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Idris R.,University Technology of MARA | Bujang N.H.,Advanced Material Research Center
Advanced Materials Research | Year: 2014

Epoxidized Natural Rubber (ENR50), lithium imide salt, [LiN(SO2CF3)2] with and without solvent were prepared by solvent casting technique. Non solvated polymer electrolyte showed modest ionic conductivity at ambient temperature. To further enhance ionic conductivity a mixed solvent of ethylene carbonate/propylene carbonate was added into the system. Thermal characterization showed that single transition glass temperature (Tg) for all systems and amorphous phase is dominant. DSC traces of non-solvated samples have shown Tg values increased whereas addition of mixed EC/PC solvent into the electrolyte system reduced their values respectively. Impedance measurements for the solvated epoxidized natural rubber (ENR) based electrolyte systems have shown optimal ionic conductivity 10-4 S cm-1 whereas 10-6 S cm-1 for a non-solvated one. ENR electrolyte systems showed similar temperature dependence, which suggests that the conductivity is thermally activated. © (2014) Trans Tech Publications, Switzerland. Source

Farhana N.I.E.,University Malaysia Perlis | Abdul Majid M.S.,University Malaysia Perlis | Paulraj M.P.,University Malaysia Perlis | Ahmadhilmi E.,Advanced Material Research Center | And 2 more authors.
Composite Structures | Year: 2016

This study proposes a novel approach to determine the fibre volume fraction in composites using vibration based non-destructive technique with a neural network. Currently, the volume fraction of a glass fibre/matrix based composite material is assessed using destructive techniques. Instead of changing or destroying the structure, a new non-destructive approach based on vibration analysis is proposed. Complete experimental protocols were developed to capture the vibration pattern. An auto-regressive model was developed as a feature extraction tool to classify the fibre volume fractions and as a pole tracking algorithm. The classification performances were within the range of 90-98%. For NDT method to be efficient, the classification results were then compared with destructive burn-out technique. The results of non-destructive test showed good agreement with those obtained through destructive test suggesting that the proposed method is an alternative to ASTM D2584-11 for determining the volume fraction of a glass fibre/matrix composite. © 2016 Elsevier Ltd. Source

Haameem J.A. M.,University Malaysia Perlis | Abdul Majid M.S.,University Malaysia Perlis | Afendi M.,University Malaysia Perlis | Marzuki H.F.A.,Advanced Material Research Center | And 2 more authors.
Composite Structures | Year: 2016

The mechanical properties of Napier grass fibre-reinforced composites were characterised. Napier grass fibres were extracted through water retting process. The effect of alkali-treatment on the tensile properties and morphology of the fibres was investigated. The fibres were alkali-treated using NaOH solutions of various concentrations and subjected to single fibre testing. The morphology of the fibres was observed using scanning electron microscopy. The 10% alkali-treated Napier grass fibres yielded the highest strength. To fabricate the polymer composites, Napier grass fibre and polyester resin were used as the reinforcing material and polymer matrix, respectively. The tensile and flexural properties of the composites were studied. In general, up to a certain threshold value, the tensile and flexural strengths of the composites increased as the fibre volume fractions increased, following which, there was a reduction in strength. The maximum tensile and flexural strengths of the composites were obtained at 25% fibre loading. © 2015 Elsevier Ltd. Source

Kim S.H.,Korea University | Son H.J.,Korea Electronic Technology Institute | Park S.H.,Korea University | Hahn J.S.,Advanced Material Research Center | Kim D.H.,Korea University
Solar Energy Materials and Solar Cells | Year: 2016

The stability of slot-die coated flexible organic photovoltaic (OPV) modules with inverted structures of indium tin oxide (ITO)/ZnO/photoactive layer/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/Ag was analyzed under damp heat conditions. The work primarily focused on the understanding of the degradation mechanism of organic photovoltaic modules in very severe operating conditions (85°C/85% relative humidity [rh]). The electrical change of the OPV module was measured as a function of the aging time under damp heat. A rapid drop in the efficiency of the module was observed, mainly caused by the decline of the open-circuit voltage (Voc) and fill factor (FF). We supposed that the degradation of the modules mainly progressed by the oxygen and moisture penetrating the terminals or at the edges of the barrier films. The physical modification of the layers composing the device by degradation was observed; hence, morphological and chemical analyses were conducted. The analyses revealed that Ag atoms migrated to the interlayers of the cell, resulting in the increase of shunt paths; this was the main reason underlying the reduction of Voc and FF of the OPV module under damp heat. The ZnO layer was also etched by the acidic molecules from the diffused PEDOT:PSS polymer. In addition, the performance parameters of several OPV modules were evaluated simultaneously under damp heat conditions for 1000 h. The same lifetime patterns were observed although the initial efficiencies of the modules were diverse. The interpretation of the lifetime patterns and a suggestion for an objective comparison between the modules showing different initial efficiencies were also addressed. © 2015 Elsevier B.V. All rights reserved. Source

Ibrahim S.M.,Hiroshima University | Ibrahim S.M.,Advanced Material Research Center | Xu R.,Changzhou University | Nagasawa H.,Hiroshima University | And 5 more authors.
RSC Advances | Year: 2014

A promising new triazine-based nitrogen-rich organosilica (TTESPT) membrane has been developed for molecular separation processes in gas (gas separation) and liquid phases (reverse osmosis (RO)). By adjusting the H2O/TTESPT molar ratio, we found a promising technique for tuning the pore network of TTESPT membranes. An increase in the H2O/TTESPT molar ratio from 60 to 240 fully hydrolyzed all the ethoxide groups in the TTESPT membrane, which reduced the size of the pores in the silica pore network. A TTESPT membrane with a high H2O/TTESPT molar ratio exhibited a high degree of selectivity for H2/SF6 (greater than 4000) at a permeation temperature of 200 °C. This membrane also demonstrated high sodium chloride (NaCl) rejection (>98.5%) with water permeability of >1 × 10 -12 m3 m-2 s-1 Pa-1 under operating conditions of 1 MPa and 60 °C during a RO experiment. As the operating temperature was increased from 25 to 60 °C, the NaCl rejection was constant without displaying the characteristic flux deterioration. This showed that the membrane retained a stable hybrid network structure. © 2014 the Partner Organisations. Source

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