Study on preparation and super-hydrophobicity of PbWO_4 nanocrystals modified by oleic acid

Using oleic acid as surface modifying agents,the PbWO4 nanocrystals coated with oleic acid were synthesized by hydrothermal method.The effects of amounts of oleic acid on the modification of nano-PbWO4 particles were also discussed.The as-prepared PbWO4 particles were characterized systematically by means of X-ray diffraction(XRD),scanning electron microscope(SEM),Fourier transform infrared spectroscopy(FT-IR) and contact angle analyzer.It was found that the optimum amount of oleic acid was 6%;the XRD patterns indicate that the well-crystallized PbWO4 nanocrystals can be obtained by using the given synthetic parameters,and the average diameter were about 32nm.The results revealed that the —COOH group of oleic acid had chemically reacted with the surface of PbWO4 nanocrystals via surface modification by FT-IR;the oleic acid modified PbWO4 nanocrystals had good dispersion and not reunited.Furthermore,the contact angle between the modified PbWO4 and water amounted to 153.08°,which showed that the modified PbWO4 owned super hydrophobic surfaces.And it had good dispersion and stability in organic solvents.