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Surface Modification Of Nano-silica With Amides And The Application Of Adsorption On Heavy Metal Ions

Posted on:2014-10-25Degree:MasterType:Thesis
Country:ChinaCandidate:J J SunFull Text:PDF
GTID:2251330425956622Subject:Biomedical engineering
Abstract/Summary:PDF Full Text Request
Nano silicon particles applied to the treatment of heavy metal ionpollution is attracting more and more attention. In this work, thePS-co-PVEA@SiO2microspheres and amino-modified mesoporoussilicon microspheres were successfully synthesized and the adsorptioncapacity of the heavy metals lead were discussed respectively. Theprimary coverage as follows:1. Grafting of amino containing polymer onto the surface of silicamicrospheres and their application as an effective sorbent for lead ions.(1) SiO2microspheres which have good dispersion effect anduniform sizes were synthesized by St ber method using tetraethoxysilaneas reactant, ammonia as a catalyst. The influence on the silica particlesize and morphology of the stirring velocity, the concentration oftetraethoxysilane(TEOS), the amount of ammonia added were studiedaccording to the factor analysis method. The optimal conditions werefinally determined as follows: the stirring velocity, the TEOSconcentration, the ammonia amount were900r/min,5.2M/L,8mLrespectively. The sample was characterized by XRD, SEM, TEM, FI-IRand nanoparticle sizer.(2) Synthesis of amino containing polymer grated onto the surface ofsilica microspheres (silica@polymer) and the application of adsorption onheavy metal ions. Monodispersed silica microspheres are synthesized bySt ber method and then activated by3-(methacryloxy)propyltrimethoxysilane (MPS). Amino containingpolymer was successfully grafted onto the surface via the seed dispersionpolymerization of styrene and N-(4-vinylbenzyl)-N,N-diethylamine in thepresence of divinylbenzene employing the3-(methacryloxy)propyltrimethoxysilane activated silica microspheres asthe seed. The polymerization led to thin polymer films coating silicamicrospheres (silica@polymer) and silica@polymer were about180nm.Fourier-transform infrared spectroscopy and energy dispersive X-rayspectrum demonstrate the existence of the amino group in the polymer film and the contents is almost equal to the feeding ratio. And thethickness of the polymer film prepared in this study was about30nm asdetermined by transmission electron microscopy. The synthesizedsilica@polymer was used as an effective sorbent for Lead ions (Pb2+).The adsorption properties, such as pH value effect, adsorption isotherm aswell as the adsorption kinetics, the effect of the silica@polymer sorbentamounts on the adsorption recovery and the reuse of the silica@polymersorbent were evaluated. The results demonstrated that the composite ofamino containing polymers and silica microspheres is efficient andreusable.2. Preparation of amino-modified mesoporous silicon microspheresand their application of adsorption on heavy metal ions. Mesoporoussilicon was successfully prepared by using CATB as surfactant. Andthen, with toluene as solvent,3-aminopropyltriethoxysilane (APTES) ascoupling agent, amino modification of the surface of the mesoporoussilica could be carried out. The sample was characterized by EDX, FTIR.Finally, the heavy metal adsorption capacity of the APTES modifiedmesoporous silicon particle were detected.
Keywords/Search Tags:Nano-silica, surface modification, dispersion polymerization, composite microspheres, adsorption
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