Synthesis Of Silica Microspheres And Nanocomposites And Study Their Lead Ions Adsorption Property

Silicates are low cost, stable, and safe materials. They are widely used in carriers,catalysts, bionano-composites, adsorption. In particular, nano silicate materials have beenused as adsorbents for years due to their large specific surface area. Examples of silicateswith different morphologies including nanotubes, nanowires, core–shell, hollow spheres andinorganic composite structure have been reported. Hollow spheres materials are known fortheir high surface areas and favorable mesopores as well as abundant functional groupsmight be ideal adsorbents to remove heavy metal in water.In this study, a simple method was used to synthesis polystyrene and silica compositenanospheres. Under different preparation conditions, Heavy metal adsorbent were fabricatedby different methods, such as assemble and inorganic modification. Transmission electronmicroscope(TEM), scanning electron microscopy(SEM) were employed to characterize theas-synthesized samples. The Specific research contents are as follows:(1)The SiO2-coated PS(PS@SiO2) particles of230nm in diameter were prepared byusing TEOS as the precursor, PVP functionalized polystyrene (PS) as the templates. Afterremoving PS templets by calcination and solvent extraction, two kinds of hollow silicananospheres (HSN-1and HSN-2) were fabricated. The ability of these nanospheres toremove the heavy metal ions lead from solution was tested. The nanospheres by dissolutionshow the best ability to remove the heavy metal ions. All the silica spheres were tested toremove the heavy metal ions. The exhibited maximum adsorption capabilities can reach56mg·g-1.(2)The PS@SiO2as self-assembly nanospheres, Synthesis a kind of silica spheres inthe oil-water system. Changed the time of self-assembly(6h,8h,12h,24h). The resultsdemonstrated that: The best time to self-assembly is12h at least as the spherical is perfect.After removing PS templets by calcination and solvent extraction, multilevel structure ofsilica spheres were fabricated. All the silica spheres were tested to remove the heavy metalions. The silica spheres of maximum adsorption capabilities can reach64mg·g-1. (3)SiO2-coated PS(PS@SiO2) particles hydrolyze with different amount of (n(TEOS):n(Ni)=4:1,6:1,8:1,10:1) of nickel acetate using sol-gel method. The results demonstratedthat: PS@SiO2particles doped with nickel with n(TEOS): n(Ni)=8:1exhibited the highestability to remove the heavy metal ions, but adding of nickel lowered the ability. Afterremoving PS templets by calcination and solvent extraction, two kinds of Ni/Si compositematerial were created. All Ni/SiO2composite material were tested to remove the heavymetal ions. The maximum adsorption capabilities of Ni/Si composite material by was21mg/g.