Advanced Materials Research Vol. 1087

Abstract: In this study, TiO₂ nanoparticles were successfully synthesized using sol-gel technique by employing different mixing routes. The nanoparticles were characterized for field emission scanning electron microscopy, energy dispersive X-Ray spectroscopy, Fourier transformed infrared, Raman spectroscopy, x-ray diffraction and ultraviolet visible spectroscopy. It is apparent that different mixing sol-gel route significantly influenced the morphology, crystallite structure, particle and crystal size and band gap of TiO₂, under similar molar ratio. The differences in physicochemical and optical properties of synthesized TiO₂ greatly influenced its photocatalytic activity in reactive black 5 dye degradation. In overall, mixed crystal structures of anatase and rutile showed better photocatalytic activity for the degradation of reactive black 5 dye due to a narrower band gap, as opposed to single phase TiO₂.

Abstract: Cellulosic materials derived from pineapple leaves fibers (PALF) which are being wasted after fruit harvested. There are two methods to extract cellulose from PALF. First methods were using sodium hydroxide (NaOH) 2% for alkaline treatment and bleached by sodium hypochlorite (NaClO) and buffer. Second method, cellulose was extracted using peroxyacetic acid delignification and bleached the sample in acidified pH 3 hydrogen peroxide solution. From X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) data’s, it is proven that both samples of cellulose have shown cellulose I structure.

Abstract: Treated palm oil fuel ash waste was used as substitution materials for silica in in order to fabricate mullite ceramic. Alumina powder was added into the treated palm oil fuel ash in order to supply a deficient alumina component according to the alumina/silica molar ratio of mullite. Mullite phase was successfully achieved upon sintering at temperature above 1220 oC besides other minor impurities, such as perovskite, Al₂O₃ and SiO₂. The surface of samples becomes smoother as the sintering temperature increased to 1270 oC whilst forming closed pore morphology. Besides that, the hardness of the samples increased as an increasing in the sintering which is attributed not only to the full densification of pores on the surface, but also due to the presence of mullite phase.

Abstract: X-ray diffraction (XRD) and energy dispersion spectroscopy (EDS) analysis has been conducted on composite cathode powder LSCF-SDCC-Ag. Composite cathode powder LSCF-SDCC has been produced using high energy ball milling via wet milling method through calcinations at 750 °C. The calcined LSCF-SDCC powder then was mixed with Ag (3wt%) then pressed become pellets and sintered at 500, 550 and 600 °C. The phase purity of composite cathode powder LSCF-SDCC-Ag was determined via XRD analysis and elements distributions were observed via EDS-mapping. The SrCO₃ phase was emerged after the addition of composite cathode powder LSCF-SDCC with Ag powder. The phase purity of composite cathode powder LSCF-SDCC-Ag were maintained before and after sintered. The variable of sintering temperature also not effect the structure as there were no other secondary constituent emerged as confirmed by XRD sensitivity. EDS analysis shows LSCF-SDCC-Ag produced via ball milling has uniform distribution of elements.

Abstract: Anodic oxidation is an electrochemical method for the production of ceramic films on a metallic substrate. It had been widely used to deposit the ceramic coatings on the metals surface. In this study, the surface morphology and crystallinity of titanium foil was modified by anodising in mixture of β-glycerophosphate disodium salt pentahydrate (β-GP) and calcium acetate monohydrate (CA). The experiments were carried out at high voltage (350 V), different anodising time (1, 3, 5 and 10 min) and current density (10 and 20 mA.cm^-2) at room temperature. Anodised titanium was characterised by using glancing angle X-ray diffraction (GAXRD), field emission scanning electron microscope (FESEM) and focused ion beam (FIB) milling. The result of the experiment show that colour, porosity, crystallinity and thickness of the titanium films depended strongly on the current density. More porous surface and large amount of anatase was produced at higher current density. FIB results indicated that the thickness of oxide layer increased as increasing of current density.

Abstract: Nanostructured Fe-TiO₂ and TiO₂ with anatase structure were synthesized via combination method of sol-gel and peptization process. The samples were characterized by X-ray diffraction (XRD), Transmission emission microscopy (TEM) and UV-Vis spectroscopy (UV-Vis). The presence of Fe³⁺ ion shifted the absorption profile of TiO₂ to the longer wavelength side of the spectrum, indicating an obvious photocatalytic activity under visible irradiation. Photocatalytic activity of the samples were evaluated by methyl orange (MO) discolouration under UV-light irradiation. Compared with the pure TiO₂ nanoparticles, the Fe-TiO₂ nanoparticles exhibited higher photocatalytic activity with 95% discoloration within 2 h.

Abstract: Pb (Zr_0.52Ti_0.48)O₃, (PZT) powder has been synthesized using high energy ball milling technique. The synthesized powders were characterized using XRD, SEM, Density, Porosity and Impedance Analyzer. XRD patterns show that the perovskite phase of PZT can be formed from the mixture of starting material after milling for 40 h. The grain sizes of the powder have been estimated to be 1-3 μm. The relationship between the microstructure of the PZT samples and sintering temperature has been discussed. Dense PZT (> 95 % theoretical density) with excellent dielectric properties was obtained when the pellet are sintered at higher temperature with shorter soaking time. The results show that the sample sintered at 1100 °C /1 h yields a clearly uniform grain size with the highest dielectric constant.

Abstract: Corrosion is a serious problem in every industry and can cause losses in production leading to large financial losses. International legisation body has drawn offshore chemical into several categoris based on biodegradation, bioaccumulation and toxicity. Otherwise, the inhibitor is not accept to be used as they are harmful to environment. Therefore, most industries are looking for green inhibitor for An electrochemical test has been carried out to determine the corrosion rate of carbon steel. This research aimed to investigate the potential corrosion of carbon steel in seven different immersion periods ( 1 day, 2 days, 7 days, 14 days, 21 days , 28 days, 35 days) using seawater 3.5 % NaCl. The pH values were set in neutral in static condition. The materials were run for tafel polarization with a scan rate of 0.5mV/sec. Each sample will be tested when achieve a predetermined time. This experiment was carried out to compare the corrosion rate of 3.5% NaCl and with NaCl added 25% inhibitor. Inhibitors used were from banana trunk. The experiments were carried out at four different temperatures (5°C, 10°C, 20°C and 30°C). Before and after testing, the microstructures of each sample were observed by using Optical Microscope (OM). The results show the highest corrosion rate occurring in the shortest period of immersion for 1 day. However, the corrosion rate decreases when the longer period of immersion. The corrosion rate for 3.5% NaCl will increase with added 25% inhibitor and decrease for 3.5% NaCl when temperature decreases.

Abstract: Foam replication method is capable of producing foams with a highly porous structure with adjustable pore dimension, shape and size. In this work, this method has been used to prepare stainless steel 316L foam and sintered at 1200°C, 1250°C and 1300°C in a vacuum furnace. The microstructure and elemental analysis of the sample were examined using scanning electron microscope (SEM) and Energy Dispersive X–Ray (EDX), while the mechanical properties of the samples was determined by using compression test. It was found that the average pore size was in the range of 330µm-350µm. The yield strength and elastic modulus are in the range of 58-66 GPa and 0.46-0.50GPa respectively.

Abstract: Refractory gold ore understudied showed traces amount of gold from X-ray fluorescence analysis. Phases identified are quartz, muscovite and calcite. Statistical approach using response surface methodology - central composite design were performed at varying concentration of NaCN, Pb (NO₃)₂ and H₂O₂. Cyanidation experiments were conducted at room temperature at pH 11. Using the response surface methodology followed by path of steepest ascent, gold cyanidation was found to be at 467.3 ppm NaCN, 94.96 ppm Pb (NO₃)₂ and 0.01M H₂O₂, at the vicinity towards the optimum condition where 88.97% Au extracted from the ore, equivalent to 1.7231 g/t Au.