资源描述：
《ZnSCu发光粉的包膜处理研究》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。
1、哈尔滨工业大学工学硕f:学位论文摘要本文采用流态化化学气相淀积(CVD)包覆法对ZnS:Cu电致发光粉进行包膜处理，研究了发光粉的流态化行为，通过SEM.EDS,XRD,EPMA等测试手段对包膜处理后的发光粉进行鉴定与表征，考察了包覆过程中工艺条件对包覆物含量和结构的影响，探讨了流态化CVD包覆发光粉的过程与机理。试验结果表明，ZnS:Cu发光粉属于GeldartC类颗粒，其流化过程包括节涌、沟流、平稳流化三个阶段;发光粉平稳流化机理是粉体发生自团聚;发光粉流化时发生二次聚团;流化后床层结构可分为气泡相和团聚相两相。研究发现，
2、反应温度在125'C--175℃之间时，Ti02的含量变化不是很大;Ti0:的含t与TiC14进料浓度近似成正比，这说明包覆过程中TiC14蒸气基本完全水解;Ti02的含f与反应时间呈线性关系.研究流态化CVD包覆发光粉的过程与机理表明，包覆过程可分为四个阶段，存在成膜与成核包覆的竞争;由于实验中进料浓度较大，故以成核包覆为主。TEM,SEM,EDS,EPMA测试结果表明，在发光粉表面确实淀积一层均匀的Ti02膜;XRD证实Ti02膜为无定型相;对包膜处理后发光粉进行了粒度分析，结果表明发光粉平均粒径增大，分散性能有所改善。关
3、键词ZnS:Cu发光粉:电致发光:流态化:化学气相淀积(CVD)哈尔滨工业大学工学硕l:学位论文AbstractCopper-activatedzincsulfidephosphorparticleswereencapsulatedbythefluidizedchemicalvapordeposition(CVD)method,thefluidizedbehaviorofphosphorhadbeenstudied,Titania(Ti02)coatingsonthesurfaceofphosphorparticleswere
4、identifiedandcharacterizedbymeansofSEM,EDS,XRD,EPMAmeasurements.Theefectofcoatingprocessontitaniacontentandtheconfigurationoffilmwasinvestigated，theprocessandmechanismofencapsulatingphosphorparticleswerediscussed.Theexperimentresultsshowthatcopper-activatedzincsulfi
5、dephosphorparticlesbelongtoGeldartCParticles,Theprocessoffluidizationincludesthreesteps:plugging,channelling,fluidizing.Themechanismofsmoothfluidizationisthatthephosphorparticlesagglomeratespontaneously.Whenphosphorparticlesfluidized,thesecondagglomerateswereformed,
6、andthebedwasdividedbythebubblingandtheagglomeratingphase.Theinvestigationshowedthatthetitaniccontentchangedlittlewhenthecoatingtemperaturewaslocatedbetween125℃一175'C.ThecontentoftitaniawasindirectproportiontotheconcentrationofTiCl4approximatively,thisshowsthatTiC14v
7、aporinthebedwashydrolyzedultimately.Thecontentoftitaniawaslinedwithcoatingtime.Theprocessandmechanismofcoatingphosphorparticlesinafluidizedbedshowedthattheprocesscanbecomposedoffoursteps,thereexistedcompetitionbetweenhomogeneousmembraneandheterogeneousnucleation.Ino
8、urexperiments,encapsulationwasdominatedwithheterogeneousnucleationonthesurface.TheresultsofTEM,SEM,EDS,EPMA,XRDmeasurementsshowedthatphosp
