激光燒蝕法制備碳納米材料與金屬氧化物納米材料.pdf

1、天津大學(xué)博士學(xué)位論文激光燒蝕法制備碳納米材料與金屬氧化物納米材料姓名：田飛申請學(xué)位級(jí)別：博士專業(yè)：材料學(xué)指導(dǎo)教師：孫景杜希文20090301AbstractABSTRACTHighenergylasercouldresultinthevaporationofmaterialsandtheformationofplasmaplumewithhightemperatureandhighpressureWhenthetemperaturean

2、dpressureoftheplasmaplumestarttodropdown，thecondensationoftheplasmawouldresultintheformationofnanomaterialsAlthoughmostofthewidelyusednanosecondpulsedlaserscouldoutputlaserbeamwithhighpowerdensitytofacilitatethesynthesis

3、ofnanomaterials，theshortpulsewidth(nanosecond)alsomeansthemadlyshorteffectiveactingtimethatisnotconducivetoproductivityThelong—pulsewidthlaser(millisecond)hasapulsewidthmilliontimeslongerthanthenanosecondlaserwhichismuch

4、ofmeaningfulforthegrowthandyieldofnanomaterialsThispaperfocusesonthepreparationofnewcarbonmaterials(nanodiamodns，carbonnanotubes，carbononions，graphene，andfluorescentcarbonnanoparticles)bythechangeofpulsewidthandstartingm

5、aterials(graphiteandcarbonblack)，introductionofcatalystusingmillisecondlaserNotonlythephysicalandchemicalconditionsgeneratedbylaserwithdifferentpulsewidthandthegrowthprocessofnanodiamondswerecomparativeanalyzed，buttheequ

6、ilibriumsizesandgrowthsizesofnanodiamondswerecalculatedbycombingthethermodynamicsanddynamicsTheorticalcalculationswereingoodagreementwithexperimentalresultsandgavereasonableexplanationontheformationofnanodiamondswithdiff

7、erentsizesAccordingtothethermodynamicsandhighresolutiontransmissionelectronmicroscoperesults，weproposedtheformationofmultiplytwiningstrtuture(MTS)ofnanodiamondsandthecorrespondinggrowththeoryCarbononionswithhydrophilicch

8、aracteristicsweresynthesizedthroughirradiatingcarbonblacksuspensionusingmillisecondpulsedlaseratroomtemperatureLaserenergyabsorptionresultedinthestructuretransformationofcarbonblackandtheformationofhydrophilicgroupsonthe

9、surfaceofcarbononionCarbononionswithhollowcoresandtheincompletegraphiticshellswereproducedfromthestartingmaterialsunderhighandlowlaserpowerdensityrespectivelyAlltheexperimentalresultsshowedthatthehydrophilicpropertiesofc

10、arbonnanoonionsorginatedfromsurfacehydrophilicligandsGraphenewithsingleormultiplylayerstructurewerepreparedusinggraphte／nanosizednickelpowder嬲startingmaterialbylaserablationCarbonnanotubesWeresynthesizedusingcarbonblack／