Materials Science Forum Vol. 1025

Abstract: Metalloporphyrin-based nanostructures were fabricated on 3-aminopropylmethoxysilane-modified indium tin oxide (ITO) surface. UV-visible spectroscopy and cyclic voltammetry are used for investigating electronic absorption spectra and catalytic activity in oxygen reduction reactions as alternative cathode electrochemical catalysts for polymer electrolyte membrane fuel cells (PEMFCs). Using of 5,10,15,20-tetrakis-(4-amiophenyl)-porphyrin-Co (II) as a building block and 1,4-phenylene diisocyanate as a linker, the mixed toluene/chloroform solution-based layer-by-layer process can produce linear growth of 5,10,15,20-tetrakis-(4-amiophenyl)-porphyrin-Co (II) up to 30 layers through urea bonds. The vacuum thermal annealing process demonstrated the improvement of catalytic activity in oxygen reduction reaction.

Abstract: This paper presents the thermophysical properties of zinc oxide nanofluid that have been measured for experimental investigation. The main contribution of this study is to define the heat transfer characteristics of nanofluids. The measuring of these properties was carried out within a range of temperatures from 25 °C to 45 °C, volume fraction from 1 to 2 %, and the average nanoparticle diameter size is 25 nm, and the base fluid is water. The thermophysical properties, including viscosity and thermal conductivity, were measured by using Brookfield rotational Viscometer and Thermal Properties Analyzer, respectively. The result indicates that the thermophysical properties of zinc oxide nanofluid increasing with nanoparticle volume fraction increasing, as well as the thermophysical properties of zinc oxide nanofluid affected by the change in temperature.

Abstract: This work focuses on the electrical properties study of solid biopolymer electrolyte (SBE) based plasticized carboxy methylcellulose (CMC) doped dodecyltrimethyl ammonium bromide (DTAB). Different weight percentage of ethylene carbonate (EC) which acts as plasticizer was incorporated into SBE system and were successfully prepared via solution casting technique. The conduction properties of SBE was investigated by using electrical impedance spectroscopy (EIS). The incorporation of 10 wt.% EC was found to achieve the highest ionic conductivity with 1.00 10^-3 S cm^-1 at room temperature. All SBE samples shows the ionic conductivity increased proportionally with temperature thus obeys to Arrhenius behaviour with regression value almost close to unity (R²~1). The electrical conduction behaviour of the CMC-DTAB-EC SBE reveals non-Debye behaviour without single relaxation properties.

Abstract: This study aims to investigate the feasibility of modifying graphite electrode with zero-valent iron (ZVI) to electrochemically detect the presence of 3-MCPD using two (2) deposition methods, namely dip coating and drop casting. Both methods were tested against in situ and ex situ ZVI formation method. Results showed that ex situ ZVI formation using drop casting method onto graphite electrode showed highest peak current when tested using cyclic voltammetry (CV). Results also showed that the 3-MCPD presence was detected at potential range of-25 mV to 45 mV due to the sudden spike in electrical current when tested using CV mode. The impact of this study is to provide a basis for further investigation of 3-MCPD detection in palm oil using electrochemical method due to its simplicity for the development of a portable, fast and reliable 3-MCPD sensor.

Abstract: The present work highlights on the structural and conduction properties of the solid biopolymer electrolytes (SBPE) based carboxymethyl cellulose (CMC) doped dodecyltrimethyl ammonium bromide (DTAB) and plasticized with ethylene carbonate (EC). The SBPE exhibits high ionic conductivity at room temperature where the highest value reaching 1.0 x 10^-3 S cm^-1 for sample containing with 10 wt. % of EC and increases the ionic conductivity when temperature was increased. Complexation within the SBPE has been confirmed by the FTIR analysis where the intermolecular interaction has improvised the coordination between CMC-DTAB and EC resulting in better structural and conductivity ability. The findings suggest that the great potential of CMC and make it promising to serve as an electrolyte for electrochemical devices.

Abstract: Metal organic framework (MOFs) of ternary metal precursors with different organic linkers are synthesized and fabricated on Ni-foam as the electrodes via hydrothermal reaction aiming to enhance the electrical conductivity and the specific capacitance, C_s. We report the preparation of ternary metal with different organic linkers named CoCuNi-bi using terephthalic acid (H₂bdc), CoCuNi-tri using trimellitic acid and CoCuNi-tetra using pyromellitic acid with increasing of active sites on Ni-foam substrate respectively. The CoCuNi-tetra demonstrates the highest C_s of 740 F g^-1 at 2 mV/s & 791 F g^-1 (87.9 mAh g­­­^-1) at 1 Ag^-1 respectively followed by CoCuNi-tri (674 F g^-1 at 1 A g^-1; 74.9 mAh g^-1) and CoCuNi-bi (591 F g^-1 at 1 A g^-1; 65.7 mAh g^-1). CoCuNi-tetra shows the best electrochemical performance hence it could be the encouraging electrode for supercapacitor materials.

Abstract: Bio-Dye is a dye derived from natural ingredients that have an important role in DSSC performance. This Bio-Dye is later in charge of absorbing sunlight entering the DSSC cells. Bio-Dye is a dye derived from natural ingredients that have an important role in the performance of the DSSC. This Bio-Dye is the one that will be in charge of absorbing sunlight entering the DSSC cells). One important key to know DSSC performance is to pay attention to the quality of the BIO-Dye. A good BIO-Dye can be seen by knowing the absorbance pattern and the function group of the dye its self. This research was conducted to determine absorbance patterns and functional groups based on pH variations in the wet and dry extraction methods contained in the Ocimum sanctum. The absorbance pattern was seen using a UV-Vis spectrophotometer and a functional group using FTIR. The chlorophyll pigment contained in the BIO-Dye (Ocimum sanctum leaf) was extracted using an ethanol solvent and added acetic acid to produce variations in pH values. The UV-Vis spectrometer measurement results showed the highest absorbance pattern was possessed by Ocimum sanctum dye in the dry extraction method and at natural pH (pH = 6.5). The peak absorbance they have is 648 nm, 614 nm, and 537 nm. The FTIR spectrum was obtained from Ocimum sanctum information containing the same functional groups when variations in pH values ​​were carried out in the wet and dry extraction methods. The functional groups are OH groups at wave number 3356.57 cm^-1, CH at 2975.37 cm^-1, C = O at 1652.50 cm^-1, CN at 1383.81 cm^-1, C = C at 880.25 cm^-1, and CH absorbed at wave number 1087.78 cm^-1. In general, it can be concluded that natural dye from Ocimum sanctum has a high absorbance in the visible light region and contains COOH compounds that can strengthen the bond of dye with TiO₂ semiconductors so that Ocimum sanctum can be used as a dye in Dye-Sensitized Solar Cells (DSSC).

Abstract: 3D printing allows industries to scale the development from rapid prototyping to mass production in an easier manner. However, a typical photopolymers resin for stereolithography 3D printing possesses lower mechanical properties which incapable to meet certain industrial requirements for high impact applications. Hence, 0.1 to 2.0 wt.% of graphene nanoplatelets (GnP) were incorporated into photo-curable polyurethane (PU) based resin through digital light processing (DLP) 3D printing to evaluate its reinforcement effect. FTIR spectrum proves that significant characteristics of PU were still dominant upon the addition of GnP, indicating there was no chemical interaction between PU and GnP. The interfacial adhesion and the homogeneity of GnP in PU matrix were investigated through morphological analysis and the strength and stiffness of the 3D-printed composites. Results shows, tensile strength and Young’s Modulus of the PU/1%GnP composite had an increment of 21% and 24%, respectively when compared to neat PU resin. However, further increment of GnP reduced the mechanical properties because of interruption in UV curing during printing, hence leading to interfacial voids and defects on the printed specimens.

Abstract: The use of steel in aerospace manufacture continues to decrease, owing in part to the sustainability and mechanical properties of fibers which have higher strength in minimum weight than steel. This study was defined to evaluate the mechanical properties of high-performance fibers, especially aramid, in terms of composite to be part of aircraft' wings called CN-235. The reinforcements were pre-impregnated by the materials manufacturers, under heat and pressure, with a pre-catalysed resin. Then the layering of aramid prepregs was carried with a dry lay-up process and cured in the autoclave at a temperature of 125°C and pressure of 3 bar for 90 minutes. The aramid composite was cured in various grain directions and examined in mechanical tests such as tensile, compression, and interlaminar shear strength tests. The result showed an insignificant difference between 0 and 90 degrees of grain direction in aramid composite in any properties. The strength of aramid composite with 90 degrees of grain direction has a higher value in the compression test (less than 5%) while having lower value in tensile and interlaminar shear tests.