Advanced Materials Research Vol. 795

Abstract: Nowadays, many researchers have been studying on the layered rock salt-type structure as cathode materials for the lithium ion batteries. LiCoO₂ is the most commonly used cathode material but Co is costly and toxic. Thus, alternative cathode materials which are cheaper, safer and having higher capacity are required. Replacing Co with Ni offered higher energy density battery but it raised interlayer mixing or cation disorder that impedes electrochemical properties of batteries. This paper has reviewed some recent research works that have been done to produce better and safer cathode materials from the structural perspective.

Abstract: A composite comprising cyclopentyl trisilanol silsesquioxanes (CpSSQ(OH)₃) and 50% epoxidized natural rubber (ENR-50) was prepared at reflux temperature employed hydrochloric acid (HCl) as catalyst. HCl was found to be an effective catalyst to promote ring opening reaction of ENR-50 and tailored CpSSQ(OH)₃ to the ENR-50 polymer chains via chemical reaction. FTIR spectroscopy reveals a hydroxyl stretching indicating the occurrence of epoxide ring opening reaction. ¹H NMR analysis further proved the incorporation of CpSSQ(OH)₃ into ENR-50 polymer chains via shiftment of proton chemical shift and addition in the proton integrals. Si ²⁹NMR analysis evidence the Si-O-C bond through a chemical shift of silanol group from CpSSQ(OH)₃.

Abstract: In this paper, the physical characteristics and memristive behavior of TiO₂ nanostructures grown at different substrate positioning by wet chemical solution were investigated. TiO₂ thin film as a seed layer for TiO₂ nanostructures growth was first deposited on ITO-coated substrate by RF magnetron sputtering method. TiO₂ nanostructures were then grown by immersing the TiO₂ thin film/ITO/glass sample in 10M NaOH solution at 80 °C while studying the effect of the substrate position to the nanostructure growth and thus its memristive behavior. Characterization on the growth morphology of TiO₂ nanostructures was observed using scanning electron microscopy (FESEM). The current-voltage (I-V) measurement of the device was investigated for its memristive behavior. Different growth morphology of TiO₂ nanostructures was observed at different substrate positioning. It was found that sample immersed with TiO₂ layer facing down the vessel result in the formation of TiO₂ nanowires and exhibit better memristive behavior.

Abstract: The pollution of water with heavy metals has been a great concern due to their toxic nature and adverse effect. Various techniques were employed to remove heavy metal namely physical, chemical, and biological treatment. Biosorption is one of the biological treatment that has emerged as a new technology for the removal and recovery of metal ions from aqueous solutions which is more environmental friendly. Biosorption using Tilapia fish scale was studied with the intention to remove zinc, plumbum, and ferum ions from synthetic wastewater. The optimum adsorption capacities of fish scale was investigated under several condition namely, pH, biosorbent dosage, initial heavy metals concentration, and contact time while final concentration was obtained by using Inductively Coupled Plasma-Mass (ICP-MS). The results revealed that 92.3% of zinc, 89.33% of plumbum, and 64.2% of ferum able to be sequestered under best adsorption conditions. The maximum percentage removals were observed at pH 6, 5.5, 4.5 and dosage 0.02 g, 0.001 g, 0.8 g at concentration 10 ppb, 0.3 ppb, 300 ppb for zinc, plumbum, and ferum ions, respectively. Maximum removal achieved at 3 hours contact time for ferum and zinc while 2 hours for plumbum. The results indicate that Tilapia fish scale is a promising method in removing ferum, zinc, and plumbum ions from aqueous solution.

Abstract: Cucumis melo rind was evaluated as a new biosorbent for the removal of Fe (II) and Mn (II) from synthetic groundwater solution. The maximum sorption capacity of Fe (II) and Mn (II) was found to be 4.98 mg/g and 1.37 mg/g respectively. Sorption was most efficient at pH 7 and 6.5 for Fe (II) and Mn (II) respectively. The biosorption of both metals increased as the quantity of biosorbent increased. The increase in initial metal concentration was associated with steep increase in biosorption at lower concentrations and progressively reaching towards plateau at higher metal concentration. FTIR demonstrated that hydroxyl and carboxyl groups were involved in the biosorption of the metal ions. The study points to the potential of new use of Cucumis melo rind as an effective sorbent for the removal of Fe (II) and Mn (II) from aqueous solution.

Abstract: Silicon carbide reinforced copper matrix (Cu-SiC_p) composites are highly rated as thermal management materials due to their high thermal conductivity and low thermal expansion properties. However, the Cu-SiC_p composites fabricated via the conventional powder metallurgy methods have substandard properties due to the weak bonding between the copper matrix and the SiC_p reinforcement. In order to strengthen the bonding, the SiC_p were coated with copper via electroless coating process. Based on the experimental results, a continuous copper deposition on the SiC_p was obtained. The Cu-Coated layer improved the green strength of the composites thus allowed a high volume fraction of SiC_p to be incorporated into the copper matrix. However, the increase in the volume fraction of SiC_p has a significant effect on the apparent porosity of the Cu-SiC_p composites. Nevertheless, the porosity of the Cu-Coated Cu-SiC_p composites remained significantly lower than those of non-Coated Cu-SiC_p composites especially at high volume fraction of SiC_p.

Abstract: This paper presents a simple and effective method to design chrome mask for microfludic fabrication. Microfluidic fabrication involves 9 major step and mainly depends on the master mold template formation by SU-8 photoresists using conventional photolithography process The chrome mask was design using AutoCAD software. Essentially, mask is a crucial element in a microfluidic fabrication in which resolution requirements and precise alignment are vital, each mask needs to be precisely aligned with original alignment mark. Otherwise, it cant successfully transfer the original pattern to the wafer surface causing microchannel formation failure. Thus, the initial design is compared with the fabricated chrome mask to achieved a better result during device fabrication.

Abstract: Polypropylene (PP) biocomposite containing 5, 10, 15, 20 and 25wt% of sodium hydroxide treated palm fruitlet fiber (TPFF) were prepared using Z-blade at 180°C at 50rpm. The composite was introduced with 3wt % of maleated anhydride grafted polypropylene (PP-g-MAH) as compatibilizer. The composites were characterized by performing tensile test and scanning electron microscopy (SEM) analysis. Results indicated that, the present of PP-g-MAH improved the tensile strength as the increasing of treated filler content. The improvement properties of the composite were attributed to better interfacial adhesion between the PFF and PP matrix in the presence of the PP-g-MAH. As for the overall results,5wt% TPFF/PP/PP-g-MAH composite shows the highest value tensile strength, 20wt% TPFF/PP/PP-g-MA composite exhibits the highest in Youngs modulus. While from the observation through SEM, the smooth surface fractured of 5wt% TPFF/PP/PP-g-MA which indicated as high rigidity compare to the other ratios.

Abstract: In this research, calcium carbonate (CaCO3) was compounded with rice husk/high density polyethylene (HDPE) and kenaf/HDPE composite at different filler loadings to produce hybrid composites. Melt flow index (MFI) and mechanical properties of hybrid composite was investigated. From the test results, the addition of CaCO3 filler had decreased melt flow index (MFI) on both composites. In terms of mechanical properties, tensile strength, elongation at break and impact strength decreased, whereas Youngs Modulus increased with the increase of CaCO3 in both kenaf/HDPE and rice husk/HDPE composites. Impact strength of unfilled rice husk/HDPE composite was lower than unfilled kenaf/HDPE composite, however impact strength of CaCO3/rice husk/HDPE hybrid composite were found to have slightly higher than CaCO3/kenaf/HDPE hybrid composite with addition of 10% and 20% of CaCO3.

Abstract: This paper deals with stress and failure characteristics of V-shaped epoxy adhesive joint. Effect of scarf angle upon failure morphology was investigated by tensile test and monitoring using high speed camera. V-shaped specimens were fabricated having bond thicknesses, t = 1.0 mm and various scarf angles (i.e. θ = 30 ̊, 45 ̊, 60 ̊, 75 ̊, and 90 ̊). From failure surface observation, failure morphology can be divided into 5 types consisting of interface failure and/or cohesive failure. Stress singularity plays a major role in failure morphology where higher singularity favors cohesive failure in the specimens tested.