Papers by Author: R. Puteh

Abstract: Measurement of the ionic conductivity for the CA-NH4CF3SO3-DMC system was carried out at frequencies of 50 Hz to1 MHz and also at temperatures of 298 K to 313 K. The plot of log σ versus 1000/T shows a linear behavior suggesting that the samples obey the Arrhenius relationship. The electrical relaxation of the system was analyzed using the complex electric modulus M* of the sample with the highest ionic conductivity at various temperatures. The analysis of electrical modulus and dissipation factor (tan δ) shows that charge transport occurs through a hopping mechanism.

Abstract: The corrosion protection property of the coating consisting of acrylic resin mixed with curcumin and dammar was investigated by immersing in 3% NaCl solution using potential - time measurement. The investigation was performed until corrosion occurred at the coating and substrate interface. As the coating degraded the penetration of electrolyte, the potential value of the coated sample decreases to a value of – 0.65 V. In this study the coating with pigment volume concentration of KC30% can withstand against corrosion by 3% NaCl solution.

Abstract: In this work, lawsonia pigment obtained from Henna leaves was mixed with acrylic resin and a mixture of acrylic and dammar resins (RD50%) to form two paint systems BC30% and BDP30%. The two paint systems were characterized by potential-time measurements, impact resistance, glass transition temperature (Tg) and cross hatch tests.

Abstract: Silicone modified acrylic polymer dispersion was prepared by blending methoxy functional silicone intermediate resin with acrylic polyol resin in different ratios. The physical, mechanical and thermal properties were investigated. The physical property of the blend has been carried out by using Kruss G40 contact angle measuring system, mechanical property of the blend evaluated by using impact resistance tester and adhesion tester (Cross Hatch- Cutter) and thermal analysis has been carried out by using Metler Toledo thermal analysis system DSC821. It is found that the incorporation of 50% silicone resin with 50% acrylic resin gives good adhesion on metal substrate (mild steel substrate) and optimal cross-linking is achieved.

Abstract: Films of chitosan polymer doped with lithium acetate dihydrate (LiOAc.2H2O) and placticized with oleic acid (OA) and palmitic acid (PA) were prepared by the solution cast technique. The film containing 40.0 wt. % LiOAc and 10.0 wt. % of OA exhibit a room temperature conductivity of ~ 10-5 S cm-1 and the film containing 41.0 wt. % LiOAc and 7.7 wt. % of PA has conductivity ~ 10-6 S cm-1. The plot of ln(sT) versus 103/T for the highest conducting samples obey an Arrhenian relationship in the temperature range between 300 and 363 K implying that the conductivity is thermally assisted. FTIR spectroscopy and XRD techniques have been used for the complexation studies. The LiNiCoO2/chitosan-LiOAc-OA/MCMB electrochemical cell could be charged to a voltage of 4.2 V.

Abstract: The objective of this paper is to show that annealing lithiated transition metal oxide (LTMO) precursors obtained by the sol-gel method at insufficiently high temperatures may not produce the intended pure cathode active materials required in lithium batteries. In this work, LiMn1.5Ni0.5O4 which is a potential cathode active material in the 5 V-class is prepared by the solgel method. The precursor material was obtained when the solid gel was dried and heated at different temperatures in the range between 200 °C and 900 °C for 4 hours. It was observed that on heating the precursor material at least at 500 °C for 4 hours the material produced was LiMn1.5Ni0.5O4 in the present form as proven by the x-ray diffractogram (XRD). On heating at temperatures below this, the formation of LiMn1.5Ni0.5O4 was uncomplete and at temperatures above 500 °C the intensity of the peak at 2q = 18° decreases. The noise level also increased at temperatures above 500 °C.