Lub molecular sieve yog ib yam khoom siv uas muaj qhov me me, sib npaug. Nws ua haujlwm zoo li lub sieve hauv chav ua noj, tsuas yog ntawm qhov ntsuas molecular, cais cov roj sib xyaw uas muaj ntau qhov loj me. Tsuas yog cov molecules me dua li qhov pores thiaj li hla tau; thaum, cov molecules loj dua raug thaiv. Yog tias cov molecules koj xav cais yog tib qhov loj me, lub molecular sieve kuj tuaj yeem cais los ntawm polarity. Sieves siv rau hauv ntau yam kev siv ua cov desiccants tshem tawm cov dej noo thiab pab tiv thaiv kev puas tsuaj ntawm cov khoom.
Hom Molecular Sieves
Cov molecular sieves muaj ntau hom xws li 3A, 4A, 5A thiab 13X. Cov lej suav qhia qhov loj ntawm lub qhov thiab cov tshuaj sib xyaw ntawm lub sieve. Cov ions ntawm potassium, sodium, thiab calcium raug hloov pauv hauv cov khoom sib xyaw kom tswj tau qhov loj ntawm lub qhov. Muaj ntau tus lej sib txawv ntawm cov meshes hauv cov sieves sib txawv. Lub molecular sieve nrog cov lej me dua ntawm cov meshes siv los cais cov pa roj, thiab ib qho nrog ntau lub meshes siv rau cov kua. Lwm cov yam ntxwv tseem ceeb ntawm cov molecular sieves suav nrog daim ntawv (hmoov lossis hlaws), qhov ceev ntawm cov khoom loj, pH theem, qhov kub rov ua dua tshiab (kev ua kom muaj zog), dej noo, thiab lwm yam.
Molecular Sieve vs. Silica Gel
Silica gel kuj siv tau ua cov tshuaj desiccant uas tshem cov dej noo tab sis nws txawv ntawm lub molecular sieve heev. Cov yam sib txawv uas yuav tsum xav txog thaum xaiv ob qho no yog cov kev xaiv sib dhos, kev hloov pauv ntawm qhov siab, qib dej noo, lub zog kho tshuab, qhov kub thiab txias, thiab lwm yam. Qhov sib txawv tseem ceeb ntawm lub molecular sieve thiab silica gel yog:
Qhov nrawm ntawm kev nqus ntawm lub molecular sieve yog siab dua li ntawm silica gel. Qhov no yog vim tias lub sieve yog ib qho khoom siv qhuav sai.
Lub molecular sieve ua haujlwm zoo dua li silica gel hauv qhov kub siab, vim nws muaj cov qauv sib xws dua uas khi dej kom ruaj khov.
Thaum cov av noo qis, lub peev xwm ntawm lub molecular sieve zoo dua li ntawm silica gel.
Cov qauv ntawm lub molecular sieve yog txhais thiab muaj cov qhov hws sib xws, thaum cov qauv ntawm silica gel yog amorphous thiab ntau qhov hws tsis sib xws.
Yuav Ua Li Cas Qhib Cov Sieves Molecular
Yuav kom ua kom cov molecular sieves ua haujlwm tau, qhov yuav tsum tau ua yog raug rau qhov kub thiab txias heev, thiab cua sov yuav tsum siab txaus rau cov adsorbate kom vaporize. Qhov kub yuav txawv nrog cov khoom siv uas raug adsorbed thiab hom adsorbent. Yuav tsum muaj qhov kub tas li ntawm 170-315oC (338-600oF) rau cov hom sieves uas tau tham ua ntej. Ob qho tib si cov khoom siv uas raug adsorbed, thiab cov adsorbent raug cua sov ntawm qhov kub no. Kev ziab hauv lub tshuab nqus tsev yog ib txoj hauv kev ua qhov no sai dua thiab xav tau qhov kub qis dua piv rau kev ziab hluav taws.
Thaum twg siv tau lawm, cov sieves yuav khaws cia rau hauv lub thawv iav uas muaj ob txheej parafilm qhwv. Qhov no yuav ua rau lawv siv tau txog rau lub hlis. Yuav kom paub tseeb tias cov sieves puas siv tau, koj tuaj yeem tuav lawv hauv koj txhais tes thaum koj hnav hnab looj tes thiab ntxiv dej rau hauv. Yog tias lawv siv tau tag nrho, ces qhov kub yuav nce siab heev, thiab koj yuav tsis tuav tau lawv txawm tias koj hnav hnab looj tes los xij.
Kev siv cov khoom siv kev nyab xeeb xws li cov khoom siv PPE, hnab looj tes, thiab tsom iav kev nyab xeeb yog qhov pom zoo vim tias cov txheej txheem ntawm kev ua kom cov molecular sieves ua haujlwm cuam tshuam nrog kev daws teeb meem kub thiab tshuaj lom neeg, thiab cov kev pheej hmoo cuam tshuam.
Lub sijhawm tshaj tawm: Tsib Hlis-30-2023
