silicalite1晶体形貌和尺寸的调控及mfi型分子筛膜的制备

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1、万方数据keepsgrowing．WecangetsmallsizecrystalsthroughincreasingtheTPAcontentorshortenthecrystallizationtimewithnochangeintheyieldofzeolites．Thestirringmethodsalsohaveinfluencesonthecrystalssizeanddistribution．Silicalite一1crystalssynthesizedinamagneticallystirredreactorha

2、vesmallersizeandwidersizedistributionthanthosesynthesizedinarotationreactor．Intwo-stagemethod，westudiedtheaffectoftemperatureinSTAGE1(Pre-Crystallization)andSTAGE2(Crystallization)．WefoundthatthetemperatureinSTAGE1(Pre—Crystallization)hassignificanteffectsonthesizeof

3、silcialite-1particle．Wecangetbigparticlesizecrystalsin40oCor80oC．whilesmallparticlesizeintherangefrom50oC一60oC．TheparticlesizealsodecreasedwithincreaseoftimeinSTAGE1．However，theparticlesizeofsilicalite一1didnotaffectedbySTAGE2(Crystallization)．0．5肛msilicalite-1zeolite

4、saresynthesizedat60oCfor24hinSTAGE1and130oCfor3hinSTAGE2withyieldof70％．Comparedwithone-stagemethod．two-stagemethodcansynthesizesmallersilicalite-1particlewithlesscrystallizationtimeandhigheryield．2．PreparationofMFIzeolitemembranesbydifferentseedsandtheirseparationper

5、formanceMFIzeolitemembraneswerepreparedbyusingseedswithdifferentmorphology(coffin，coffinwithtwincrystal，sphere)，Si／Al(m，500，140，40)，particlesizedistributionandcontentofNa+．MFIzeolitemembranesweresynthesizedonthesurfaceofporousaluminatubeundercertainconditions，andthei

6、rmorphologiesareobservedbySEM．Pervaporationperformancesaretestedfor5wt．％ethanolfeedat60oC．Itisfoundthatmembranessynthesizedbymult-crystalmorphologyseeds(coffinwithtwincrystal，sphere)havemoretwincrystalsonthesurfacethanmono．crystalmorphologyseeds(coffin)．Itismucheasie

7、rformult—crystalmorphologyseedstosynthesizedensemembranesthanmono—crystalmorphologyseeds．Membranessynthesizedbyseeds(coffinwithtwincrystals)stillhaveslightlyhigherseparationperformance．TheseparationfactorCanreach14whenTPAOH／TEOS=0．005inthesynthesissolution．MFImembran

8、espreparedbyseedswithdifferentSi／AIratioswerealsoinvestigated．TheresultsshowthatsmallamountV万方数据ofA1wouldnotaffecttheperformancemem