Silica gel yog ib yam khoom tseem ceeb, siv dav hauv kev lag luam thiab lub neej txhua hnub kom nqus dej noo thiab av noo. Nws cov tshuaj lom neeg tshwj xeeb thiab lub cev muaj zog ua rau nws xaiv qhov kev xaiv desiccant.
I. Cov qauv thiab cov khoom ntawm silica geldesiccant
Silica gel hlaws yog cov khoom ntxeem tau tsuas yog tsim los ntawm silicic acid gel, nrog cov tshuaj formula ntawm SiO2.nH2O. Cov yam ntxwv ntawm silica gel desiccant yog tias nws muaj ntau cov micropores sab hauv, uas tsim ib qho chaw loj loj, uas yog lub hauv paus ntawm nws lub peev xwm nqus dej noo. Qhov pore loj ntawm granular silica gel tuaj yeem nyob ntawm ob peb nanometers mus rau ntau pua nanometers, uas ua rau nws tuaj yeem nqus cov molecules ntawm ntau qhov ntau thiab tsawg, suav nrog cov dej molecules. Lwm yam khoom tseem ceeb ntawm silica gel yog nws cov tshuaj inertness, uas txhais tau hais tias nws tsis hnov mob nrog cov tshuaj feem ntau thiab ruaj khov txawm tias nyob rau qhov kub thiab txias. Tsis tas li ntawd, gel silica muaj cov yam ntxwv ntawm non-toxicity, odorlessness, thiab non-corrosiveness.
II. Moisture absorption txoj cai
Lub hauv paus ntsiab lus ntawm kev nqus dej noo ntawm silica gel desiccant yog tsim los ntawm ob txheej txheem: lub cev adsorption thiab tshuaj adsorption.
1. Lub cev adsorption
Lub cev adsorption yog hais txog kev sib txuas tsis yog covalent ntawm silica gel pores thiab dej molecules vim yog lub zog sib xyaw. Thaum cov dej molecules nyob rau hauv cov huab cua los rau hauv kev sib cuag nrog cov nto ntawm nws, cov molecules yog attracted los ntawm lub electrostatic quab yuam nyob rau hauv lub pores thiab nkag mus rau sab hauv ntawm lub pores. Txij li thaum silica gel muaj thaj tsam loj heev, nws tuaj yeem nqus tau ntau cov dej molecules.
2. Tshuaj adsorption
Tshuaj adsorption yog hais txog cov tshuaj tiv thaiv ntawm silica gel thiab dej molecules. Txawm hais tias silica gel nws tus kheej tsis hnov mob chemically nrog dej molecules, nyob rau hauv tej yam kev mob, xws li kub kub los yog muaj lwm yam chemicals, nws yuav hnov mob nrog tej yam khoom hydrolysis kom ua tiav cov tshuaj adsorption ntawm noo noo.
III. Kev faib tawm ntawm silica gel desiccant
Silica gel desiccant tuaj yeem muab faib ua dawb gel silica, xiav xiav silica, txiv kab ntxwv gel silica thiab alumina gel silica. Dawb silica gel thiab alumina silica gel yog tsis qhia, thaum xiav silica gel thiab txiv kab ntxwv silica gel yog qhia silica gel. Thaum lub sij hawm nqus dej, lub xiav yuav tig liab liab, thaum lub txiv kab ntxwv yuav tig ntsuab.
IV. Kev siv ntawm silica gel desiccant
Silica gel particle yog dav siv nyob rau hauv ntau yam teb vim nws tshwj xeeb hygroscopic zog thiab kev nyab xeeb. Xws li cov nkev roj dehydration, roj thiab roj rov qab hydrophobicity, cov khoom siv hluav taws xob, cov khoom ntim tshuaj, cov khoom siv thiab cov twj paj nruag, cua compression systems, thiab lwm yam.
Nyeem cov lus qhia ntxiv txog silica gel desiccant
