Yahmin

Bio: Yahmin is an academic researcher from State University of Malang. The author has contributed to research in topics: Particle & Specific surface area. The author has an hindex of 2, co-authored 3 publications receiving 9 citations.

Effect of Temperature Synthesis on Structural Behaviours of NaY Zeolite Using Local Sand as A Silica Source

Abstract: The purpose of this study was to synthesize NaY zeolite by utilizing local sand as a source of silica which was carried out at various crystallization temperatures. The synthesis of NaY zeolite is carried out using silica resulted from the purification of local sand while NaOH and Al2O3 are pure analysis (pa) quality. Crystallization temperature was carried out at various temperatures of 80, 100, and 150 °C. The synthesis results were characterized by physical properties, XRF, FTIR, XRD, SEM, surface area. NaY zeolite was successfully synthesized supported by FTIR data by the presence of functional groups such as Si-O, O-Al-O, Si-OH, and O-H from Si-OH, and SEM data which showed the formation of cube-shaped crystals. The formation of NaY zeolite is also strengthened by the appearance of peaks with a sharp intensity from XRD diffractogram that this zeolite is NaY and as well as data molar ratio of Si/Al is in the range of 2.027 to 2.045 respectively at various crystallization temperature. The crystallization temperature of 80 °C produces NaY zeolite better than that of crystallization temperatures of 100 and 150 °C. The synthesized NaY zeolites using local sand have a good surface area that is 658 m2/g. The crystallization temperature affects the success of NaY zeolite synthesis.

Synthesis of MgO/CoFe2O4 nanoparticles with coprecipitation method and its characterization

Abstract: This research discusses the development of magnetic materials as an effort to produce renewable catalysts in overcoming the energy crisis. The purpose of this study was to synthesize and characterize MgO/CoFe2O4 nanoparticles using the coprecipitation method. The synergy between substances that are catalysts, namely MgO and CoFe2O4 to MgO/CoFe2O4 was expected to produce a superior catalyst for biodiesel production. The stages of this research were to synthesize MgO nanoparticles and CoFe2O4 nanoparticles by coprecipitation and continued with MgO impregnation on the CoFe2O4 surface to become MgO/CoFe2O4 with a mole ratio of 5: 1, then characterize them using X-Ray Diffraction and Scanning Electron Microscopy. The results of XRD analysis showed that MgO/CoFe2O4 nanoparticles were successfully synthesized according to the standard curves of MgO and CoFe2O4 (JCPDS Cards No. 89-7746 and 22-1086). SEM analysis results show that impregnated particles have spherical morphology and are larger in size than the two constituent components. The mean particle sizes of MgO, CoFe2O4, and MgO/CoFe2O4 were 29.588 nm, 42.282 nm and 65.953 nm, respectively. EDX analysis shows the appropriate atomic percentage and mass of each of the constituents of MgO/CoFe2O4 namely Magnesium, Iron, Cobalt, Oxygen.

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.

Synthesis, Properties and Selected Technical Applications of Magnesium Oxide Nanoparticles: A Review

Abstract: In the last few decades, there has been a trend involving the use of nanoscale fillers in a variety of applications. Significant improvements have been achieved in the areas of their preparation and further applications (e.g., in industry, agriculture, and medicine). One of these promising materials is magnesium oxide (MgO), the unique properties of which make it a suitable candidate for use in a wide range of applications. Generally, MgO is a white, hygroscopic solid mineral, and its lattice consists of Mg2+ ions and O2− ions. Nanostructured MgO can be prepared through different chemical (bottom-up approach) or physical (top-down approach) routes. The required resultant properties (e.g., bandgap, crystallite size, and shape) can be achieved depending on the reaction conditions, basic starting materials, or their concentrations. In addition to its unique material properties, MgO is also potentially of interest due to its nontoxicity and environmental friendliness, which allow it to be widely used in medicine and biotechnological applications.

NaY zeolite-polyethersulfone-modified membranes for the removal of cesium-137 from liquid radioactive waste

Abstract: Isotope cesium-137 (137Cs) is a major fission product that results from nuclear processes. This radioactive material constitutes a hazardous source of contamination to the environment even at low concentrations. Removal of this harmful radioactive isotope is deemed as an intricate challenge to resolve. The present study aims to synthesize a novel NaYzeolite modified Polyethersulfone (PES) membranes for 137Cs removal from real nuclear liquid waste. The zeolite has been synthesized through hydrothermal method on seedless static aging. Various zeolite contents were then impregnated within the PES membrane matrix to modify the membrane characteristics and ion-exchange properties. Besides, the proposed interaction mechanism of the modified NaYzeolite and PES has been illustrated for the first time in this study. The characteristics of the NaY zeolite, neat PES, and modified membranes were characterized comprehensively via X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), fourier-transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), and contact angle (CA) techniques. Results disclosed that optimum removal rate (90.2%) was obtained by the membrane prepared using 0.15% NaY while the decontamination factor (DF) was 10.2 at pH 7.5. Therefore, a legend agent copper ferrocyanides (CuFC) has been added to the feed solution aiming to promote the removal efficiency of 137Cs and enhance the decontamination factor. As a result, about 99.2% Cesium retention and 121.2 decontamination factor were achieved.

Dependence of PEO content in the preparation of Fe3O4/PEO/TMAH ferrofluids and their antibacterial activity

Abstract: This work was conducted to investigate the effects of the polyethylene oxide (PEO) as a template on the structures, functional groups, magnetic properties, and antibacterial activities of Fe3O4/PEO/TMAH ferrofluids. Synthesis of Fe3O4 nanoparticles was carried out by using the co-precipitation method obtained from iron sand. The ferrofluid synthesis was done by coating Fe3O4 nanoparticles with tetramethylammonium hydroxide (TMAH) and dispersed in H2O. Based on the structural analysis, it was known that all samples had a magnetite phase with particle sizes ranging from 7.8 to 10.5 nm. The Fe3O4/PEO/TMAH ferrofluid functional groups presented appropriate bonds of Fe3O4 as a filler, TMAH as a surfactant, and H2O as a liquid carrier. The magnetic characteristics of Fe3O4 nanoparticles and Fe3O4/PEO/TMAH ferrofluids indicated the superparamagnetic state. The saturation magnetization value of Fe3O4 nanoparticles and Fe3O4/PEO/TMAH ferrofluids decreased as increasing the molecular weight of polyethylene oxide ranging from 1000 to 20,000. Furthermore, the antibacterial activities performed by the dilution method identified that increasing the molecular weight of polyethylene oxide increased the antibacterial performance of the Fe3O4/PEO/TMAH ferrofluids against Escherichia coli and Bacillus subtilis.