Advanced Materials Research Vol. 795

Abstract: This paper presents a short review of research works on the development of sustainable cementitious matrix composites with addition of potential mineral wastes as sand replacement materials. The study emphasizes on the possibility of recycling and sustain the mineral wastes from natural and industrial by-products in order to reduce the consumption of natural resources, energy and cost, and at the same time to reduce the environmental pollution. The aim of this review is to share the ideas and present the findings from previous works undertaken to evaluate the suitability of mineral wastes as a sand replacement materials to produce sustainable and durable construction materials in the future.

Abstract: Many new sustainable porous materials were developed for gas adsorption applications. Common materials such as activated carbon, clay materials and metal organic framework (MOF) that utilized as potential porous adsorption materials were studied. The article was also discussed on the fabrication methods of porous materials. Adsorptions of flue gas using porous materials were reviewed. It was found that the adsorption properties of porous materials were highly dependent on surface area, selectivity and impregnation. Low cost porous adsorbents such as clay and fly ash were also reviewed as potential and cost effective materials to be used in industries.

Abstract: Porous metals that have open pores structure with low density and light weight properties are suitable to be used in many engineering applications. In this work, the porous aluminum was fabricated via sintering dissolution process (SDP). Aluminum and sodium chloride (20, 40, 50 wt. %) powders were mixed together to produce a homogeneous mixture. The mixture was compressed at 200 MPa followed by sintering at 500 °C, 550 °C and 600 °C for 2 hours. The sintered samples were placed under a warm running water stream for 45 min to dissolve the sodium chloride that embedded in the aluminum. From the result, the sodium chloride content controlled the total porosity between 20% and 40% of the sintered aluminum. Porosity increased and compressive strength decreased as the content of NaCl increased. It was also observed, the porosity increased with increasing sintering temperature for the sample with 40 wt. % of NaCl.

Abstract: Organic light-emitting diodes (OLEDs) were fabricated containing guest molecule of Tris (8-hydroxyquinoline) aluminum (Alq₃) blend with host molecules of N,N-diphenyl-N,N-bis (3-methylphenyl)-1,1-biphenyl-4,4-diamine (TPD) and 2-(4-biphenylyl)-5-phenyl-1,3,4-oxadiazole (PBD) small molecules. Optical, photoluminescence (PL) and electroluminescence (EL) properties were investigated with respect to blend systems. The obtained optical energy gap and PL intensity in the blend systems increased due to the transfer of high energy from the host to guest molecules. Luminance and current efficiency were enhanced for blended OLEDs as compared to that of pure Alq₃, related to high exiton recombination in guest caused by high injection and accumulation of charge carrier.

Abstract: This research work investigates the influence of the annealing process upon the performance of photo-emissive layer of organic light-emitting diode (OLED). The photo-emissive layer consists of a ternary blend of N, N-diphenyl-N,N-bis (3-methylphenyl)-(1,1-biphenyl)-4,4-diamine (TPD), 2-(4-biphenylyl)-5-phenyl-1,3,4-oxadiazole (PBD) and tris-8-hydroxyquinoline (Alq3), to produce TPD:PBD:Alq3 (at 1:1:1 ratio) blend thin films, in which the material solutions are deposited onto clean substrate via spin-coating method. The samples were annealed at 100°C in 10, 20 and 30 minute of time in an open-air condition. The results reveal that the annealing process at 10 minutes produces an optimum performance of the ternary OLED.

Abstract: Biodegradability of films made from sago starch blend with PVA and LLDPE has been investigated. Blend films with different starch concentration were buried in the soil for 30 days for degradation test. FTIR and SEM have been performed on the film before and after degradation test to evaluate the biodegradability of the films. It was found that degradation rate increases with addition of starch into the blends.

Abstract: The effects of physical and morphological properties of styrene butadiene rubber/virgin chloroprene rubber blends (SBR/CRv) and styrene butadiene rubber/recycled chloroprene rubber blends (SBR/CRr) were investigated. Both SBR/CRv blends and SBR/CRr blends were prepared using two roll mill at room temperature with blend ratios 95/5, 85/15, 75/25, 65/35 and 50/50. The range size of CRr used in this study was 0.3 0.7 mm. The SBR/CRr blends shows higher value of hardness and crosslink density compared to SBR/CRv blends at all blend ratios. The scanning electron microscopy (SEM) of tensile fracture surface of SBR/CRr blends at 15 blend ratio illustrated a better adhesion and dispersion of CRr with SBR matrix compared with SBR/CRv blends.

Abstract: This work investigates the dehydrogenation of TiH₂ powder during isothermal heating at 600°C using the static x-ray scans of high temperature x-ray diffraction (XRD). As-received TiH₂ powder with a particle size of 5 μm and purity of 99.1% was used for this measurement. With increasing temperature, phase transformations occurred because of dehydrogenation and it happened very fast. It was found that during the phase transformation of TiH₂ to titanium, some transitional phases observed and occurred. This finding confirmed the in-situ determination of TiH₂ powder dehydrogenation by using Rietveld Refinement Method from our previous research. This study is useful for the fabrication of titanium-based composites and titanium alloys from TiH₂ powder because the different phases in TiH₂ will affect the final mechanical properties in titanium.

Abstract: This research paper presents a study on the development of cement composites reinforced coconut fiber with fly ash addition. Various content of coconut fiber (3 wt. %, 6 wt. %, 9 wt. %, 12 wt. % and 15 wt. %) was added to the cement composites composition as reinforcement. Additions of 20 wt. % fly ash and 80 wt. % of sand were used as a mixture of cement matrix. Water to cement weight ratio ranging from 0.55 to 0.70 was used in the cement composites to maintain workability. The cement composites were then cured for 7, 14 and 28 days. The result is presented in terms of compressive strength, modulus of rupture and fracture behavior.

Abstract: The blends of thermoplastic polyurethane (TPU) with natural rubber (NR) at four different blend ratios were prepared via melt blending at 180°C and 190°C, with addition of liquid natural rubber (LNR) as compatibilizer. The effect of blend ratio and temperature swelling index was studied. The equilibrium swelling index of TPU and its blend increase with increasing of NR, because of the easiness for solvent to diffuse into the gap between rubber molecules. The temperatures of blending also give effect to swelling behavior. Swelling index of all samples was higher when mixed the blends at higher temperature.