Advanced Materials Research Vol. 832

Abstract: The differential microemulsion polymerization was used to synthesize crosslinked latex nanoparticles. In this paper, 1, 3-butylene glycol dimethacrylate (1, 3-BGDMA) was used as a crosslinking agent respectively 0-6 weight% of monomer total. The polymerization was carried out using butyl methacrylate (BMA), butyl acrylate (BA) and methacrylic acid (MAA) as the monomer mixture. The thin film of latex nanoparticles were prepared by using spin coating method and have been dried at 100°C for 5 minutes. The amount of the crosslinking agent added in the polymerization was optimized and we found that the particle sizes fall in the range of 30-60 nm. Field Emission Scanning Electrons Microscope (FESEM) was demonstrated that the spherical image of uncrosslinked latex change to a wooden-like image when the crosslinking agent added in the polymerization.

Abstract: Titanium Dioxide, TiO₂ is one of the potential semiconductor materials. TiO₂ has much application such as for pigments, oxygen sensors, and photocatalyst. Recently, the researcher study on the other application and revealed that this material has a great potential to be use in nanocoating area. The objective of this paper is to produce TiO₂ nanostructured prepared by sol-gel method. Sol-gel was carried out using tetra (IV) isopropoxide (TTIP), absolute ethanol, Acetic Acid Glacial (GAA), Triton-X-100 and deionized water and all the solution was mixing by continuous stirring and heating. After finished prepare the sol-gel, solution will be spin coated onto glass substrate and annealed with different temperature for 2 hours. The particles were analyzed using Raman Spectroscopy to observe the crystallographic phase, and the morphology was evaluated through Atomic Force Microscopy (AFM). As a result, TiO₂ that annealed at 450°C shows the better nanostructured compared to other annealing temperature. Keywords: Titanium Dioxide (TiO₂); Sol-gel method ; Spin-coating ; Annealing process ; Raman spectroscopy

Abstract: We have produced nanocarbon suspension in pure water, which is named as Nanocaloid ^®, by a simple DC electrolysis from a synthetic graphite plates as anodes and SUS plates as cathodes in purified water at room temperature. The amount of carbon nanoparticles was monitored by the conductivity and pH value of the electrolyte solution, and also by a simple gravimetric way after drying the solution. If the current density increases, the diameter of the carbon particles becomes larger and the amount of precipitates becomes also large. It takes about six weeks to obtain about 0.4 wt% carbon suspension solution under the normal electrolysis conditions. Characterization of Nanocaloid ^® has been conducted to show unique properties and promising epoch-making applications such as solid lubricants for non-oily cutting fluids and conductive agents for reuse of deteriorated Pb-acid batteries. The performance of nanocarbon particles in oil lubricants in addition to the preparation will be reported.

Abstract: In microfluidic devices, the most important aspect has to be considered for the manufacturing process is the material suitability and geometric design. Among the materials studied, paraffin wax has never been tested and it is proposed as the new approach in this paper for patterning the microchannels. Furthermore, contact angle analysis of the paraffin wax was also studied. Based on the contact angle measurements; the hydrophobicity and surface tension of paraffin wax were analyzed. From the finding, it shows that paraffin wax has a low surface tension and high hydrophobicity. Then, several microchannels design was simulated using COMSOL multiphysics 4.2 software in order to find the optimized geometry. It involves a study of different shape, diameter, length, and angle of microchannels design, and its influence on the water flow velocity. From the simulation results, an optimize microchannels design was obtained consists of 1000 μm channels diameter, 1000 μm inlet channel length, 1.0 cm outlet channels length, and 110o inlet channel angle with water flow velocity of 2.3cm/s. Further study could be done to improve the finding of properties and geometric suitability for microfluidic device.

Abstract: Carbon nanostructures demonstrate a perfect combination of mechanical, electrical and electro chemical properties.Different approaches can improve the selectivity and sensitivity of CNT-modified electrode through immobilization of enzymes. In this research, simulation of SWCNTs attached sensor for medical application was described.Glucose oxidase was immobilized on the surface of the CNT using microencapsulation technique with non covalent bindings which has a negligible effect on the native biological activities of the enzymes. The main advantage of the Micro-encapsulation is that the entrapped particles often maintain its nature bioactivity. ABAQUS and ANSYS are the softwares which used to certify the results of experiments. Boundary conditions were selectivity detected according to the redox reaction center of enzyme and electrode surface. The results of the simulation indicate the ability of CNT to penetrate into the cells which offers the potential of using CNT as vehicles for the delivery system. Furthermore, encapsulated CNT attached sensor can work as a stress sensor simultaneously. Simulation was focused on measuring physical properties of CNTs, such as Mass, velocity, capacity and stress before and after immobilizing of GOx.

Abstract: Nanocolumnar ZnO was successfully deposited on glass substrate by RF magnetron sputtering. It was performed with a ZnO target with 99.999% purity at RF power of 200 W. The growth temperature was specified at 500°C, with total deposition time of 1 hour. The effects of oxygen gas composition during sputtering process was investigated. Argon to oxygen ratio was varied at Ar10:Ox5, Ar8:Ox7 and Ar5:x10 sccm. Optical characterization on samples indicated that the transmittance though visible range is higher than 80%. Based on morphological property obtained, higher oxygen content exhibited better uniformity and surface roughness. This is due to the reduction of oxygen vacancies in the ZnO layer.

Abstract: Nanocolumnar zinc oxide (ZnO) was deposited on glass substrates by RF magnetron sputtering.It was performed with a ZnO target at RF power of 200 W. The deposition wascarried out in argon and oxygen ambient at the ratio of 10 and 5 sccmrespectively, with total deposition time of 1 hour. The growth temperature wasfixed at 500°C and deposition pressure specified at 3, 5 and 10 mTorr. It wasobserved that the morphological and photoluminescence properties of ZnOstrongly dependent on the deposition pressure. The ZnO mean grain area was inverselyrelated with the surface roughness. The best morphological andphotoluminescence properties was found to be associated with ZnO grown at 10mTorr. Smooth ZnO surface and lowest defects related emission in PL wasobtained for the respective sample.

Abstract: This paper reports a brief outlook of carbon nanotubes (CNT) history, synthesis methods as well as natural carbon sources such as camphor powder, turpentine, eucalyptus, palm, neem, coconut, castor, olive, corn, sesame oil, palm olein, waste cooking palm oil and waste chicken fat.

Abstract: The effects of synthesis temperatures on the growth of carbon nanotubes (CNT) from waste chicken fat as carbon source were systematically studied. The synthesis was carried out in dual heating zone tube furnace at synthesis temperature between the ranges of 600-900 °C. The waste chicken fat vaporization temperature was fixed at 470°C. The samples were characterized using field emission scanning electron microscopy, micro-Raman spectroscopy and thermogravimetric analyzer. In this experiment, vertically aligned CNT (VACNT) were identified at synthesis temperature ranged of 750-800°C. Among all, the synthesis temperature of 800 °C produced highest yield of VACNT with growth rate of 282 nmmin^-1, small nanotubes diameter of 19.8-31.7 nm, 91% pure and high crystallinity (I_D/I_G ratio of 0.39). At low synthesis temperatures of 600-650°C, no CNT was produced. At high synthesis temperatures of 850-900°C, bigger nanotubes diameter and higher I_D/I_G ratio were observed which indicates lower nanotubes quality were produced at this temperature range.

Abstract: The utilization of modified electric arc furnace slag (EAFS) was successfully carried out to remove reactive dyes (SSB-BRF) from aqueous solutions. Modified EAFS was prepared and characterized by BET surface area analyzer and FESEM. The result of FESEM micrograph shows that the structure of modified EAFS has similar structure to the flower-like porous hematite (α-Fe₂O₃) nanoarchitectures composed of ultra-thin nanoflakes. Batch studies were carried out to address various experimental parameters such as adsorbent amount and concentration of dye. In the batch system, the maximum SSB-BRF uptake capacities of modified and original EAFS adsorbent (at 300 ppm dye concentration) were 80.03 and 20.99 mgg⁻¹ respectively. In the batch system for different amount of slag, the maximum uptake capacities SSB-BRF of modified and original EAFS were 92.24 and 19.08 mgg^-1 (adsorption of 300 ppm of dye concentration onto 0.1 g of slag) respectively. The Langmuir models were able to describe the adsorption equilibrium. The results indicated that modified EAFS could be employed as an excellent and low-cost sorbent for removal of reactive dye from aqueous solution.