SINTESIS DAN KARAKTERISASI KOMPOSIT SiO2-Al2O3/BENTONIT; SYNTHESIS AND CHARACTERIZATION OF SiO2-Al2O3/BENTONITE COMPOSITES

RUSLAN, Karna Wijaya

2012 | Disertasi | PROGRAM STUDI S2 ILMU KIMIA

The synthesis and characterization of SiO2-Al2O3/bentonite composites was prepared through the intercalation and pillarization of the interlayer of Na-bentonite with SiO2-Al2O3 mixed oxide sol particles. The silica-Alx(OH)y sol solution was prepared by titrating an Al3+ aqueous solution with NaOH in the presence of silica sol particles. It was then slowly added to a suspension of Na-bentonite and then the mixture was stirred and heated at 60 oC allowed to react for 3 hours. Finally, the solid was washed, dried and followed by calcined at 250 oC for 5 hours. Calcined product was then characterized to determine the chemical compound (i.e. Na, Ca, Si and Al), basal spacing, morphology, specific surface area, porosity, and surface acidity. To test its high thermal stability, the composite were calcined at 350, 450 and 550 oC for 5 hours. The test of the its acid stability, the composite were dispersed into solution of hydrochloric acid with various concentration, i.e. 1, 3 and 5 M for 24 hours. The results indicated that the intercalation and pillarization of SiO2-Al2O3 mixed oxide sol particles into the interlayer of Na-bentonite produced SiO2- Al2O3/bentonite composites with basal spacing d001 of about 0.99 nm. Its structure was obtained the meso-micropore which micropore size produced by pillared structure and mesoporous size produced by exfoliated or delaminated structure. The pillarization of SiO2-Al2O3 oxide increased the physico-chemical properties of bentonite such as surface acidity increased from 0.46 mmol/g to 2.01 mmol/g, specific surface area increased from 54.93 m2/g to 71.26 m2/g, average pore radius increased from 6.86 nm to 8.02 nm, total pore volume increased from 0.18 mL/g to 0.28 mL/g and thermal stability up to 550 oC. The acid treatment to the composites did not distore the (001) planes of bentonite

Kata Kunci : komposit; SiO2-Al2O3/bentonit; meso-mikropori; stabilitas termal dan asam