Preparation of amine functionalized silica by the one-step in spray drying system

Abstract Amine functionalized silica has been successfully prepared using a direct co-condensation method in spray-assisted with sodium silicate as silica source and γ-aminopropyltriethoxysilane (APTS) as amine source. This study aims to synthesize amine grafted silica in one step process which includes particle formation and surface modification. Silica-amine nanofluids were prepared in stable colloidal phase as precursor solution for spray drying system. Amine sourced from APTS was condensed separately with silica nanofluids. The process of controlling the condensation rate of APTS can prevent the occurrence of silica precipitates in the precursor. The silica-amine precursor solution was then processed by spray drying at a temperature of 200°C. Silica particles that have been modified by amine groups were characterized using FT-IR, TG-DTA, and Adsorption-desorption N2. The silica-amine showed the presence of an amine group that was successfully grafted. This is indicated by the presence of characteristic amine peaks on FT-IR and mass changes due to amine decomposition in TG-DTA. The number of amines that were successfully grafted was 0.5 mmol/g sample. The washing of amine-modified silica particles with ethanol showed that the type of bond that occurred between silica and the amine functional group was a physical bond. The surface area of amine-modified silica is 169 m2/g with the pore size distribution in the micro-mesopore regime. The average pore size of amine-modified silica was 0.1288 nm.