Qhov sib txawv tseem ceeb ntawm alpha thiab gamma alumina yog tias alpha alumina muaj thaj tsam qis heev thiab yuav luag tsis ntxeem tau, qhov gamma alumina muaj thaj chaw siab nrog qee qhov porosity.
Alumina lossis aluminium oxide nanoparticles tsuas yog ib pawg ntawm cov hlau oxides uas muaj lub zog dielectric siab thiab lwm yam thermal zog uas tuaj yeem ua rau muaj zog hluav taws xob ntxiv, hardness, thiab muaj zog hlau thiab alloys. Cov nanoparticles no yog spherical zoo li tus thiab tshwm li cov hmoov dawb. Tsis tas li ntawd, cov khoom no tuaj yeem siv rau hauv kev sib xyaw ua ke, ceramics, laser muaju, cov khoom siv txiav, cov raj rauv, cov ntaub ntawv polishing, thiab lwm yam. Yeej, muaj ob hom particles li alpha thiab gamma alumina.
Alpha Alumina yog dab tsi?
Alpha alumina yog alpha daim ntawv ntawm txhuas oxide. Alpha alumina los yog alpha aluminium oxide crystallizes nyob rau hauv cov qauv corundum qhov twg cov pa oxygen txoj hauj lwm kwv yees li hexagonal kaw packing thiab trivalent txhuas cations occupying 2/3rds ntawm lub octahedral qhov chaw. Raws li qee qhov kev tshawb fawb tshawb fawb, cov qauv corundum thiab nws qhov chaw pab pawg muaj rau cov qauv hauv cov hexagonal unit cell.
Thaum xav txog cov qauv ntawm alpha alumina, nws yog trigonally tsim nrog ABAB kev npaj ntawm cov dav hlau ntawm oxygen raws C-txoj kev. Cov khoom no theem nrog kub ntawm 1050 - 1100 degrees Celsius. Raws li kev suav X-ray diffraction, alpha alumina muaj crystallite zoo li ntawm 33 nm. Cov tshuaj no pom nws qhov chaw siab tshaj plaws ntawm 266 m 2/ g ntawm 400 degrees Celsius. Qhov chaw qis tshaj plaws tuaj yeem pom ntawm 1100 degrees Celsius li 5.0 m2/g. Tag nrho cov pore ntim tau ntawm 600 degrees Celsius.
Daim duab 01: Alumina Nano Fibers
Alpha alumina, vim nws cov khoom siv thermal, tuaj yeem siv rau hauv kev tsim cov yas, ceramics, thiab lwm yam khoom hauv lub Hoobkas. Nws pab txhim kho qhov sib piv ceev hauv ceramics thiab ua haujlwm los tiv thaiv kev qaug zog thermal. Tsis tas li ntawd, nws muaj kev ua haujlwm siab thiab muaj ntau yam kev siv hauv kev tsim cov hluavtaws rubies, aluminium garnets, thiab lwm yam ntaub.
Gamma Alumina yog dab tsi?
Gamma alumina yog gamma daim ntawv ntawm txhuas oxide. Nws muaj lub cubic zoo thiab qhia tau hais tias lub ntsej muag-centered cubic qauv. Cov qauv tuaj yeem muab tau raws li ABCABC oxygen stacking. Hauv gamma alumina, muaj qhov chaw seem ntawm aluminium (III) posts. Nws kuj tseem nyob tsis tau tsuas yog txoj haujlwm octahedral nkaus xwb tab sis kuj yog txoj haujlwm tetrahedral los ntawm theem ntawm kev nyob uas tseem muaj kev sib cav.
Gamma alumina theem nrog kub ntawm 400 txog 600 degrees Celsius. Raws li X-ray diffraction xam, pawg crystallite nyob rau hauv thaj tsam ntawm 5.0 txog 10.0 nm. Hom alumina no muaj qhov taw tes qis ntawm chav tsev kub, thiab peb tuaj yeem siv nws los tsim cov yas sapphires siv cov txheej txheem thermal melting.
Gamma alumina tuaj hauv daim ntawv ntawm nanopowder, muaj xim dawb, nrog rau purity ntawm 99.97%, thiab qhov loj ntawm 20 - 30 nm. Nws yog cov khoom siv dav siv nrog cov ntawv thov uas muaj xws li absorbents mus rau heterogenous catalysis vim nws qhov chaw siab thiab acidic deg zog.
Qhov txawv ntawm Alpha thiab Gamma Alumina yog dab tsi?
Alpha thiab gamma alumina yog cov qauv polymorphic tseem ceeb ntawm alumina. Qhov sib txawv tseem ceeb ntawm alpha thiab gamma alumina yog tias alpha alumina muaj qhov chaw qis heev thiab yuav luag tsis ntxeem tau, hos gamma alumina muaj thaj chaw siab nrog qee qhov porosity. Ntxiv mus, alpha alumina yog amorphous thaum gamma alumina yog acidic.
Cov hauv qab no qhia txog qhov sib txawv ntawm alpha thiab gamma alumina hauv daim ntawv tabular rau kev sib piv ntawm ib sab.
Summary – Alpha vs Gamma Alumina
Alpha alumina yog alpha daim ntawv ntawm txhuas oxide, thaum gamma alumina yog gamma daim ntawv ntawm txhuas oxide. Qhov sib txawv tseem ceeb ntawm alpha thiab gamma alumina yog tias alpha alumina muaj thaj chaw qis heev, thiab nws yuav luag tsis ntxeem tau, qhov gamma alumina muaj thaj chaw siab nrog qee qhov porosity.
