SINTESIS NANOPARTIKEL Fe3O4/SiO2 TERMODIFIKASI KITOSAN SEBAGAI ADSORBEN ION [AuCl4]-

VINANDA HAYUNING S, Dr. Roto, M.Eng.

2019 | Skripsi | S1 KIMIA

Pungut ulang logam mulia seperti Au merupakan topik penelitian yang menarik. Sintesis nanopartikel Fe3O4/SiO2 termodifikasi kitosan sebagai adsorben ion [AuCl4]- telah dilakukan. Nanopartikel Fe3O4 disintesis melalui metode sono-kopresipitasi dan dilapisi dengan SiO2 melalui metode sol-gel. Partikel Fe3O4/SiO2 kemudian dimodifikasi dengan kitosan dengan agen penghubung aminopropil trimetoksi silan (APTMS). APTMS direaksikan dengan agen taut silang glutaraldehid sebelum direaksikan dengan kitosan. Produk dikarakterisasi menggunakan spektrofotometer Fourier Transform Infrared (FT-IR), X-Ray Diffractometer (XRD), Scanning Electron Microscope-Energy Dispersive X-ray (SEM-EDX) dan Transmission Electron Microscope (TEM). Adsorpsi ion [AuCl4]-dilakukan pada berbagai pH, berat adsorben, waktu kontak dan konsentrasi awal ion [AuCl4]- dalam sistem batch. Konsentrasi ion [AuCl4]- sebelum dan sesudah adsorpsi dianalisis menggunakan Atomic Absorbance Spectrophotometer (AAS). Hasil penelitian menunjukkan bahwa adsorben Fe3O4/SiO2 berhasil dimodifikasi dengan kitosan. Data FT-IR menunjukkan puncak yang teramati sebagai yang bersesuaian dengan kitosan yang terikat dengan Fe3O4/SiO2 melalui APTMS dan gluataraldehid. XRD menunjukkan puncak difraksi dari Fe3O4 dan kitosan. Adsorben Fe3O4/SiO2/Kitosan berukuran 14 nm dengan kandungan unsur C dan N sebesar 12,7 dan 8,14 persen. Kondisi optimum adsorpsi ion [AuCl4]- tercapai pada pH 3, berat adsorben 10 mg dan konsentrasi [AuCl4]- 60 mg L-1, dan waktu kontak 540 menit. Adsorpsi mengikuti isoterm Langmuir dan kinetika orde dua semu dengan kapasitas adsorpsi maksimum 91,8 mg g-1 dan energi adsorpsi 36,6 kJ mol-1.

Recovery of precious metals like Au is an exciting topic of research. The synthesis of Fe3O4/SiO2 nanoparticles modified with chitosan for recovery [AuCl4]- ion has been performed. The Fe3O4 nanoparticles were synthesized by sono-coprecipitation method and coated with SiO2 by sol-gel method. They were modified with chitosan using aminopropyl trimethoxy silane (APTMS) and glutaraldehyde as a crosslinking agent before reaction with with chitosan. The product was characterized with Fourier Transform Infrared (FT-IR) spectrophotometer, X-Ray Diffractometer (XRD), Scanning Electron Microscope-Energy Dispersive X-ray (SEM-EDX) and Transmission Electron Microscope (TEM). Adsorption of [AuCl4]- ion was performed after optimization of media pH, adsorbent weight, contact time and initial concentration of adsorbates, which was performed in a batch system. The concentration of [AuCl4]- ions in solution before and after adsorption was analyzed with Atomic Absorbance Spectrophotometer (AAS). The results showed that Fe3O4/SiO2 nanoparticles modified with chitosan and APTMS coupling agent were successfully synthesized. The FT-IR spectra showed typical peaks for corresponding chitosan, Fe3O4/SiO2, APTMS, and glutaraldehid. The XRD data showed a specific peak of Fe3O4 and chitosan. The adsorbent has an average diameter of 14 nm with elemental C and N content of 12.7 and 8.14 persen, respectively. The optimum conditions for adsorption were reached at pH 3, the adsorbent weight of 10 mg, initial [AuCl4]- concentration of 60 mg L-1, and contact time of 540 min. The [AuCl4]- adsorption followed pseudo-second order and Langmuir isotherm model with capacity of 91.8 mg g-1 and energy of 36.7 kJ mol-1.

Kata Kunci : adsorpsi, ion [AuCl4]-, kitosan, magnetik, nanopartikel.