Pengaruh Konsentrasi Asam Terhadap Karakter Silika Gel Hasil Sintesis dari Natrium Silikat
ABSTRACT: In this research,
synthesis and characterization of silica
gel from sodium silicate through sol-gel process using H2SO4, HCl, and citric
acid have been investigated. Synthesis was carried out by mixing and stirring 20 mL of H2SO4, HCl or citric acid at certain concentration with 50 mL of sodium
silicate solution (Na2O 0.17 M and SiO2 0.61 M) for one hour and let to form
gel. The gel was washed with distillated
water, and dried in an oven at 100oC. Characterization of silica gel
was carried out by determination of acidity, water adsorption capacity, and
water content. Identification of functional group and structure were identified
using x-ray diffractometer (XRD) and infrared (IR) spectrophotometer,
respectively.
Results showed that at a range of investigated concentration (0.6 – 3.0
M) the increase of concentration, formation of gel with H2SO4 tended to be
faster, but with HCl and citric acid to be slower. The increase of acid
concentration caused water content, water adsorption capacity, and acidity of
the silica gel resulted with HCl and citric acid tended to be increased,
increased, and increased, but with H2SO4
to be decreased, increased, and decreased, respectively. Based on the IR
spectra and XRD data, it could concluded that the synthetic silica gels
contained silanol (Si-OH) and siloxane (Si-O-Si) and were amorphous, showing
similar pattern to kieselgel G 60 produced by Merck.
Penulis: Nuryono and Narsito
Kode Jurnal: jpkimiadd050018