Preparation of aminopropyl functionalized silica fiber for adsorption of formaldehyde in water

Abstract

The silica fibers can be applied for adsorption of formaldehyde which had been classified as a carcinogen in human. In this study, silica fibers were fabricated by electrospinning technique via sol-gel process. Many factors that affect the morphology of electrospun fibers including the distance between syringe needle and collection screen, as well as electric potential were studied. The optimized distance and electric potential were 10 cm and 15 kV, respectively. The diameter of the needle of 0.8 mm and flow rate 20 µL/min were selected for the optimum condition for preparation of electrospun silica fibers. The Scanning Electron Microscope (SEM) images illustrated that most of silica fibers were smooth and straight with diameters in the range of 200-270 nm. For preparation of functionalized silica fibers, 3-aminopropyltriethoxysilane (APTES) was used for aminopropyl functionalization. Characterization with thermogravimetry, surface area analysis, elemental analysis and Infrared spectroscopy showed the clear difference between aminopropyl functionalized on electrospun fibrous silica mats and non-functionalized electrospun silica fibers. It could conclude that aminopropyl group could be successfully grafted on electrospun silica fibers. Using 0.15 M APTES for functionalization of silica fibers with APTES and subsequent adsorption of formaldehyde in water for 3 hours were the optimum method. In the part of elution, the optimum condition was using hydrochloric acid or sulfuric acid with concentration of 0.1 M and elution for 15 minutes.