SINTESIS KOMPOSIT KITOSAN-MAGNETIT TERMODIFIKASI ASAM OLEAT DAN APLIKASINYA SEBAGAI ADSORBEN Cr(III) DALAM LARUTAN BERAIR; SYNTHESIS OF CHITOSAN-MAGNETITE COMPOSITE MODIFIED BY OLEIC ACID AND THE APPLICATION AS ADSORBENT OF Cr(III) FROM AQUEOUS SOLUTION

Kurnia, Lia, Suyanta

2016 | Skripsi | FMIPA

Chitosan-magnetite composite modified by oleic acid has been synthesized by coprecipitation method and applicated as adsorbent of Cr(III) from aqueous solution. Chitosan was isolated by deproteination of utilited shrimp shells and followed by demineralization, depigmentation, and deacetylation procces. In the synthesis of magnetite modified oleic acid, solution of NH4OH 1 M was added into solution of Fe2+ and Fe3+ (molar ratio 1:2) until pH 11.5, then 3 mL oleic acid was added. Both of those materials are composited to form chitosan-magnetite composite modified by oleic acid. The adsorbent was characterized with Fourier Transform Infrared (FTIR), X-Ray Difractometer (XRD), Transmission Electron Microscope (TEM), and Vibrating Sampel Magnetometer (VSM). Chitosan has been isolated from shrimp shells with deacetylation degree was 81 %. Chitosan-magnetite composite modified by oleic acid has been succesfully synthesized and the results show that particel size of about 19.05 nm. The particel size of chitosan-magnetite composite modified by oleic acid is smaller than chitosan-magnetite composite without modified by oleic acid with the particle size of about 38.94 nm. The results suggest that the addition of oleic acid can prevent the agglomeration of the magnetite. The results showed that the optimum pH of the Cr(III) adsorption by chitosan-magnetite composite modified by oleic acid was 5. The kinetics data corelated well with the pseudo second order Ho equation with the value of rate constant (k) was 4.672 x 10-3 g/mg.min and the capacity of adsorption was 50.505 mg/g or 9.712 x 10-4 mol/g. The adsorbent of chitosan-magnetite modified by oleic acid could be removed faster by external magnet.

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