molecular sieve ndi porous chuma chimene chili ndi mabowo ang'onoang'ono, ofanana kukula kwake.Zimagwira ntchito ngati sieve yakukhitchini, kupatula pamlingo wa molekyulu, kulekanitsa zosakaniza za gasi zomwe zimakhala ndi mamolekyu amitundu yambiri.Mamolekyu ang'onoang'ono okha kuposa pores angadutse;pamene mamolekyu akuluakulu amatsekeka.Ngati mamolekyu omwe mukufuna kuwalekanitsa ndi ofanana, sieve ya molekyulu imathanso kupatukana ndi polarity.Sieves amagwiritsidwa ntchito m'njira zosiyanasiyana ngati chinyezi chochotsa ma desiccants ndikuthandizira kupewa kuwonongeka kwa zinthu.
Mitundu ya Sieves Molecular
Masieve a mamolekyulu amabwera m'mitundu yosiyanasiyana monga 3A, 4A, 5A ndi 13X.Manambala amatanthauzira kukula kwa pore ndi mankhwala a sieve.Ma ion a potaziyamu, sodium, ndi calcium amasinthidwa kuti azitha kuwongolera kukula kwa pore.Pali mitundu yosiyanasiyana ya ma meshes mu sieve zosiyanasiyana.Sieve ya molekyulu yokhala ndi ma meshes ochepa imagwiritsidwa ntchito kulekanitsa mpweya, ndipo imodzi yokhala ndi ma meshes ambiri imagwiritsidwa ntchito pazamadzimadzi.Magawo ena ofunikira a sieve ya maselo amaphatikiza mawonekedwe (ufa kapena mkanda), kachulukidwe kachulukidwe, milingo ya pH, kutentha kwatsopano (kuyambitsa), chinyezi, ndi zina zambiri.
Sieve ya Molecular vs. Silika Gel
Gel silika ingagwiritsidwenso ntchito ngati chinyezi chochotsa desiccant koma ndi yosiyana kwambiri ndi sieve ya maselo.Zinthu zosiyanasiyana zomwe zingaganizidwe posankha pakati pa ziwirizi ndi zosankha za msonkhano, kusintha kwa kuthamanga, kuchuluka kwa chinyezi, mphamvu zamakina, kutentha kwa kutentha, etc. Kusiyana kwakukulu pakati pa sieve ya molekyulu ndi gel silika ndi:
Mlingo wa adsorption wa sieve ya molekyulu ndi yayikulu kuposa ya silika gel.Izi zili choncho chifukwa sieve ndi chinthu chowumitsa msanga.
Sieve ya molekyulu imagwira ntchito bwino kuposa gel osakaniza pa kutentha kwambiri, chifukwa imakhala ndi mawonekedwe ofananirako omwe amamangiriza madzi mwamphamvu.
Pachinyezi chochepa cha Relative Humidity, mphamvu ya sieve ya molekyulu ndi yabwino kwambiri kuposa ya silika gel.
Mapangidwe a sieve ya molekyulu amatanthauzidwa ndipo ali ndi pores yunifolomu, pamene mawonekedwe a silika gel ndi amorphous ndi angapo osasamba pores.
Momwe Mungayambitsire Sieves za Molecular
Kuti mutsegule ma sieve a mamolekyulu, chofunikira kwambiri ndikutentha kwambiri, ndipo kutentha kuyenera kukhala kokwanira kuti adsorbate isungunuke.Kutentha kumasiyana ndi zipangizo zomwe zimapangidwira komanso mtundu wa adsorbent.Kutentha kosasintha kwa 170-315oC (338-600oF) kungafuneke pamitundu ya sieve zomwe takambirana kale.Onse zinthu kukhala adsorbed, ndi adsorbent ndi mkangano pa kutentha uku.Kuyanika ndi vacuum ndi njira yachangu yochitira izi ndipo kumafuna kutentha kochepa poyerekeza ndi kuyanika kwamoto.
Akayatsidwa, sieve akhoza kusungidwa mu chidebe cha galasi ndi parafilm wokutidwa pawiri.Izi zipangitsa kuti azitha kugwira ntchito mpaka miyezi isanu ndi umodzi.Kuti muwone ngati sieve akugwira ntchito, mutha kuwagwira m'manja mutavala magolovesi ndikuwonjezera madzi.Ngati akugwira ntchito kwathunthu, ndiye kuti kutentha kumakwera kwambiri, ndipo simungathe kuwagwira ngakhale mutavala magolovesi.
Kugwiritsa ntchito zida zachitetezo monga zida za PPE, magolovesi, ndi magalasi otetezera kumalimbikitsidwa chifukwa njira yolumikizira masieve a molekyulu imaphatikizapo kuthana ndi kutentha kwambiri ndi mankhwala, komanso zoopsa zomwe zingachitike.
Nthawi yotumiza: May-30-2023
