Adrian Nur

Electrochemical synthesis of nanosized hydroxyapatite by pulsed direct current method

Synthesis of nanosized of hydroxyapatite (HA) by electrochemical pulsed direct current (PDC) method has been studied. The aim of this work is to study the influence of various PDC parameters (pH initial, electrode distance, duty cycle, frequency, and amplitude) on particle surface area of HA powders. The electrochemical synthesis was prepared in solution Ca2+/EDTA4−/PO43+ at concentration 0.25/0.25/0.15 M for 24 h. The electrochemical cell was consisted of two carbon rectangular electrodes connected to a function generator to produce PDC. There were two treatments for particles after electrosynthesized, namely without aging and aged for 2 days at 40 °C. For both cases, the particles were filtered and washed by demineralized water to eliminate the impurities and unreacted reactants. Then, the particles were dried at 100 °C for 2 days. The dried particles were characterized by X-ray diffraction, surface area analyzer, scanning electron microscopy (SEM), Fourier transform infrared spectra and thermogravimetr...

Synthesis of Fe3O4 Nanoparticles using PEG Template by Electrochemical Method

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.

The electrolysis time on electrosynthesis of hydroxyapatite with bipolar membrane

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 ...

Phase Control of TiO2 Prepared by TiCl4 Hydrolysis and Electrochemical Method

The phase structure of TiO 2 dependent on applications. It is importat to develop an effective method to control the phase structure of TiO 2 . In this study, the TiO2 was synthesized by TiCl 4 hydrolysis method. The control of hydrolysis was done by electrochemical method in a cell consisting of two plate carbon as electrodes. The electrodes distance was set to 2.6 to 4 cm and immersed in solution at dimensions of (5 × 2) cm. The electrodes were connected to the positive and negative terminals of a DC power supply for 1 to 2.5 hours. The voltage was varied from 5 to 15 V at constant stirring and room temperature. The resulted suspension was aged for 48 hours. The solution was filtered. The powder dried directly in an oven at 150°C for 2 hours, washed 2 times, and dried again 60 °C for 6 hours. In this work, the voltage, electrode distance, and TiCl 4 initial concentration can control the phase structure of TiO 2 .