Surfactant And The Preparation Of Nanomaterials

Nano-materials have attracted considerable attention due to their unique properties and superior application prospects. Surfactant is widely used in the preparation of nano-materials, such as, surface-modification for nano-materials, control on the size and morphology of nano-materials. In this dissertation, the different organic acid modified nanosized BaSO₄ were synthesized by a simple method in ethanol-water reaction system. The lanthanide orthophosphate with different morphologies were prepared by microemulsion method, microemulsion/hydrothermal method and microemulsion/ultrasonic method. The main results are summarized as follows.1. We prepared nanosized BaSO₄ particles modified with tetradecanoic acid, hexadecanoic acid and stearic acid in ethanol-water reaction system. The nanoparticles were characterized by Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), transmission electron microscope (TEM), dynamic light scattering (DLS) and thermo gravimetric analysis (TGA), respectively. The results indicated that the BaSO₄ modified with different organic acid having good dispersion in the presence of a certain concentration NH₃·H₂O and organic acid, the average diameters of barium sulfate were about 25nm, 20nm and 16nm obtained in the reaction system containing tetradecanoic acid, hexadecanoic acid and stearic acid, respectively and the crystalline states of BaSO₄ were all orthorhombic.2. The lanthanide orthophosphates with different morphologies, such as spherical, radicalized needle-like praseodymium orthophosphate (PrPO₄), spherical erbium orthophosphate (ErPO₄), were prepared in microemulsion solutions formed by p-octyle polyethylene glycol phenylether (OP), n-pentanol (C₅H₁₁OH), cyclohexane (C₆H₁₁) and water, through varying the ω₀ (molar ratio of water to surfactant), aging time and the additional method of reactants. The fibre-net-like PrPO₄ and prickly sphere-like ErPO₄ were synthesized in the microemulsion solution formed by cetyltrimethylammonium bromide (CTAB). n-butanol (C₄H₉OH), n-heptane (C₇H₁₆),...