest morphology was chosen for further characterizations. As the obtained results, the chosen sample with TEOS/NH₃ of 1.5/1 existed in amorphous phase with particle size ranging from 12 nm to 25 nm. Some techniques were used such as SEM, TEM, EDX, FT-IR and UV-Vis for characterizing the morphology, element percentage, functional groups and silica absorption band respectively of the as-synthesized material.