Materials Science Forum Vol. 840

Abstract: Polymethylvinylsiloxane (PMVS) were prepared by pre-hydrolysis/condensation of several silicon compounds: methylvinydichlorosilane (MVDCS) and dimethyldichlorosilane (DMDCS) followed by catalysis equilibrium copolymerization by dibutyltin dilaurate (DBTDL). All manipulations in the experiments were performed under ambient condition. The PMVS were characterized by Fourier transform infrared spectroscopy (FTIR). This method has provided information about the structure of the polymer. The ¹³C NMR techniques give two sets of carbons at 1.77 ppm and 136.0 ppm consist of signals from carbons of both ligand groups, whereas ²⁹Si NMR signals of the-22.49 ppm and-35.98 ppm region are due to silicon sites bearing the methyl and vinyl ligand groups; the ²⁹Si signals of the - 109 ppm region are due to silicon sites without ligand groups attached.Keywords: Polymethylvinylsiloxane, copolymerization, NMR

Abstract: The high temperature phase transition of zirconia produced from commercial zirconyl chloride chemical was compared with that produced from a Malaysian zircon mineral. Zirconyl chloride was produced from zircon by using the hydrothermal fusion method. Initial XRD diffractogram of these samples at room temperature show that they are of amorphous structure. High temperature XRD studies was then performed on these samples; heated up to 1500°C. The XRD diffractograms shows that the crystalline structure of tetragonal zirconia was first observed and the monoclinic zirconia becomes more visible at higher heating temperature.

Abstract: The reduction behaviour of 3% cerium doped (Ce-Fe₂O₃) and undoped iron oxide (Fe₂O₃) by hydrogen in nitrogen (10%,v/v) and carbon monoxide in nitrogen (10%,v/v) atmospheres have been investigate by temperature programmed reduction (TPR). The phases formed of partially and completely reduced samples were characterized by X-ray diffraction spectroscopy (XRD). TPR results indicate that the reduction of Ce doped and undoped iron oxide in both reductants proceed in three steps reduction (Fe₂O₃ → Fe₃O₄ → FeO → Fe) with Fe₃O₄ and FeO were the intermediate. TPR results also suggested that by adding Ce metal into iron oxide the reduction to metallic Fe by using both reductant gaseous give better reducibility compare to the undoped Fe₂O₃. The reduction process of Ce and undoped Fe₂O₃ become faster when CO was used as a reductant instead of H₂. Furthermore, in CO atmosphere, Ce-Fe₂O₃ give complete reduction to metallic iron at 700 0C which about 200 0C temperature lower than other samples. Meanwhile, XRD analysis indicated that Ce doped iron oxide composed better crystallite phases of Fe₂O₃ with higher intensity and a small amount of FeCe₂O₄.

Abstract: This paper investigates the properties of Sago pith waste ash (SPWA) from agricultural waste using different calcination temperatures (500°C, 700°C and 1000°C). Chemical characteristic of SPWA was first investigated by using X-ray fluorescence (XRF) followed by XRD analysis as a verification of the mineralogical phases present in the SPWAs. Based on the analysis, the major compositions of SPWA are found to be CaO and SiO₂ with other minor oxides such as MgO, Fe₂O₃ and Al₂O₃. Both CaO and SiO₂ are very significant oxides that can be used as an alternative binder in the synthesis of ceramic materials and geopolymer. Moreover, the presence of these oxides are consistent for SPWA calcined from 500°C, 700°C and 1000°C. Phase transformation such as quartz, calcite and magnesite that can be found in 500°C and 700°C whilst new phases such as wollastonite, fayalite and cristobalite in 1000°C proved that SPWA beneficial to be used as a new material resources especially in the ceramic and geopolymer applications.

Abstract: The reserach is focused on the resistance of bio-polymer thin film to bio-degradation in compost soil from renewable resources based on waste banana peel and waste egg shell in polymer matrix. The combination of waste banana peel and waste egg shell in producing of bio-mulching film is a new inovation in agricultural industry . Bio-mulching film is a biodegradable plastics films that can help in increasing the moisture content of soil and improving the soil ingredients in order to make the plants grow well. The thin film is produced by using the waste banana banana peelas the reinforcement fiber, eggshell as filler and epoxy resin as matrix. The thickness of thin film was in between 0.10 mm to 0.15 mm. The epoxy/waste banana banana peelwith eggshell (EWE) 10%, were affected by bio-degradation in soi burial test where the occurances of surface damages, which in turn enhances the degradation of physical properties.

Abstract: This study aims to characterize and investigate properties of EAF slag waste obtained from Southern Steel Berhad, Penang (one of Malaysia’s largest steel makers), prior to its recycling into valuable products. Before characterization, lump form of the EAF slag was crushed into micron size powder. The properties investigated were loss of ignition (L.O.I.), chemical composition, leaching behavior, thermal properties and mineral phases present. Through XRF characterization, the chemical composition of the EAF slag was obtained. The slag was found to have extremely low L.O.I. (0.01 wt.%). Leaching test proved the slag is non-hazardous and safe to be handled. Meanwhile, thermal analysis (TGA) revealed the EAF slag is thermally stable and unlikely to decompose upon heating. Phase identification and quantification were performed by applying Rietveld refinement method. The EAF slag consisted of gehlenite (Al₂O₃.2CaO.SiO₂ – 45.3 wt.%), larnite (2CaO.SiO₂ – 21.0 wt.%), hematite (Fe₂O₃ – 13.4 wt.%) and wustite (FeO – 20.3 wt.%) mineral phases. The XRD profile fitted well with agreement indices of the refinement (R_wp: 6.658 and GOF: 2.588). The properties investigated in this study are expected to shed lights in evaluating the potential recycling of the EAF slag into various valuable products such as aggregate, brick, ceramic tile and cementing material.

Abstract: Supported imidazolium-based ionic liquids (ILs) were developed for adsorption/desorption studies of carbon dioxide. ILs could be easily immobilized into silica support materials using sol-gel method. The developed materials were successfully characterized using XRD, TGA, DTA, and BET analysis. The CO₂ adsorption/desorption measurement were carried out using temperature-program-desorption technique and proved that the supported ILs on silica could reduced the temperature of CO₂ desorption from 750 to 390 °C. The best performance for CO₂ sorption (1.17 mmol CO₂/g adsorbent) was achieved with 1-ethyl-3-methylimidazolium hydrogensulfate [EMIm][HSO₄]-silica system.

Abstract: Accurate quantification of uranium and thorium elements was performed in the absence of standards for the XRF analysis. This quantification method uses standard addition method. The standard addition method was first established by performing a micofocus XRF onto a sample. In the calibration graphs of uranium, the R² was 0.9997 white the R² value for thorium was 0.9915. Once the baseline quantity of both uranium and thorium were obtained, they were used to normalize all the quantification of other samples prepared by grab and vibratory methods. It was found out that the vibratory method gives more accurate results.

Abstract: Ca (OH)₂ sorbent with novel pods bundle structure were successfully synthesized by precipitation method by using Cetyltrimethylammonium bromide (CTAB) as cationic surfactant. The effects of CTAB on the morphologies of Ca (OH)₂ sorbent were investigated. The results showed that the presence of CTAB could significantly differ the shape and particle size of the Ca (OH)₂ sorbent which synthesized in ethanol media at 35°C for 30 minutes. The XRD pattern indicated that the as-prepared product were well-crystallized hexagonal phase of Ca (OH)₂ sorbent. Possible mechanisms for the CTAB assisted particle growth of Ca (OH)₂ sorbent are discussed. The Ca (OH)₂ sorbent have been studied by thermal gravimetric analyzer (TGA) at a 650oC carbonation temperature. The morphological changes and particle size of the sorbent have greatly influenced the CO₂ capture performance.

Abstract: Iron oxide (α-Fe2O3) as adsorbent was no longer new in CO2 adsorption studies. However, its contributions in the industry still in limited wherein lack of convincing results of quantifying of adsorbed CO2. This work presents an analysis for α-Fe2O3 was prepared by simple mixing method with identified the adsorption capacity that applied in CO2 capture. The synthesized α-Fe2O3 from different concentrations of precursor were analyzed using XRD, N2 adsorption-desorption isotherms with BET and BJH method, TEM, FTIR, CO2 adsorption at 298 K, CO2-TPD and TGA-DTG. It was noted that 2M concentration of precursor (s2M) with highest crystallite peaks shows highest surface area among all samples which indicative of well generated pores. The different concentration of precursor was found generated more porosity rather than particle size according to TEM micrograph. The sphere shape crystallite particle with high surface area (50.5 m2/g) and porosity were desirable properties in CO2 adsorption. Consequently, physically adsorbed CO2 with adsorption at 298 K was highest with adsorption capacity of at 17.0 mgCO2/gadsorbent. Finally, chemically adsorbed CO2 was successfully identified from CO2–TPD analysis with adsorption capacity of 0.19 mgCO2/gadsorbent and 1.31 mgCO2/gadsorbent at maximum desorption temperature of 375 °C and 749 °C respectively.