10 research outputs found

    SYNTHESIS AND CHARACTERIZATION OF CdS IN DIOL VANILIN LIQUID CRYSTAL MONOMER

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    Nanocomposites comprising diol-vanilin and cadmium sulfide (CdS) has been synthesized via chemical precipitation method in ethanol at refluxed temperature (160 oC) for 12 hours. CdCl2. 2.5H2O and thiourea as cadmium and sulfide precursors respectively were employed. Diol vanilin is a thermotropic liquid crystal monomer which exhibits enantiotropic nematic metaphase texture when observed under polarizing microscope and confirmed by DSC thermal stability study. A series of different mass composition  of diol vanilin and CdS nanocomposites ranging from  0.1:1.0 till 1.0:1.0(w/w) were prepared and characterized using XRD, TEM, SEM-EDX, POM and DSC. The X-ray diffraction pattern (XRD) showed broad peaks due to the formation of cubic CdS nanoparticles in diol vanilin matrix. The nanocomposites at low mass composition  of CdS still maintained their nematic phase. However, the liquid crystal property was affected when the mass  composition  of CdS in nanocomposite was increased and the liquid crystal characteristic vanished when the mass composition  was at 0.6:1.0. .    Keywords: CdS, diol vanilin, thermotropic liquid crystal, nanocomposite

    Synthesis and characterization of a new heterocyclic azo pigment

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    A new heterocyclic coupling agent has been produced from the reaction of maleic anhydride and p-aminophenol, namely N-(4-hydroxylpheneyl)maleimide. The coupling agent underwent azo coupling reaction with aromatic amine, which is p-aminophenol to produce a new heterocyclic azo pigment. The pigment was then subjected to solubility, hiding power and light fastness test. Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet/Visible (UV/Vis) Spectroscopy, and Nuclear Magnetic Resonance Spectroscopy (1H-NMR, 13C-NMR) were used to obtain the characteristics and structural features of the pigment

    SYNTHESIS AND CHARACTERIZATION OF CdS IN DIOL VANILIN LIQUID CRYSTAL MONOMER

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    Nanocomposites comprising diol-vanilin and cadmium sulfide (CdS) has been synthesized via chemical precipitation method in ethanol at refluxed temperature (160 oC) for 12 hours. CdCl2. 2.5H2O and thiourea as cadmium and sulfide precursors respectively were employed. Diol vanilin is a thermotropic liquid crystal monomer which exhibits enantiotropic nematic metaphase texture when observed under polarizing microscope and confirmed by DSC thermal stability study. A series of different mass composition of diol vanilin and CdS nanocomposites ranging from 0.1:1.0 till 1.0:1.0(w/w) were prepared and characterized using XRD, TEM, SEM-EDX, POM and DSC. The X-ray diffraction pattern (XRD) showed broad peaks due to the formation of cubic CdS nanoparticles in diol vanilin matrix. The nanocomposites at low mass composition of CdS still maintained their nematic phase. However, the liquid crystal property was affected when the mass composition of CdS in nanocomposite was increased and the liquid crystal characteristic vanished when the mass composition was at 0.6:1.0.</p

    Synthesis of PANI/hematite/PB hybrid nanocomposites and fabrication as screen printed paper based sensors for cholesterol detection

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    In this work, the composites of polyaniline/nano-hematite (α-Fe2O3)/Prussian Blue (PB) were successfully synthesized via a sonochemical method. This nanocomposite (PB/CPANI) has been used for the modification of paper-based sensors for cholesterol detection. The electrochemical studies of this nanocomposite showed a well-defined cyclic voltammogram for hydrogen peroxide (H2O2) with a remarkable electrochemical sensitivity. This nanocomposite modified paper-based electrode also showed excellent electrocatalytic activity towards H2O2 in the interference-free cathodic region. In addition, cholesterol oxidase was immobilized on the PB/CPANI-modified paper-based electrode for selective detection of cholesterol. Under optimum conditions, a linear range of 0.6–6.0 mM with a very low detection limit of 0.52 mM for cholesterol and a good sensitivity of 411.7 μA mM−1 cm−2 were obtained which indicated that the method presented is outstandingly appropriate to determine cholesterol in bovine serum albumin. This work might be an alternative, interference-free, and cost-effective approach for biomonitoring of cholesterol both in methodological studies and in clinical laboratories

    Pahangine A and B, two new oxetane containing neolignans from the barks of Beilschmiedia glabra Kosterm (Lauraceae)

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    Phytochemical investigation on the barks of Beilschmiedia glabra Kosterm led to the isolation of two new oxetane containing neolignans, Pahangine A (1) and Pahangine B (2) together with eight known compounds. The structures of isolated compounds were elucidated by extensive spectroscopic analysis including 1D and 2D NMR (1H–1H COSY, HSQC, and HMBC), DEPT-Q NMR, and by comparing with the published data. A possible biosynthetic pathway for the formation of 1 and 2 was proposed
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