Advanced Materials Research Vol. 832

Abstract: The use of low-cost adsorbent derived from agricultural waste has been investigated for the removal of Cd (II) from aqueous solution. This research reports the feasibility of using solid pineapple waste (SPW), sugarcane bagasse (SCB) and activated carbon (AC) derived from palm kernel for the removal of Cd (II) under different experimental conditions. Batch experiments were carried out at various pH (3-12), adsorbent dosage (0.01-2 g) and contact time (15-150 min). The maximum Cd (II) removal was shown by SPW (90%) followed by SCB (55%) and AC (30%) at pH 7 with a contact time of 120 min, adsorbent dosage of 1.0 g and at 1.0 ppm of the initial concentration of Cd (II) solution. The kinetics study shows that the adsorption process fitted the pseudo-second-order-model. The experimental data was analysed by both Freundlich and Langmuir isotherm models. It was found that the Langmuir model appears to well fit the isotherm. The Langmuir maximum adsorption capacity calculated from Langmuir for SPW, SBC and AC were 0.3332 mg/g, 0.1865 mg/g and 0.1576 mg/g respectively. The order of Cd (II) removal by the adsorbents was SPW>SCB>AC. Thus, SPW may be an alternative adsorbent for the removal of Cd (II) ions form aqueous solution. The characterization of the SPW, SCB and AC were also carried out by using Scanning Electron Microscopy (SEM) and Nitrogen Gas Adsorption Single Point Surface Area Analyzer (BET).

Abstract: The polymer matrix of poly (metyl methacrylate) (PMMA) has been introduced with the titanium dioxide (TiO₂) nanopowder to study the effects of the TiO₂ size on the properties of the nanocomposites. The particle size is playing an important role in determining the properties of the nanocomposite. The decrease the filler size has increase the thermal decomposition of the nanocomposites due to the higher amount of the filler between the polymer chains. The results of X-ray diffraction (XRD) and Energy Dispersive X-Ray Spectrometry (EDS) also were discussed in this paper.

Abstract: Electron field emission properties of multi-walled carbon nanotubes (MWCNTs)/polyethylene oxide (PEO) thin films composites with (5%, 15%, 25%, 33%, 40% and 50 % loading of MWCNTs) were investigated. JE curved were measured and modeled according to FowlerNordheim theory. Sample with 33% MWCNTs loading showed the best results with the turn on and threshold fields of 7.66 V/μm and 9.72 V/μm respectively. With 15% MWCNTs loading, the highest enhancement factor of 1509 was observed. Excellent current stability, for the duration of about 34 min was observed for all samples. Raman spectroscopy analysis showed a good matrix/filler interaction and thermogravimetric analysis indicated that thermal degradation of the composites occurred in two stages.

Abstract: Cadmium Selenide (CdSe) was obtained by using spray-deposited method which is using the sodium selenosulfite as Se precursor and cadmium chloride (CdCI) as cadmium (Cd) precursor. Time for each spray-deposited was used as the main parameter to investigate the properties of CdSe nanoparticles. By using FESEM for surface morphology and X-ray Diffraction (XRD) studies reveal that the CdSe nanoparticles with cubic crystal structures. In this research, the effect of time of spray deposited was main parameter to know the CdSe properties. The set of time was set from 10 min until 50 min. From FESEM result the size of CdSe nanoparticles were in the range 60-70 nm and the crystalline was hexagonal from XRD result. By using Scherrer equation, the size of crystalline of CdSe nanoparticles was determined from XRD characterization, the size was 60-70 nm. The size of CdSe nanoparticles from FESEM images were 60-80nm.

Abstract: This paper discusses the improvement of properties of ENR/Si composites by using concentrated ENR without using any chemical modification on the silica or latex. The composite showed a stronger reinforcing ability without addition of coupling agents. The ENR matrix reinforced the rubber by increasing the compatibility between rubber matrix and silica. Scanning electron microscopy and atomic force microscopy were performed to study the composites topology. The importance of this study is to prepare masterbatch containing ENR reinforced with Si for tyre processing industry. This masterbatch can be use directly for tyre processing compared to the conventional method.

Abstract: Nanostructured zinc oxide (ZnO) thin films can be obtained by spin coating deposition technique. In this work, the effects of aluminum (Al) doping on the nanostructured ZnO films were investigated. The structural changes of ZnO films doped with Al ranging from 1 to 6 at.% were observed using a field emission scanning electron microscope (FESEM) and an x-ray diffractometer (XRD). The conductivity changes were obtained using a current-voltage (I-V) measurement system. In order to tailor the optical properties of Al-doped ZnO film for optoelectronic applications, its transparency and band gap were obtained using an ultra violet visible (UV-Vis) spectroscopy. The details explanation on the mechanism of ZnO structural and conductivity changes will be discussed detail in this paper.

Abstract: ZnO thin film was successfully deposited on different substrate by sol-gel spin coating. Zinc acetate dihydrates, diethanolamine and isopropyl were used as starting material, stabilizer and solvent respectively. Two different substrate used in this work are p-type silicon wafer and porous silicon. Porous silicon was prepared by electrochemical etching. In order to study the surface morphology, field emission scanning electron microscopy (FESEM) was employed. It is found that, ZnO thin film was composed by ZnO nanoparticles. The averages size ZnO nanoparticle is 23.5 nm on silicon and 17.76 nm on porous silicon. Based on Atomic Force Microscopy (AFM) topology analysis, surface of ZnO thin films on porous silicon was rougher compared to ZnO thin films on silicon due to substrate surface effect. Photoluminescence spectra shows two peaks are appear for ZnO thin film on silicon and three peaks are appear for ZnO thin film on porous silicon. PL spectra peaks of ZnO thin film on silicon are correspond to ZnO and ZnO native defects while peaks of PL spectra on porous silicon are corresponds to ZnO, ZnO native defects and porous silicon.