Continuous Synthesis of Surface-modified Zinc Oxide Nanoparticles using Supercritical Methanol

摘要

Surface-modified zinc oxide (ZnO) with diameters of 400 nm were synthesized rapidly and continuously in supercritical methanol at temperature 400°C and at pressure 30 MPa by using a flow type reactor system and decanoic acid (C_9H_(19)COOH) as an organic modifier. Transmission electron microscopy (TEM) showed that the usage of supercritical methanol and the addition of decanoic acid changed the shape and size of the nanoparticles. Wide angle X-ray diffraction (WAXD) analysis revealed that the surface-modified nanoparticles had ZnO crystalline structure. Dispersion test in solvents including water, ethylene glycol and transformer oil showed that the addition of organic modifier into the reaction system significantly affected the dispersion stability of nanocrystals. The results of Fourier transform infrared (FT-IR) demonstrated that reagents comprised of aliphatic groups associated with decanoic acid and hydroxyl group chemically bounded onto the surface of ZnO nanoparticles.