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by
A. Kassim |
Total Records (
3 ) for
A. Kassim |
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M.Y. Lim
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W. Mahmood Mat Yunus
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A. Kassim
and
H.N.M.E. Mahmud
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The thermal diffusivity has been measured for the Polypyrrole-Polyethylene Glycol (PPy-PEG) composite films by the open photoacoustic method. The experimental data were analyzed for thermal diffusivity by fitting procedure. The different process parameters such as different concentrations of insulating polymer, monomer and electrolyte and the different voltages used to prepare the PPy-PEG composite films brought changes in thermal diffusivity. The process condition of 0.20 M pyrrole, 0.10 M p-toluene sulfonate and 1×10-3 M PEG at 1.20 volt (vs SCE) appeared as the optimum condition and the PPy-PEG composite film produced from this optimum condition shows the highest thermal diffusivity (7.88×10-7 m2 s-1). |
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Z.A. Talib
,
Z. Baba
,
S. Kurosawa
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H.A.A. Sidek
,
A. Kassim
and
W.M.M. Yunus
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A device was constructed to monitor viscosity of solutions using fundamental frequency of 9 MHz and 10 MHz quartz crystal. Piezoelectric quartz crystals with gold electrodes were mounted by O-ring in between liquid flow cell. Only one side of the crystal was exposed to the solutions which were pumped through silicon tube by a peristaltic pump. The measured frequency shift was observed in order to investigate the interfacial behavior of some selected solution in contact with one surface of Quartz Crystal Microbalance (QCM). An analysis of the interaction between an AT-cut quartz crystal microbalance and various liquid system of analytical interest is presented. The analysis which includes piezoelectric effects and other influences; liquid properties, experimental conditions and the characteristic of the solution are reported. Oscillation in distilled water is taken as a reference. The frequency change caused by the density (ρ, gcmˉ3) and viscosity (η, gcmˉ1sˉ1) were found to be proportional to the square root of the product, (ρ η). The result suggested that analysis of small frequency shifts during EQCM studies needs to account for changes in ρ and η of the solution. Generally, all the liquid tested showed an increment of the frequency shift with increasing content of solutes. For each solution, the frequency was recorded as the concentration increases from distilled water to a very concentrated solution. The frequency measurements carried out for saccharide solution produces the maximum changes of frequency shift compared with other solutions. |
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M. Y. Lim
,
W. M.M. Yunus
,
Z. A. Talib
,
A. Kassim
,
C. F. Dee
and
A. Ismail
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Problem statement: The aim of this research was to study the electrical and optical properties of N, N`-bis(Inaphthyl)-N,N`-diphenyl-1,1`-biphenyl-4,4`-diamine (NPB) organic materials often used as hole transport layer in Organic Light-Emitting Devices (OLED). Approach: The NPB layer was prepared using the thermal evaporation method. From photoluminescence spectra, two peaks at 630 and 480 nm were observed with 55 nm NPB. The electrical conductivity was strongly influenced by the layer thickness. Results: The energy band gap of each NPB layer was successfully presented in the range of 2.4-2.9 eV. Conclusion: This study successfully showed the effect of different thickness of NPB in OLED. |
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