Showing papers by "Adrian Nur published in 2018"

The Current Density on Electrosynthesis of Hydroxyapatite with Bipolar Membrane

Abstract: Synthesis of hydroxyapatite by electrochemical method was has been successfully done. The novelty of this research is used of the bipolar membrane to separate electrolysis chamber. The bipolar membrane is used to keep the cations still around the cathode and react to form hydroxyapatite. The aim of this paper was to compare the current density on electrosynthesis of hydroxyapatite with and without bipolar membrane and the effect of current density on electrosynthesis. The electrosynthesis was performed at 2 hours at 400 to 600 mA/cm2 at room temperature. The bigger the current density, the more pure HA formed. The electrosynthesis of hydroxyapatite with bipolar membrane more effective than without bipolar membrane. The formation of HA is very effective in the cathode chamber. HA can be formed at low current density. In electrosynthesis with the bipolar membrane, particles of HA are nanosheet flower-like. The nanosheet flower-like HA growth at 1.6 A to 2 A.

Synthesis of Fe3O4 Nanoparticles using PEG Template by Electrochemical Method

Abstract: One of the nanoparticles which have been developed is magnetite. Due to its magnetism and reactivity, this particle can be used in various fields including technology, environment, and biomedical. One simple method to synthesize magnetite is electro-oxidation of iron in the water. The particle size produced by this method can be adjusted by controlling the electrochemical cell parameters. Unfortunately, this method usually releases polydispersed particles. One solution to overcome this problem is by using an in situ PEG in the synthesis process. In this research, PEG 6000 was chosen as a template, so the synthesis process was performed by electro-oxidation of iron in the dilute solution of PEG. Particles with an average diameter of 62.5 nm were obtained. The monodispersity, surface area, and crystallinity of the particles increased in this way. The specific surface area increased from 55.322 to 391.314 m2/g. The results of XRD and FTIR analysis showed that PEG acted as a template in the synthesis process. In addition, the yield obtained with PEG template was larger than without the template. This method is quite promising as a way of synthesis of magnetite nanoparticles.

Tin recovery from tin slag using electrolysis method

Abstract: The process in industry, including in mining industry, would surely give negative effect such as waste polluting to the environment. Some of waste could be potentially reutilized to be a commodity with the higher economic value. Tin slag is one of them. The aim of this research was to recover the tin contained in tin slag. Before coming to the electrolysis, tin slag must be treated by dissolution. The grinded tin slag was dissolved into HCl solution to form a slurry. During dissolution, the slurry was agitated and heated, and finally filtered. The filtrate obtained was then electrolyzed. During the process of electrolysis, solid material precipitated on the used cathode. The precipitated solid was then separated and dried. The solid was then analyzed using XRD, XRF and SEM. The XRD analysis showed that the longest time of dissolution and electrolysis the highest the purity obtained in the product. The SEM analysis showed that the longest time of electrolysis the smallest tin particle obtained. Optimum time achieved in this research was 2 hours for the recovering time and 3 hours for the electrolysis time, with 9% tin recovered.

Sintesis hidroksiapatit berukuran nano dengan metode elektrokimia dibantu EDTA

Abstract: EDTA-assisted synthesis of nanosized hydroxyapatite by electrochemical method. Synthesis of nanosized hydroxyapatite by electrochemical method has been studied. The aim of this work is to study the effects of variuos parameters on hydroxyapatite particles. The electrochemical synthesis was prepared in solution Ca 2+ /EDTA/PO 4 3 at concentration 0.25/0.25/0.15 M. The solution was electrolized by using constant direct current at certain current density. There were two treatments for particles after electrosynthesized, namely without aging or aged for 3 days at 40 o C. For both cases, the particles were filtered and washed by demineralized water to eliminate the impurities and unreacted reactans. Then, the particles were dryed at 40 o C for 2 days. The dryed particles were characterized by X-Ray diffraction, surface area analyzer, scanning electron microscopy, Fourier transform infrared spectra and thermogravitimetric and differential thermal analysis. The results showed that nanosized hydroxyapatite were produced by electrochemical method. The produced particles were composed of needle-like or plate-like morphologies with equivalent diameter 19-143 nm. The produced particles diameters were inversely proportional to current density, duration of electroysis and EDTA concentration, and proportional to the distance between two electrodes and temperature. The product calcium phosphates types depended on the final pH of electrolysis process and aging treatment. It would tend to hydroxyapatite if pH>8 and brushite if pH 8 cenderung membentuk HA, sedangkan pH<8 cenderung membentuk fasa brushit . Kata k unci :hidroksiapatit, nanopartikel, elektrokimia, sintesis, karakterisasi

Catalytic performance of heterogeneous Rh/C3N4 for the carbonylation of methanol

Abstract: The excess of water in homogeneous the carbonylation of methanol system could increase the amount of by-products formed through water-gas shift reaction and could accelerate the rusting of equipment. Many scientists tried to decrease the content of water in the carbonylation of methanol system by using lithium and iodide promoter that results a moderate catalytic activity in the water content at 2wt%. The heterogenized catalyst offers several distinct advantages such as it was enables increased catalyst concentration in the reaction mixture, which is directly proportional to acetic acid production rate, without the addition of an alkali iodide salt promoter. The heterogeneous catalyst also results in reduced by-product formation. This study is aimed to produce a novel catalyst (Rh/C3N4) with a high selectivity of acetic acid in a relatively lower water and halide content. This novel catalyst performs high conversion and selectivity of acetic acid as the result of the strong ionic bonding of melamine and r...

The electrolysis time on electrosynthesis of hydroxyapatite with bipolar membrane

Abstract: The electrochemical method with bipolar membrane has been successfully used for the synthesis of hydroxyapatite. In this work, we have developed 2 chambers electrolysis system separated by a bipolar membrane. The membrane was used to separate cations (H+ ions produced by the oxidation of water at the anode) and anions (OH− ions produced by the reduction of water at the cathode). With this system, we have designed that OH− ions still stay in the anions chamber because OH− ions was very substantial in the hydroxyapatite particles formation. The aim of this paper was to compare the electrolysis time on electrosynthesis of hydroxyapatite with and without the bipolar membrane. The electrosynthesis was performed at 500 mA/cm2 for 0.5 to 2 hours at room temperature and under ultrasonic cleaner to void agglomeration with and without the bipolar membrane. The electrosynthesis of hydroxyapatite with the bipolar membrane more effective than without the bipolar membrane. The hydroxyapatite has been appeared at 0.5 h ...

Synthesis of ZnO/CuO Composite by The Electrochemical Method in The Acetat Acid Solution

Abstract: The metal oxide composite is used to the microelectronic circuit, piezoelectric, fuel cell, sensor, catalyst, coating for preventing corrosion, and solar cell. The ZnO/CuO is one of the metal oxide composites. The combination of ZnO and CuO is the potential composite used to the catalyst and the anti-bacterial agent. The method used in this research was the electrochemical method in the acetate acid solution. The acetate acid solution used in this research is cheaper than the succinite acid used in the previous research. The electrochemical method has advantages due the easy to control and cheap. The composite resulted was analyzed by the XRD and the FTIR. The aims of this analysis are to know the crystallite phase, structure, and the functional groups of the particle resulted. The analysis showed that the ZnO-CuO composite can be resulted by the electrochemical method.