SINTESIS Fe3O4@SiO2 TERMODIFIKASI PROPILDIETILENTRIAMINA SEBAGAI ADSORBEN Au(III) DARI LARUTAN HAuCl4; SYNTHESIS OF PROPYLDIETHYLENETRIAMINE-MODIFIED Fe3O4@SiO2 AS ADSORBENT OF Au(III) FROM HAuCl4 SOLUTION

Susanto, Nuryono

2015 | Disertasi | FMIPA

Synthesis of Fe3O4@SiO2 modified with propyldiethylenetriamine (Fe3O4@SiO2@PDETA) and its application as adsorbent of Au(III) from HAuCl4 solution have been investigated. Research was begun with synthesis of Fe3O4 using dispersion agent of trisodium citrate at coprecipitation system through stirring using ultrasonic wave and followed by washing using variation of solvents. Coating magnetite with propyldiethylenetriamine modified silica was carried out through sol-gel process with two different mixing sequences of raw materials (two synthesis routes) and variation of N-[3-(Trimethoxysilyl)propyl]- diethylenetriamine (TMSPDETA)/Na2SiO3 mole ratio. The products were characterized by X-ray diffraction, infrared spectrophotometer, scanning electron microscope-energy dispersive X-ray, and transmission electron microscopy. Adsorption of Au(III) on Fe3O4@SiO2@PDETA was conducted by mixing the adsorbent and HAuCl4 solution (204 ppm concentration of Au(III)) in a batch system at pH 3 for 120 minutes. Results indicate that Fe3O4 synthesized using trisodium citrate and washed with acetone-water gives smaller aggregate than that of washed with acetoneethanol. Fe3O4@SiO2@PDETA synthesized through route 1 (magnetite mixed with a mixture TMSPDETA and Na2SiO3) contains more propyldiethylenetriamine group than that of through route 2 (magnetite mixed with Na2SiO3 solution, then mixed with TMSPDETA). Increasing TMSPDETA/Na2SiO3 mole ratio inclines the capability of Fe3O4@SiO2@PDETA to adsorb Au(III). Fe3O4@SiO2@PDETA synthesized with TMSPDETA/Na2SiO3 mole ratio 2:1 shows highest capability in adsorbing Au(III) (182.179 mg/g).

Kata Kunci : Au(III); magnetite; silica modified; propyldiethylenetriamine.