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Ordered Mesoporous Poly Alcohol Assembly And Synthesis Of Ordered Mesoporous Carbon Materials With Functional Modification,

Posted on:2010-05-09Degree:DoctorType:Dissertation
Country:ChinaCandidate:Y P DiFull Text:PDF
GTID:1111360302979294Subject:Inorganic Chemistry
Abstract/Summary:PDF Full Text Request
Mesoporous materials with diversified compositions and mesostructure have attracted widespread attention because of their unique properties,such as electromagnetism,photoelectricity,catalysis etc.,and thus their promising application in the fields of solid-catalysis,photocatalysis,fuel cells,supercapacitors,and so on. Porous polymer is a class of advanced materials and possesses enormous potential for many high-tech applications,however,the report of ordered mesoporous polymer is still rare,Therefore,developing new methods for the preparation of highly ordered mesoporous polymers can not only enrich the component of ordered mesoporous materials,but also open an avenue for their application in catalysis,adsorption, separation,bioreactors and microelectrophoresis.Carbon based materials are of great interest owning to the advantages of low cost, large surface area,high stability,and electroconductibility.Modification of the structural and surface properties of carbon materials has been studied more and more intensely,in order to meet the demands of various practical applications.Although the approach to modify mesoporous carbons from "soft-template" strategy can refer to the successful experience of conventional "hard-template" originated carbons,it still unavoidably encounters new problems and challenges.This thesis includes three major parts.In the first part,a series of ordered mesoporous carbons have been prepared with various hydrocarbons via a hard template method.The effect of carbon source on the carbon walls and the performance as electrodes in EDLC has been investigated.In the second part,ordered mesoporous poly(furfuryl alcohol)(PFA)-silica composites was prepared by an organosilane-assisted strategy,and its adsorption property for toluene was examined. In the third part,it focuses on the functionalization of mesoporous carbon prepared from the direct triblock-copolymer-templating approach.The hybrid mesoporous carbons possess advanced properties for application,such as high adsorption ability and magnetic separability.In chapter 2,a series of ordered mesoporous carbons have been prepared with SBA-15 as hard template and sucrose,furfuryl alcohol,naphthalene and anthracene as carbon precursors.OMCs prepared from sucrose and furfuryl alcohol display amorphous pore walls,and large surface areas.The functional groups in the precursors like sucrose and furfuryl alcohol can be preserved on carbon surfaces after the carbonization at low temperatures but would be removed at high temperatures. The graphitizable precursors like anthracene are suitable for deriving the OMCs with graphitic walls.Therefore,the OMCs originated from sucrose and furfuryl alcohol behave the highest capacitances at a carbonization of 700℃,and a declination at high temperatures.Anthracene derived OMCs has the lowest capacitance carbonized at 700℃C,and a steady enhancement when heated at high temperatures.In chapter 3,ordered mesoporous poly(furfuryl alcohol)(PFA)-silica composites were synthesized with an organosilane-assisted approach by employing TEOS, 3-(triethoxysilyl)furan and furfuryl alcohol as precursors,triblock copolymer F127 as a structure-directing agent via an EISA process.The organic-inorganic nanocomposites have ordered 2-D centered-rectangular(c2mm) mesostructure even the organic content in the samples is as high as 60 wt%.Their surface area,pore volume and pore size are as high as 510 m2/g,0.54 cm3/g and 5.7 nm.The adsorption performances of the hybrid materials for toluene were also conducted.Because of the hydrophobic property,which is affinity with toluene molecules,the PFA-silica nanocomposite,having similar surface area with ordered mesoporous silica,shows twice larger adsorption quantity than the latter one.In chapter 4,ordered mesoporous carbons with magnetic frameworks have been prepared via "one-pot" block-copolymer self-assembly strategy associated with a direct carbonization process from resol,ferric citrate and triblock copolymer F127. The effects of iron loading on framework,pore features and magnetic properties of resultant mesostructured maghemite/carbon composites were investigated.Further H2O2 oxidation treatment of the magnetic nanocomposites endows plenty of oxygen-containing functional groups on the carbon surface,which improves their hydrophilic properties.Such modified nanocomposites with hydrophilic and magnetic framework show evidently improved adsorption properties of water and fuchsin base dye molecules in water and an easy separation procedure.In chapter 5,magnetic separable ordered mesoporous carbons with high surface area and large pore size were synthesized by multi-component self-assembly of resol, nickel nitrate,TEOS and triblock copolymer F127,followed by a direct carbonization and silica removal process.The obtained ordered mesoporous Ni/C composites show high surface area(1580 m2/g),large pore volume(1.42 cm3/g) and pore size(6.8 nm). The adsorption amount of this material for dye molecule fuchsin base is 3 times larger than FDU-15.
Keywords/Search Tags:mesoporous carbon, hard template, mesoporous silica, self-assembly, poly furfuryl alcohol, magnetic material, soft template, composite
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