Suminar Pratapa

• Prof.
• Professor (Full) at Sepuluh Nopember Institute of Technology

The crystal and local structures of nanocrystalline undoped and CaO-doped ZrO2 were investigated using hightemperature synchrotron X-ray powder diffraction (XRD) and X-ray absorption spectroscopy (XAS). Nano­crystalline ZrO2 was synthesized via a co-precipitation method, whereas CaO-doped ZrO2 was prepared through mechanochemical wet milling, using...

This study explores the structural and optical properties of zircon (ZrSiO4) and zirconia (ZrO2) nanopowders using two types of natural Indonesian zircon sands. The former powders were synthesized through dissolution and non-dissolution methods, while the latter powders were synthesized using alkali fusion and co-precipitation techniques. x-ray flu...

The structural analysis of the CaO-ZrO2 solid-solutions was carried out using in-situ synchrotron radiation X-ray diffraction (SR-XRD). CaO-ZrO2 solid-solutions with 0, 2.5, and 5 at.% CaO contents were synthesized via a solid-solid ball milling technique. The amorphous ZrO2 powder was synthesized via co-precipitation using ZrCl4 and NH4OH as precu...

Phase formation and structure examination has been conducted to study the effects of thermal treatment and heating rates on zircon (ZrSiO4) sand-derived zirconia (ZrO2). A preliminary investigation of the elements present in the sand using XRF revealed that Zr was the major element, corresponding to 92.4% of the sample. The zirconia precursor was s...

Activation energy and crystal growth coefficient of t-ZrO2 (tetragonal zirconia) were determined through an in-situ synchrotron radiation X-ray diffraction (SR-XRD) experiment. The tZrO2 precursor was synthesized through (a) purification of zircon sand from Kereng Pangi, Kalimantan to zircon powder, (b) alkali fusion, and (c) co-precipitation. High...

Kegiatan pengabdian kepada masyarakat ini dilakukan dalam rangka membantu meningkatkan efisiensi pertanian jagung petani poktan LMPSDH Wonodadi di lahan Hutan Wonodadi, Lembeyan, Magetan yang selama ini umumnya masih menggunakan cara tradisional sehingga kurang efisien dari segi tenaga, waktu dan biaya. Kegiatan dilakukan dengan merancang mesin ter...

Rice husk is an agricultural waste rich in carbon and silica contents. So far, no studies have been reported that simultaneously transform it into polymorph silica and activated carbon. This study aims to analyze the thermal event and identify the phase, functional groups, and microstructure of the silica and activated carbon derived from a rice hu...

Abstrak Pengajaran optika dalam kurikulum SMA/MA sering kali menjadi tantangan bagi siswa, terutama dalam pemahaman konsep optika fisis. Salah satu faktor utama yang berkontribusi pada kesulitan ini adalah keterbatasan pengetahuan guru dalam melakukan praktikum mengenai interferensi dalam optika fisis. Hasil dari diskusi dengan guru-guru SMA/MA jug...

Zircon‐filled poly(methyl methacrylate) (PMMA) composites were synthesized, and their physical properties after ambient heat treatments were investigated. The sub‐micron zircon filler was obtained by purifying local zircon sand. The heat treatments were at 25°C (untreated), 55°C, and 70°C, around the glass transition temperature of PMMA. The crysta...

Ultra-high-density zircon (ZrSiO4) ceramics were prepared using the spark plasma sintering (SPS) technique of zircon nanopowder with the addition of three different sintering agents, i.e., Bi2O3, V2O5 and B2O3. The effect of each agent and the SPS parameters (temperature and pressure) on phase composition, microstructure, thermal and mechanical pro...

Produksi buah kelapa Indonesia rata-rata 15,5 miliar butir/tahun, setara 3,02 juta ton kopra, 3,75 juta ton air, 0,75 juta ton arang tempurung, 1,8 juta ton serat sabut, dan 3,3 juta ton debu sabut. Sabut kelapa merupakan hasil samping dari buah kelapa yang berpotensi cukup besar. Saat ini pemanfaatannya masih belum optimal bahkan cenderung menjadi...

Powders of lithium iron phosphate (LFP) with Cu doping and carbon coating were prepared by a dissolution method using Fe sourced from natural ironstone. Two dopant amounts were used, 2 and 3 at.% while the carbon coating used carbonization with 9 wt.% citric acid. Synchrotron X-ray diffraction (XRD), Fe K-edge X-ray absorption spectroscopy (XAS), a...

The thermomechanical and optical properties of poly(methyl methacrylate) (PMMA)/quartz and PMMA/zircon composites at filler content variations of 0, 1, 2.5, and 5 wt% have been studied. The silica quartz and zircon powders were derived from local sands collected from Tanah Laut, South Kalimantan, and Kereng Pangi, Central Kalimantan, Indonesia, res...

The synthesis of zircon (ZrSiO4) powders was optimized through the variation of puya sand mass and HCl molarity reduction. This study aimed to produce zircon powder in large quantities more efficiently. The puya sand was obtained from Kereng Pangi, Central Kalimantan, Indonesia. The zircon powders were synthesized through the process of mesh 40 sie...

Kemampuan siswa dalam analisis dan pemecahan masalah merupakan aspek-aspek penting dalam pembelajaran fisika. Akan tetapi keterbatasan alat praktikum untuk mendemonstrasikan konsep fisika serta ketidaktepatan metode pembelajaran sering kali membuat siswa merasa kesulitan dalam menguasai aspek tersebut. Oleh karena itu, kegiatan pelatihan praktikum...

The thermomechanical properties of polyethylene glycol (PEG) composites filled with various zircon sizes were studied. The zircon powders were derived from natural (well‐known as puya) sand collected from Kereng Pangi, Central Kalimantan, Indonesia. The effects of the zircon size and content were examined to understand the thermomechanical properti...

Various LiFePO4 (LFP) powders with natural ironstone as a base material were prepared using the dissolution method. They were synthesised using different (a) calcination temperatures, (b) milling times, and (c) Cu doping concentrations. X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX), tran...

Solar Cell Research Group, which is under Advanced Materials Research Group, Department of Physics, Faculty of Science and Data Analytics, ITS Surabaya, with its competency and research, tries to be actively involved in contributing and providing alternative solutions to problems in society, especially regarding the problem of global warming an...

Micro-quartz-reinforced - polyethylene glycol (PEG) composites were fabricated by a simple liquid method. This study reveals the thermomechanical properties of the PEG/quartz composites around its melting transition temperature. The quartz microparticles were prepared from natural silica sand collected from Tanah Laut Pelaihari, South Kalimantan, b...

This study aimed to determine the tensile strength and strain properties of poly(methyl methacrylate) (PMMA)/nano-zircon (n-ZrSiO4) composites with various nano-zircon sizes. Wet milling method for 5 and 15 h without annealing treatment was used to obtain the nano-zircon powders. Results showed that milling for 15 hours can reduce zircon size up to...

The effect of tetragonal‐zirconia nanoparticle inclusion on the temperature‐dependent storage modulus, or the temperature‐degradation rate, of polyethylene glycol (PEG)‐based composites was investigated using shear‐mode dynamic mechanical analysis (DMA) at temperatures ranging from room temperature up to 75°C. We carried out further investigations...

This work described an experimental investigation of the synthesis in high-purity zircon (ZrSiO4) powders from zircon sand by varying the processing procedure. The zircon powder was obtained from natural zircon sand taken from Kereng Pangi, Central Kalimantan. The sand was subjected to sieving (mesh 40) and planetary ball milling for 2h. Impurities...

Nano-zircon-reinforced poly (methyl methacrylate) (n-Z/PMMA) composites were prepared using a liquid mixture approach and their tensile storage moduli were investigated using a dynamic mechanical analyzer (OMA). The effect of the n-Z concentration, i.e., 1, 2.5, and 5 wt%, on the storage moduli of the PMMA-based composites was the focus of this wor...

Synthesis of zircon solid ceramics with the addition of B2O3 as a sintering agent has been carried out using the Arch Plasma Sintering (APS) method. The raw zircon powder was prepared from local zircon sand. The zircon and the B2O3 powders were milled for 1 hour at a speed of 150 rpm. The amount of B2O3 was varied at 0, 3, and 6 wt%. The conditions...

As excellent alternatives for cleaner energy production evaluated against conventional nonrenewable energy sources, fuel-cells have now been commercially viable. However, efforts to improve their efficiency are always important. By high temperature and sandwich model of fuel-cells, sealing materials play an important role to prevent air leakage and...

Synthesis of ZnO nanostructures films by a co-precipitation followed by the deposition processed onto a glass substrate by spin-coating technique was carried out. The effect of annealing temperatures (from 250 to 325 °C for 30 min) on the structural and optical properties of the ZnO films have been investigated. The structural studies reveal that Z...

The Al–Mg–Si composites employing aluminum (Al) as matrix, magnesium (Mg) and silicon (Si) as fillers with weight ratio of 60 : 20 : 20 have been prepared by the method of powder metallurgy. The mixed powders were pressed applying pressure of 700 MPa, followed by sintering at 500, 550, and 600°C for 3 h in inert atmosphere. The resulted samples hav...

Despite the importance of reducing production costs, investigating the hierarchical nanostructure and magnetic field ordering of Fe3O4 ferrofluids is also important to improve its application performance. Therefore, we proposed an inexpensive synthesis method in producing the Fe3O4 ferrofluids and investigated their detailed nanostructure as the ef...

This article aims to report on the production of precipitated CaCO₃, with various morphologies and particle sizes through several methods, namely carbonation methods with CO₂ gas bubbling, rapid mixing of the solutions, and carbonation with modified bubbling techniques. The simple bubbling method was performed by flowing CO₂ gas into Ca(OH)₂ soluti...

Effect of defect - through observation of energy absorption Urbach, on deposition rate, energy band gap, and surface roughness of intrinsic thin film are investigated using Radio Frequency Plasma Enhance Chemical Vapor Deposition (RF-PECVD). Films are grown on ITO (Indium Tin Oxide) glass substrate. Analysis of energy band gap is conducted to deter...

The synthesis of Fe2TiO5 powders has been successfully performed by making use of Fe2O3 and TiO2 powders. The Fe2O3 powder was obtained from local ironstone in Tanah Laut, South Kalimantan, while the TiO2 powder was a commercial product. The Fe2O3 powder was obtained from the local ironstone through coprecipitation method on pH 5, followed by calci...

Polyethylene glycol (PEG)/quartz (denoted as BP/Q) composites have been investigated as candidates of phase change materials (PCMs) due to their thermomechanical properties around the glass transition temperature as well as thermal properties between 30 and 600 °C. Quartz (q‐SiO2) powders were extracted from local sand in Tanah Laut, Pelaihari, Sou...

In this study, a temperature-dependent storage modulus model is described and then implemented in polyethylene glycol (PEG)/silica composite systems. The study began by investigating the performance of four available models in predicting the storage modulus as a function of the temperature. Then, the best performing model, based on the simulations...

The structural characteristics of polymorphic raw material combinations of silica-zirconia powder systems were investigated through X-ray diffraction (XRD), Wide-angle X-ray scattering (WAXS), Fourier transform infrared (FTIR), and X-ray absorption near edge structure (XANES). Stoichiometric mixtures (1:1 mol% ratio) of silica (SiO 2 : amorphous an...

Data in this article presents the dynamic thermomechanical properties of PEG/amorphous-silica composites with different silica content, i.e. 0, 20 and 40% by weight. These composites were prepared using a solid-state method. The morphology of the amorphous-silica filler powder was determined using the transmission electron microscopes (TEM). Furthe...

Effect of hydrogen dilution on deposition rate, energy band gap, localized state defect - through observation of energy absorption Urbach, and surface roughness of intrinsic thin film was investigated using RF-PECVD. Films were grown on ITO glass substrate. Analysis of energy band gap was conducted to determine changes in the structure of a thin fi...

The effect of silica polymorphs on the thermomechanical properties of 0, 5, 10, and 20 wt % silica particles‐reinforced‐based poly(ethylene glycol) (PEG) composites have been studied as a function of temperature using dynamic mechanical analysis (DMA). The silica polymorphs exhibited quartz (Q), cristobalite (C), and amorphous (A) phases, which wer...

High-purity zircon (ZrSiO4) nanopowder was successfully produced from Indonesian natural zircon sand using a low-cost purification approach via magnetic separation, immersion in HCl, and reaction with NaOH, followed by a top-down nanosizing process using wet ball-milling for 10 h and annealing at 200 °C for 2 h. Furthermore, polymorph zirconia (ZrO...

Poly(ethylene) glycol (PEG)/ZrSiO4 composites have been prepared and their thermomechanical propertis have been characterized using a dynamic mechanical analyzer (DMA). PEG 4000 was used as the matrix and a ZrSiO4 powder, extracted from puya sand Kereng Pangi, Central Kalimantan, was used as the filler. ZrSiO4 weight fractions of 0, 5, 10 and 20% w...

Quartz-sand/corundum composites have been successfully produced by a simple solid-state reaction approach. The composites with corundum weight fractions of 10%, 20%, and 30% were prepared through grinding mixtures of purified Indonesian quartz sand and commercial high purity corundum for a half-hour with an addition of 3% polyvinyl alcohol. The com...

Kelompok Penelitian Material Sel Surya, merupakan bagian dari Kelompok Penelitian dan Laboratorium Bahan Maju, Departemen Fisika, FIA, ITS Surabaya, berusaha untuk berperan aktif, dan menjadi bagian yang tidak terpisahkan dari seluruh upaya dunia untuk mengatasi krisis energi dan pemanasan global, melalui penelitian dan pengembangan energi terbaruk...

This work reported the investigation on the effect of relaxation to the permittivity (' r) characteristic of Mg1-x Zn xTiO3 ceramics for x = 0 – 0.5 (MZT0 – MZT0.5) measured from 1 Hz to 330 MHz. Within that frequency range, the relaxation effect that consists of the space charge (SC) and the dipolar (D) polarization mechanisms were identified. The...

XANES analysis has been performed with the aim of knowing the Fe oxidation state in a synthesized LiFePO4 and its base materials. XANES measurements were performed at SLRI on energy around Fe K-edge. An XRD analysis has also been performed with the aim of knowing the phase composition, lattice parameters and crystallite size of the LiFePO4 as well...

Electricity problem of most small islands in Indonesia has become a serious problem and need to be immediately resolved. In this present paper, Kangean Islands, Sumenep district of Madura, Indonesia, is one of the most suitable islands for an example. In this island, the existing electricity supply is mainly generated by diesel generators. Even tho...

Intrinsic hydrogenated amorphous silicon (i-a-Si:H) flms were successfully grown on commercial glass substrate by plasma enhanced chemical vapor deposition (PECVD), using various hydrogen dilutions (R = H 2/SiH). Deposition was carried out at a substrate temperature of 270 °C, using radiofrequency power of 5 W, and chamber pressure of 2 Torr. The d...

Nanopowders are defined as powders having particle size less than 100 nanometers. Due to the specific surface effect, they have unique and different properties from powders with larger particle size. The quality of nanopowders extremely depends on the purity and homogeneity of the grain/crystallite size. These factors are associated with the comple...

This paper reports the synthesis and structural, microstructure, and dielectric characterizations of nanosized forsterite powders and their ceramics. Forsterite powder was synthesized by the mechanical activation of starting materials magnesium oxide (MgO) and amorphous silica (SiO2) powders followed by calcination at 950°C. The amorphous silica po...

Manganese (Mn)-doped black iron oxide (Fe3O4) magnetic fluids in the system of MnxFe(Formula presented.)O4 were successfully synthesized from natural magnetite (iron sand) by using co-precipitation method at room temperature. The analyses of the small angle neutron scattering (SANS) data by applying a log-normal sphere with a mass fractal models fo...

Synthesis and thermomechanical characterization of polyethylene glycol-silica cristobalite composites have been successfully performed. Commercial Polyethylene glycol (PEG) 4000 and natural-silica-sand-derived cristobalite (SiO2) powders were used in this research. The cristobalite ceramic powder was produced by a coprecipitation method using silic...

Silikon amorf terhidrogenasi (a-Si:H) adalah salah satu material sel surya yang sangat menjanjikan, karenajika dibandingkan dengan kristal silikon (c-Si) material ini mempunyai absorpsivitas yang lebih besar dengankebutuhan material yang lebih sedikit (tipis). Sehingga diharapkan dapat mereduksi biaya produksi dan hargasel surya. Tetapi sampai saat...

One of many applications of spinel ferrite nanoparticles is related to their performance as radar absorbing materials. In this work, we report developing synthesis method through combined coprecipitation-sonochemical routes in preparing Zn0.5Mn0.5Fe2O4 nanoparticle from iron sand in Indonesia as a vital raw material. The structure, size, morphology...

An attempt has been developed to establish the prospect of the useful application of Indonesian natural silica sand, instead of commercially expensive materials, as a future fuel-cell sealant. The sand was initially washed and ball-milled at 150 rpm for 60 minutes and then heated at 1000 °C for the same duration. The resulting powder was then mixed...

The effects of SiO2-ZrO2 polymorphic combinations as starting powders and calcination temperature on phase composition of the SiO2-ZrO2 composites were studied. Stoichiometric (1:1 mol%) mixtures of the SiO2-ZrO2 composites were mechanically activated using a ball-milling for 5 h followed by calcinations at 1000, 1100 and 1200 °C for 3 h. The compo...

Degradation activation energy of PEG-Cristobalite composites was investigated using Dynamic Mechanical Analysis (DMA) instrument at multi-frequency shear mode. The applied frequencies were 1, 10, 100, and 200 Hz. The cristobalite of as much as 20% and 40% by weight was used as the filler of the composites, while PEG 4000 was the matrix. Results sho...

Nanoparticles of Fe3O4 have been successfully synthesized using a simple coprecipitation technique from natural iron sands, employing HNO3 and NH4OH as dispersing and precipitating agents, respectively. The substitution of Fe with Mn to result in Fe3-xMnxO4 (0 ≤ x ≤ 3) was conducted to control the magnetic strength of this nano‐sized spinel powder....

Boria (B2O3)-added forsterite (Mg2SiO4) ceramics were synthesized and their properties were characterized. The addition of B2O3 was aimed to produce high density forsterite ceramics at a low sintering temperature. The raw materials were purified silica sand and commercial magnesia powders. Fosterite powder was produced from a solid reaction between...

Zircon powders have been produced from raw materials of amorphous zirconia and amorphous silica powders obtained from natural zircon sand of Kalimantan Tengah, Indonesia. Synthesis process was started with the extraction of zircon powder to produce sodium silicate solution and pure zircon powder. The amorphous zirconia and silica powders were prepa...

The degradation activation energy of PEG-quartz composites has been determined using Dynamic Mechanical Analyser (DMA) data by varying the frequency in the shear mode. Frequencies of 1, 10, 100, and 200 Hz were applied. The content of quartz (SQ) as the filler was 0, 20, 40 wt.%. DMA measurement results showed that the addition of quartz improved t...

Synthesis of LiFePO4/C composites has been carried out using a sol gel method. The Fe precursor was made from a natural iron stone of Tanah Laut, South Kalimantan, while the other raw materials were commercial Li2CO3 powder and NH4H2PO4 powder with HCl and water as solvents. Citric acid was used as the carbon source in the synthesis. This study use...

In this study, we have investigated polymorphic silica (SiO2) powders using, Wide Angle X-ray Scattering (WAXS) and X-Ray Absorption Near Edge Spectroscopy (XANES), laboratory X-Ray Diffraction (XRD) instruments. The WAXS and XANES spectra were collected using synchrotron radiation at Synchrotron Light Research Institute (SLRI), Nakhon Ratchasima,...

Lapisan intrinsik Si:H ini terdiri dari 2 lapis, dan ditumbuhkan pada kaca ITO (Indium Tin Oxide) menggunakan metode PECVD (Plasma Enhanced Chemical Vapour Deposition) tanpa doping melalui variasi pengenceran hidrogen R=H2/SiH4 pada temperatur substrat 270oC, daya RF 10 watt, dan tekanan chamber 530 mTorr. Lapis pertama, ditumbuhkan dengan pengence...

Has done an intrinsic thin layer deposition of hydrogenated amorphous silicon (a-Si: H), the layer of a-Si: H without doping through variations in hydrogen liquefaction R = H2 / SiH4 using PECVD (Plasma Enhanced Chemical Vapour Deposition). Layer grown on glass ITO (Indium Tin Oxide). Analysis bandgap energy conducted to determine changes in the st...

A series of Mg1−x Znx TiO3, x = 0–0.5 (MZT0–MZT0.5) ceramics was synthesised and characterised. The dielectric properties of the samples in the frequency range of 1 Hz–7.7 GHz were explored using three different methods: a contacting electrode method, a parallel-plate method and a perturbed resonator method. The electrical properties in the space c...

In this work, nano-sized ZnO powders have been synthesized by the co-precipitation method with Zn(CH3COOH)2.2H2O, HCl, and NH3.H2O as raw materials in various pH ranging from 8 to 10. The purity, microstructure, chemical group analysis, morphology of the prepared ZnO powders were studied by X-ray diffraction (XRD), Fourier transform infrared spectr...

Synthesis of microforsterite (Mg2SiO4) has been successfully done by a simple method benefiting of the local silica sands from Tanah Laut, Indonesia. The starting material was amorphous silica powder which was processed using coprecipitation method from the sands. The silica powder was obtained from a series of stages of the purification process of...

Nano-forsterite powder with natural silica sand and magnesium powder as the raw materials have been succesfully synthesized. The silica sand was purified followed by a coprecipitation process to obtain colloidal silica. The magnesium powder was dissolved in a chloric acid solution to obtain MgCl2 solution. The nanoforsterite powder was synthesised...

Zinc oxide powders have been synthesized by a co-precipitation method at low temperature (85 °C), using zinc acetate dihydrate, ammonia, hydrochloric acid solutions as the reactants. A number of process parameters such as reaction temperature, solution basicity or pH and heating time are the main factors affecting the morphology and physical proper...

Nano-forsterite powder with natural silica sand and magnesium powder as the raw materials have been succesfully synthesized. The silica sand was purified followed by a coprecipitation process to obtain colloidal silica. The magnesium powder was dissolved in a chloric acid solution to obtain MgCl2 solution. The nanoforsterite powder was synthesised...

A carbonation method has been applied to induce the precipitation reaction of calcium carbonate powders with unique morphology. The reaction was strongly influenced by temperature, pH, CO2 gas flow rate and flow duration. Characterization of the as-prepared CaCO3 by XRD and SEM demonstrated that the vaterite phase was mostly formed at low temperatu...

A synchrotron small-angle X-ray scattering (SAXS) study on PVA/Fe3O4 magnetic hydrogels has been performed to investigate the effect of clustering on their magnetic properties. The hydrogels were prepared through freezing–thawing (F–T) processes. The structure, morphology and magnetic properties of magnetite (Fe3O4) nanoparticles (NPs) were investi...

A study to enhance the value of natural silica sand from Tanah Laut, South Kalimantan, Indonesia has been initiated. A number of local sands were selected as the candidates for the study. The selected sand contained more than 90% quartz and was further processed to obtain a high purity initial powder using magnetic separation and immersion with HCl...

Natural sand-based magnetite nanoparticles have been successfully synthesized by coprecipitation method at room temperature. Magnetite nanoparticles were investigated by X-ray diffractometer (XRD), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM). Qualitative analysis of XRD data reveals that the structure of magnetit...

Ferrofluid (magnetite/Fe3O4 magnetic fluid) is colloidal suspension containing Fe3O4 nanoparticles dispersed in a liquid carrier. In this work, Fe3O4 particles in the fluid have been prepared by a simple co-precipitation route. The nano-structural behaviors such as phase purity and crystal structure of magnetite particles in ferrofluid were studied...

Natural sand-based magnetite nanoparticles have been succesfully synthesized by coprecipitation method at room temperature. Magnetite nanoparticles were investigated by X-ray Diffractometer (XRD) and Vibrating Sample Magnetometer (VSM). The morphology of magnetite nanoparticles has been evaluated by Transmission Electron Microscopy (TEM). Qualitati...

A study of liquid mixing route to synthesize high purity Mg0.8Zn0.2TiO3 nanopowder, a candidate dielectric ceramics, has been successfully performed. Formation of the phases on the dried powder was studied using TG/DTA, XRD and FT-IR data. Rietveld analysis on the collected XRD patterns confirmed the formation of solid solution in the system. Such...

The complex shear modulus of polyethylene glycol (PEG) 4000 + quartz compositesas a variation of processing temperature and applied temperature has been investigated using a Dynamic Mechanical Analysis (DMA) instrument. The quartz, obtained by processing silica sand from Tanah Laut, South Kalimantan, of as much as 40% by weight was used as the fill...

Seal is one of the most important components in fuel cells which is required to bond the cell stacks and prevent mixing of gases in electrodes. Some of the requirements for such components are able to seal several adjacent cell components, which means compatible in thermal expansion coefficient values, and need to be chemically stable in a long-ter...

A prospective fuel cell sealing material using silica sand from Bancar, Tuban, East Java has been investigated. The investigation was aimed to enhance the value of such natural sand and was started by a treatment using magnetic separation and immersion with HCl to produce pure silica powder. Ceramic composites were then synthesized by a solid state...

Ferrofluid (magnetite/Fe3O4 magnetic fluid) is colloidal suspension containing Fe3O4 nanoparticles dispersed in a liquid carrier. In this work, Fe3O4 particles in the fluid have been prepared by a simple co-precipitation route. The nano-structural behaviors such as phase purity and crystal structure of magnetite particles in ferrofluid were studied...

Natural sand-based magnetite nanoparticles have been successfully synthesized by coprecipitation method at room temperature. Magnetite nanoparticles were investigated by X-ray diffractometer (XRD), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM). Qualitative analysis of XRD data reveals that the structure of magnetit...

Natural sand-based magnetite nanoparticles have been successfully synthesized by coprecipitation method at room temperature. Magnetite nanoparticles were investigated by X-ray diffractometer (XRD), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM). Qualitative analysis of XRD data reveals that the structure of magnetit...

The formation of geikielite (MgTiO3, abbreviated as MT) nanomaterial with an addition of polyethylene glycol (PEG)-1000 during synthesis is reported. The synthesis of MT was carried out by means of the dissolved-metal mixing route with PEG-1000 as a template. Prior to the synthesis, Mg and Ti powders, as the raw materials, were independently dissol...