SYNTHESIS AND CHARACTERIZATION OF CdS IN DIOL VANILIN LIQUID CRYSTAL MONOMER

H. L. Lee (Nanoscience Research Laboratory, School of Chemical Sciences, University Sains Malaysia, 11800 Penang, Malaysia)
M. Abu Bakar (Nanoscience Research Laboratory, School of Chemical Sciences, University Sains Malaysia, 11800 Penang, Malaysia)
J. Ismail (Nanoscience Research Laboratory, School of Chemical Sciences, University Sains Malaysia, 11800 Penang, Malaysia)
A.M. Issam (School of Industrial Technology, University Sains Malaysia, 11800 Penang, Malaysia)

Indonesian Journal of Chemistry
Vol 7, No 2 (2007)

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.