Camellia Panatarani

Synthesis of Single Crystalline ZnO Nanoparticles by Salt-Assisted Spray Pyrolysis

LiNO3 was used as a shield in the preparation of single crystalline ZnO particles by a spray pyrolysis process in order to prevent agglomeration and enhance the crystallinity of the ZnO. LiNO3 was added to a precursor solution of zinc acetate dihydrate prior to its atomization by means of an ultrasonic transducer. Agglomerate-free particles having a mean particle size of 26 nm were successfully obtained after washing the product. X-ray diffractometry, field-emission scanning electron micrograph and transmission electron micrograph data indicate that the size and morphology of ZnO were strongly influenced by the operating temperature used and the residence time of the particle in the reactor.

Dispersion of fine phosphor particles by newly developed beads mill

Fine phosphor Y2O3:Eu3+ particles has advanced properties compare to conventional particles applied for compact fluorescent lamp (CFL) as three band phosphor. However, suspension of fine particles easily agglomerated during preparation of spray coating of the CFL tube. Therefore, it is introduced newly developed beads mill system to disperse fine phosphor. The beads mill consist of glass beads, dispersing chamber (impellers), separator chamber, slurry pump and motors. The first important performance of beads mill is the performance of the designed on separating the beads with the suspended fine particles. We report the development of beads mill and its separation performance vary in flow rate and separator rotation speeds. The 27 kg of glass beads with 30 µm in size was poured into dispersing chamber and then water was pumped continuously through the slurry pump. The samples for the separation test was obtained every 1 hours vary in rotation speed and slurry flow rate. The results shows that the separatio...

Synthesis and Dispersion of Nanoparticles, and Indonesian Graphite Processing

Synthesis of nanoparticles and processing of nanocomposites are the essential steps in the application of nanotechnology in various industrial fields including environmental remediation and renewable energy conversion. It is very important to develop their synthesis methods in which nanoparticles having controlled characteristics including size distribution, morphologies, and compositions. Thus, the process needs to be simple, low in cost, and have both continuous operation and high production rate to meet the industrial requirements. The synthesis method for nanoparticles and the development of nanoparticles dispersion technology will be reviewed; nanoparticles synthesis by pulse combustion spray pyrolysis to improve production rate and dispersion of nanoparticles by bead mill method. Furthermore, the availability of the raw materials are also very important to produce the end products economically. The current development on the graphite processing and the future development on the end product in Indonesia will be reviewed.At the request of the authors and Proceedings Editor an updated version of this article was published on 24 September 2013. All changes are restricted to minor updating and editing of references: the scientific content of the paper remains unchanged.Synthesis of nanoparticles and processing of nanocomposites are the essential steps in the application of nanotechnology in various industrial fields including environmental remediation and renewable energy conversion. It is very important to develop their synthesis methods in which nanoparticles having controlled characteristics including size distribution, morphologies, and compositions. Thus, the process needs to be simple, low in cost, and have both continuous operation and high production rate to meet the industrial requirements. The synthesis method for nanoparticles and the development of nanoparticles dispersion technology will be reviewed; nanoparticles synthesis by pulse combustion spray pyrolysis to improve production rate and dispersion of nanoparticles by bead mill method. Furthermore, the availability of the raw materials are also very important to produce the end products economically. The current development on the graphite processing and the future development on the end product in Indone...

Purification and preparation of graphite oxide from natural graphite

Graphite oxide has attracted much interest as a possible route for preparation of natural graphite in the large-scale production and manipulation of graphene as a material with extraordinary electronic properties. Graphite oxide was prepared by modified Hummers method from purified natural graphite sample from West Kalimantan. We demonstrated that natural graphite is well-purified by acid leaching method. The purified graphite was proceed for intercalating process by modifying Hummers method. The modification is on the reaction time and temperature of the intercalation process. The materials used in the intercalating process are H2SO4 and KMNO4. The purified natural graphite is analyzed by carbon content based on Loss on Ignition test. The thermo gravimetricanalysis and the Fouriertransform infrared spectroscopy are performed to investigate the oxidation results of the obtained GO which is indicated by the existence of functional groups. In addition, the X-ray diffraction and energy dispersive X-ray spect...

Blue Luminescent of ZnO:Zn Nanocrystal Prepared by One Step Spray Pyrolysis Method

A blue luminescent of ZnO:Zn nanocrystal has been successfully prepared by one step spray pyrolysis method without reducing gas atmosphere. Zinc acetate dihydrate aqueous solutions (0.05 M) were atomized by ultrasonic atomizer. The atomizer used an air as carrier gas with 1, 3 and 5 L/min flowrate. The tubular reactor was set at 500, 600 and 700oC. As prepared samples were characterized by means of x-ray diffraction spectroscopy and scanning electron microscope-energy dispersive x-ray spectroscopy (SEM-EDS). The crystal size of as prepared particles calculated by Scherrer’s equation give 10-20 nm. The luminescent properties of as prepared particles were measured using spectrofluorophotometer. The highest photoluminescent intensity of particles irradiated with excited wavelength of 250 nm was obtained from samples prepared using 5 L/min carrier gas with temperature of tubular reactor 700oC. High intensity of blue luminescent was obtained due to oxygen vacancy in ZnO:Zn.

Microstructure Analysis of Zirconia-Alumina-Silica Particles Made from Indonesia Natural Sand Synthesized Using Spray Pyrolysis Method

Zircon sand is one of Indonesian natural resource that is potential to be used as composite filler. Natural zircon sand can be found in several places in Indonesia, i.e. Riau Islands, Bangka-Belitung, and the Borneo. Zircon sand contains zirconia compound; while ZrO2 is the oxide crystal of zirconia compound. The mechanical and esthetical supremacy of zirconia is the reason why the usage of zirconia as nanocomposite filler mixed with alumina and silica increases. Spray pyrolysis method was used to synthesized natural zircon sand of Indonesia with temperature variety of 400°C, 500°C and 600°C. Spray pyrolysis decomposed zircon sand into powder in nano-sized. Microstructure analysis conducted were SEM, EDS, and XRD. SEM analysis showed that the morphology of particle was spherical, uniform, and regular with size of 100-500nm. EDS and XRD showed best results at the temperature of 400°C. Analysis result of EDS indicated that the largest atomic percentage was owned by sodium with ratio of Zr:Al:Si of 1:2:54 at temperature of 400°C. The XRD pattern of 400°C revealed that the crystal structure of zirconium silicate (ZrSiO4) was tetragonal, the structure of quartz (SiO2) was trigonal, and the structure of corundum aluminum oxide (Al2O3) was rhombohedral. Synthesis of zirconia-alumina-silica particles from natural zircon sand of Indonesia could be used as composite filler based on the characterization results.

Preparation and characterizations of electroluminescent p-ZnO : N/n-ZnO : Ga/ITO thin films by spray pyrolysis method

ZnO thin films were fabricated by spray pyrolysis (SP) method with p-ZnO : N/n-ZnO:Ga/ITO structure. The X-ray results show that the deposited films have hexagonal wurtzite structure. The EDS results observed that the composition of Ga in ZnO:Ga and N in ZnO:N was 3.73% and 27.73% respectively. The photoluminescence (PL) with excitation wave length of 260 nm shows that ZnO:Ga and ZnO:N films emitted UV emission at ∼393 and ∼388 nm, respectively and the films resistivity was 7.12 and 12.80 Ohm-cm respectively. The electroluminescence of the p-ZnO : N/n-ZnO:Ga/ITO structure was obtained by applying forward bias of 5 volt with 30 mA current, resulting in a 3.35 volt threshold bias with the peak electroluminescence in UV-blue range.

Development and characterization of integrating sphere for photometry and radiometry measurement

Integrating Sphere (IS) is an instrument formed a cavity sphere with its inner surface act as a Lambertian reflector. IS is needed in many optical measurements which involves a high diffused reflection. In addition, IS very essential in photometry and radiometry measurement system. However, currently, IS is still an imported product which considered very expensive. The material for the sphere and inner surface coating affect the performance of the IS systems. Therefore, the main challenges in designing IS are the material engineering for the sphere and the procedure for the inner surface coating. The inner surface was coated using BaSO4 which has a low absorption and high diffuse reflection. Spectral responses of the IS system was characterized using USB2000+ and calibrated using a standard Spectralon from ocean optic. The obtained IS system used an inner surface coating from a mixed 80% Barium Sulfate (BaSO4) and 20% Nippon Elastex paint which yield a reflection factor ρ = 0.955 and amplification factor ...

Synthesis of lithium cobalt oxide using low-pressure spray pyrolysis

A low pressure spray pyrolysis (LPSP) process was applied to synthesize crystalline lithium cobalt oxide as a battery cathode material via a liquid route. The effects of temperature and pressure of reactor on the synthesized particles characteristics were systematically investigated. Reactor temperatures of 800, 1000 and 1200 °C with pressures of 760 and 300 Torr were applied as operating conditions. The characterizations results show that the synthesized particles were highly crystalline and nearly spherical in shape. The results concluded that the low-pressure spray pyrolysis method has ability in control of particles morphology, crystallinity and atomic lithium-to-cobalt ratio.

Rare earth doped on LaPO4 nanocrystal

Rare earth ions (Eu3+; Ce3+; Gd3+; Eu3+−Ce3+; and Eu3+−Ce3+−Gd3+) have been succesfully added via a simple solution phase methtod to LaPO4 nanocrystal. The nanocrystal sized of as-prepared particles calculated by Scherrer method was around 7.1 to 8.3 nm. The photoluminescent (PL) properties of particles was invesigated by means of spectrofluorophotometer LS 55. The results showed that combination of Eu3+−Ce3+−Gd3+ doped produce a highest PL peak although the addition of Gd3+ itself did not produce a significant luminescent.