Advanced Materials Research Vol. 667

Abstract: Zingiber officinale Roscoe, family of Zingiberaceae is classified as traditional medicinal that globally consumed as spices, food flavouring as well as remedies to treat women during confinement, to treat stomach upset and diarrhoea.The rhizome has been reported to contain abundant bioactive constituents which are mainly polyphenol and flavonoid. Therefore in this research the effect of cabinet drying (60°C) and freeze drying (-40°C) process during preparation of nanostructure Zingiber officinale Roscoe rhizome on particle sizes, surface morphology, FTIR, as well as Total Phenolic Content (TPC) and Total Flavonoid Content(TFC) were compared. Both drying process affect the particle sizes as well as TPC and TFC value. Finer particle size (254.3+ 9.33) and higher TPC (152.54 mg GAE/ g) and TFC (1.42 mgQE/g) were reported for cabinet dried nanostructure Zingiber officinale Rosc. rhizome as compared to freeze dried. The FESEM Photographs revealed that drying processes did affect the surface morphologies of nanostructure Zingiber officinale Rosc rhizome where cabinet dried produced solid spherical particles with a diameter around 100 – 200 nm and some smaller than100nm. Freeze dried consist of many nanoparticles having rod like structure. Both drying process did not significantly affect the presence of active compounds based on FTIR analysis.

Abstract: In this paper, carbon nanotubes were characterized by several characterization methods such as FESEM (field emission scanning electron microscopy), Raman spectroscopy and fourier transform infrared (FTIR) spectroscopy. FESEM is used to characterize the morphology of carbon nanotubes, the structural is characterize by raman spectroscopy and bonding characteristic is determine by FTIR. The morphology of CNTs is found to be multiwall carbon nanotubes with diameter around 30-50 nm. D-peak was observed at 1341 Cm-1 and G-peak at 1575 Cm-1 based on raman spectroscopy result. The chemical bonding observed at range 2400 - 400 from FTIR spectra. These CNTs will be used for in vitro study in future.

Abstract: Amorphous carbon (a:C) were successfully deposited on the silicon surfaces via bias assisted pyrolysis-CVD in the range between 350oC to 500oC with constant of negative bias -50V in 1 hour deposition. The heated of palm oil at about 150oC was vaporized then used for deposited onto p-type silicon substrates. The deposited thin films were characterized by using field emission scanning electron microscopic (FESEM), energy dispersive analyser x-ray (EDAX). We have found carbon element at about 0.15 keV from EDAX with surface morphology formed a nano-ball like structure at 450oC of palm oil precursor. These results indicated deformation of physical and structural thin films caused by applied negative bias and the temperature.

Abstract: In this paper, carbon nanotubes on porous silicon substrate were developed in order to get high quality nanotubes for various kind of application. CNTs were deposited on porous silicon nanostructures (PSiN) at 750 0C on porous silicon by using double-furnace thermal chemical vapor deposition technique. Align carbon nanotubes with diameters of 15 to 30 nm were successfully synthesized on a porous silicon substrate. In this system, carbon nanotubes were grown directly on the p-type porous silicon surface at 750 0C for a total time of 30 minutes. The samples were characterized using field emission scanning electron microscopy and micro-Raman spectroscopy. Align carbon nanotubes (ACNTs) bundle with uniform diameter (~20 nm) were found grown on porous silicon at certain area. Based on micro-Raman spectroscopy result, the peak of silicon at ~520 nm and peak of carbon nanotube (around 1 300 to 1 600 nm) was detected.

Abstract: The effects of nanoclay on the thermal stability and decay resistance properties of tropical wood polymer nanocomposites (WPNCs) were investigated in this work. WPNC were prepared from several selected tropical wood species by impregnating the selected woods with a combination of nanoclay and phenol formaldehyde (PF) prepolymer mixture. The formation of WPNC was confirmed by the fourier transform infrared spectroscopy (FTIR) analysis. Thermal property of manufactured WPNC in terms of thermogravimetric analysis (TGA) was evaluated, and an improvement in thermal stability was found for fabricated WPNC. The wood was then exposed to two types of fungi; white-rot (polyporous versicolor) and brown-rot (postia placenta), for 12 weeks. Decay was assessed through percentage (%) of weight loss. A significant improvement was found in the treated woods compared to the untreated ones. In addition, the fabricated WPNC showed lower moisture content compared with raw one.

Abstract: In this investigation, it was successfully shown that variation of heating media for infused substrates in precursor solution, affects the growth density and size of nanostructured ZnO rods. ZnO rods were prepared by precipitation on a template of cleaned p-type silicon wafer, sputter-coated with a thin layer of gold, infused in prepared precursor solution. The precursor solution consists of 0.01M zinc nitrate hexahydrate (Zn(NO3)2.6H2O) added with equal concentration of stabilizer hexamethylenetetramine, C6H12N4 (HMTA). The set-up was heated in water-bath or dry-oven at a constant low temperature of 80°C. Structural images of the prepared ZnO rods were captured using scanning electron microscope (SEM), its structural phase orientation was characterized by x-ray diffraction (XRD) and its optical property was analyzed from photoluminescence (PL) emission spectra.

Abstract: In this work, ZnO thin films were deposited by RF Magnetron sputtering at different substrate temperatures in the range of 100-400oC on glass substrate. The thin films were characterized using field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and I-V measurement, for morphology and electrical properties study. Field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM) were used to study the structural and morphology of the thin films. The particle size varied from 41nm to 146nm showing that the nucleation of ZnO thin films as the substrate temperatures increased. Higher particle size was observed as the substrate temperatures increased up to 400oC as well as high conductivity of thin films at 400oC.

Abstract: The effect of precursor concentration ranging from 0.1 to 0.5 M using the mixture of zinc nitrate hexahydrate (Zn(NO3)2.6H2O) and urea (CH4N2O) at 60 oC evaluated in this study. ZnO nanostructures have been prepared by solution immersion method on gold-seeded silicon substrate (Si/Au). Solution immersion method was adopted with the intention to develop a large area deposition at low-temperature benign method of preparation. As concentration increase, the morphologies are seemingly changed from rod (~300 nm) to accumulated nanosheets that consist of many pores. The structural and optical effect of changing the precursor concentration on the synthesization of ZnO films were investigated by X-ray diffractometer (XRD) and room temperature photoluminescence (PL) measurement, respectively. A unique development of size and growth orientation is seemingly affected by the change of the precursor concentration.

Abstract: Aluminum (Al) doped Zinc Oxide (ZnO) thin films were prepared using sol-gel spin-coating method at different doping concentrations. The effects of Al doping concentration at 0~5 at.% on the Al doped ZnO thin film properties have been investigated. The thin films were characterized using Current-Voltage (I-V) measurement and field emission scanning electron microscope (FESEM) for electrical properties and surface morphology, respectively. The I-V measurement result indicated electrical properties of Al doped ZnO thin film improved with Al doping. The FESEM investigations show that the nanoparticles size becomes smaller and denser as the doping concentration increase.

Abstract: The properties of nanostructured aluminum (Al) doped zinc oxide (ZnO) thin film for thin film transistors (TFT) are presented. This research has been focused on optical and structural properties of Al doped ZnO thin film. The influence of Al doping concentration at 0~5 at.% on the Al doped ZnO thin film properties have been investigated. The thin films were characterized using UV-Vis-NIR spectrophotometer for optical properties. The surface morphology has been characterized using field emission scanning electron microscope (FESEM). The absorption coefficient spectra obtained from UV-Vis-NIR spectrophotometer measurement show all films have low absorbance in visible and near infrared (IR) region but have high UV absorption properties. The calculated Urbach energy indicated the defects concentrations in the thin films increase with doping concentrations The FESEM investigations shows that the nanoparticles size becomes smaller and denser as the doping concentration increase.