北京大学高分子辐射化学18

1PEKINGUNIVERSITYPEKINGUNIVERSITY纳米材料与辐射技术纳米材料与辐射技术Fourteen2PEKINGUNIVERSITYPEKINGUNIVERSITYWhatisNanotechnology????“TheCreation,Processing,Characterization,andUtilizationofmaterial,devices,andsystemswithdimensionsoftheorderof0.1-100nm,exhibitingnovelandsignificantlyenhancedphysical,chemical,andbiologicalproperties,functions,andprocessesduetotheirnanoscalesize”.3PEKINGUNIVERSITYPEKINGUNIVERSITY纳米材料(nanostructuralmaterials)♦纳米材料(nanostructuralmaterials)是指粒径在0.1~100nm之间的微小粒子组成的体系.♦纳米微粒具有体积效应,表面效应,量子尺寸效应和宏观量子隧道效应.♦纳米材料在瓷学,光学,陶瓷,半导体,催化,医药,冶金等领域具有广泛的应用前景.4PEKINGUNIVERSITYPEKINGUNIVERSITY纳米材料的制备方法物理方法化学方法从上到下从下到上制备方法从下到上低温粉碎法超声波粉碎法冲击波破碎法水锤粉碎法高能球磨法喷雾法蒸汽快速冷却法蒸汽油面冷却法分子束外延法旋转涂层气相沉积法玻璃态合金高压晶化法气相沉淀法液相沉淀法L-B膜法溶胶-凝胶法水热/溶剂热法自组装法5PEKINGUNIVERSITYPEKINGUNIVERSITYTheapproachtoproducenanostructuredmaterialsanddevicesTheTop-Downapproach¾Tostartwiththebulkmaterialandmachinehiswaydowntothenano-scale;¾TraditionalmethodTheBottom-Upapproach¾Tostarteatthemolecularlevelandbuildupthematerialthroughthesmallclusterleveltothenanoparticleandtheassemblyofnanoparticles.¾Nanotechapproach6PEKINGUNIVERSITYPEKINGUNIVERSITY辐射技术在纳米材料制备中的应用irradiated2aq322HOe,HO,H,OH,HO,−+⎯⎯⎯⎯→iH原子和水化电子为还原性粒子,可将金属离子还原成低价金属粒子或原子,后者可进一步聚集成核,成长为纳米粒子,从溶液中沉淀出来.1.纳米金属,纳米氧化物,纳米复合材料的辐射制备Water-in-oil(W/O)Microemulsion(ME)CitiSfttCfttOilt™Composition:Surfactant,Cosurfactant,Oil,water™Waterpool:nano-sizedmicroreactorMorphologyandsizeofnanoparticles™Routinechemicalmethod:surfactant,cosurfactant,anion,andωvalue(molarratioofwatertosurfactant)canonlyaffecttheshapeofnanoparticles™ArethereanythingdifferentbetweentheroutinechemicalygmethodandtheirradiationmethodinME?e−irradiatedCH3C6H5CH3C6H5.−C10H8eoilOilC10H8C10H8.−1.Mainresourceofe−eaq−irradiated2.Theyieldofeaq−increaseswiththeincreaseofωvalue1.MainresourceofeaqNO2−WatereaqNO3−NO32Wong,M.;etal.Chem.Phys.Lett.1975,30,329.GebickiJL;etalJChemSocFaradayTrans1994903411WaterGebicki,J.L.;etal.J.Chem.Soc.FaradayTrans.1994,90,3411.Adhikari,S.;etal.J.ColloidInterfaceSci.1997,191,268.Joshi,R.;etal.Radiat.Phys.Chem.2003,66,397.IControlledReductionofCu2＋I.ControlledReductionofCu1110aq2smolL103.3CueCu−−+−+⋅⋅×=⎯→⎯+k1172smolL101.9HCuHCu−−+++⋅⋅×=+⎯→⎯+k1110aqsmolL107.2CueCu−−−+⋅⋅×=⎯→⎯+k+++→2CuCuCu2q119smolL100.5CuHHCu−−++⋅⋅×=⎯→⎯+k+⎯→⎯CuCuCu2OHOCuCuOH2,HCuOHOHCu222+⎯→⎯+⎯→⎯+++IntheW/Omicroemulsionsbasedonnonionicsurfactants,i.e.,Brij30,Brij56,orTritonX-100,theradiolyticreductionofCu2+couldbecontrolledbytheωvalue,aromaticringandanions.SummaryofthereductionproductsofCu2+underdifferentCuBr2CuCl2CuSO4Cu(NO3)2ωypconditions(absorbeddose:40kGy,doserate:40Gy/min)Cu2O9.0TritonX-100224(3)2Cu2OCuCuCu2OCuCuCuCu7.0CuCuCuCu2O9.0Brij56CuCuCu2OCuCuCu2O&Cu5.4Cu6.0Brij30CuCu2O&Cu11923aq3smolL107.9NOeNO−−−−−⋅⋅×=⎯→⎯+k2dtSO−−→+CuO40Cu2O4.5CuOCu2O116aq4smolL100.1productseSO−−⋅⋅×⎯→⎯+kaqproductseCl−−⎯→⎯+Cu2O4.0Cu2O116smolL100.1−−⋅⋅×kII.RadiolyticsynthesesofCu2Ooctahedronyy2nanocrystalsinTritonX-100basedmicroemulsionPrecursor:Cu(NO)From1to5,doserate:132.0,92.2,75.6,40.0,22.7Gy/min.Absorbeddose:20kGy.Precursor:Cu(NO3)2From1to5,doserate:132.0,92.2,75.6,40.0,22.7Gy/min.Absorbeddose:20kGySample2Absorbeddose:20kGy.III.FormationofsolidandhollowCu2Onanocubes2TolueneEthyleneglycol(EG)Precursor:Cu(NO3)2,absorbeddose:40kGy,doserate:40Gy/minTritonX-100-basedMEBrij56-basedME1.Q.D.Chen,X.H.Shen,H.C.Gao.J.ColloidInterfaceSci.,20073122722007,312,272.2.Q.D.Chen,X.H.Shen,H.C.Gao.J.ColloidInterfaceSci.,2007,308,491.3.P.He,X.H.Shen,H.C.Gao.J.ColloidInterfaceSci.,2005,284,510.4.Q.D.Chen,X.H.Shen,H.C.Gao.ColloidSurfaceA,2006,275,45.5.P.He,X.H.Shen,H.C.Gao.ActaPhys.Chim.Sin.,2004,20,12001PEKINGUNIVERSITYPEKINGUNIVERSITY辐射技术在纳米材料制备中的应用(1)多官能团单体直接辐射聚合法(2)脉冲高剂量率辐照分子内交联法2.纳米凝胶的辐射制备4HydrophilicpolymersusedtosynthesizeHydrophilicpolymersusedtosynthesizehydrogelshydrogelsFunctionalgroupsrenderingthehydrophiliccharacter:—OH,—COOH,—NH2,—CONH2,—CHNHR,—SO3H,R–O–RCH2CHCO2Poly(acrylicacid)Poly(vinylmethylether)Poly(vinylalcohol)CH2CHOHCH2CHOCH3NOCHCH2PolyvinylpyrrolidoneCH2CH2OPoly(ethyleneoxide)Poly(1-hydroxyethylmethacrylate)pHEMACH2CHCOOCH2CH2OH5RadiationRadiation--inducedinducedcrosslinkingcrosslinkingininaqueousaqueoussolutionsolutionWater-solublepolymers(PVAL,PVP,PEO,PAA,PVMEetc.)Oxygen-freesolutionsIonizingradiation:gammarays(60Co),fastelectrons(accelerator)H2Oeaq−,•OH,H•,H2O2,H2,H+,OH−ionizingradiationeaq−+N2O•OH+N2+OH−H2OH2OH2OH2OH2OH2OOHH2OHH2OH2OH2OH2OH2OH2OH2OH2O6BasicreactionsofsimplemidBasicreactionsofsimplemid--chainpolymerradicalschainpolymerradicalsH-transfer++Degradation(chainscission)Depropagation(depolymerization)DisproportionationRecombination(crosslinking)intermolecularintramolecularintermolecularintramolecular7CrossCross--linkinglinking::intermolecularintermolecularvsvs..intramolecularintramolecular11ParametersParametersthatthatcancanbebecontrolledcontrolledDoserateintramolecularintermolecularConcentrationintramolecularintermolecularDosecrosslinkdensitymeshsize01020300200400600PAADegreeofswellingDose/kGy12ExperimentalconditionspromotingExperimentalconditionspromotingintramolecularin