PENGARUH POSISI GUGUS HIDROKSI SENYAWA TURUNAN ASAM BENZOAT TERHADAP PEMBENTUKAN NANOPARTIKEL PERAK DARI AgNO3; EFFECT OF THE POSITION OF HYDROXYL GROUP ON THE BENZOIC ACID DERIVATIVE COMPOUNDS TOWARDS THE FORMATION OF SILVER NANOPARTICLES FROM AgNO3

Maghfiroh, Sri Juari Santosa

2015 | Disertasi | FMIPA

Physical character of the silver nanoparticles synthesized by AgNO3 as precursor and ortho hydroxybenzoic acid, para hydroxybenzoic acid and gallic acid as reducing agents was investigated. The aim of this study was to determine the effect of the hydroxyl group position on some derivative compounds of benzoic acid toward the morphology, size, size distribution and stability of the resulting silver nanoparticles. Synthesis of silver nanoparticles was performed using chemical reduction method with variations in the type reducing agents, reducing agents concentration, precursor concentration and pH of the system. The reduction potential of reducing agents was characterized by cyclic voltammetry method using electrochemical analyzer, the Surface Plasmon Resonance (SPR) of colloidal silver nanoparticles using UV-Vis spectrophotometer, the morphology of silver nanoparticles using Transmission Electron Microscope (TEM), while the size and size distribution of silver nanoparticles was calculated using ImageJ program version 1.48. The results showed that the potential reduction of ortho hydroxybenzoic acid, para hydroxybenzoic acid, and gallic acid was -0.4390 V, -0.5037 V, and -0.4951 V, respectively. In the formation of colloidal silver nanoparticles, an alkaline system was required for all types of reducing agent. Sensitivity reducing agents was investigated by synthesis of silver nanoparticles at various concentrations of AgNO3. Limit of detection of ortho hydroxybenzoic acid, para hydroxybenzoic acid, and gallic acid were 5.10×10-6 mol L-1, 1.24×10-6 mol L-1, dan 2.58×10-5 mol L-1, respectively. Based on TEM analysed it was known that the size of the silver nanoparticles produced by ortho hydroxybenzoic acid, para hydroxybenzoic acid and gallic acid was 93.65 ± 35.45 nm, 60.83 ± 16.99 nm, and 60.41 ± 15.69 nm, respectively. Colloidal silver nanoparticles was stored in the open space at room temperature for 6 weeks in order to investigate the stability of silver nanoparticles. The most stable of silver nanoparticles was that synthesized by para hydroxybenzoic acid, followed by that synthesized by gallic acid and that synthesized by ortho hydroxybenzoic acid.

Kata Kunci : silver nanoparticles; hydroxil group; ortho hydroxybenzoic acid; para hydroxybenzoic acid; gallic acid