Hauv kev tsim khoom thiab lub neej, silica gel tuaj yeem siv los ziab N2, cua, hydrogen, roj av [1] thiab lwm yam. Raws li kua qaub thiab alkali, desiccant tuaj yeem muab faib ua: acid desiccant, alkaline desiccant thiab neutral desiccant [2]. Silica gel zoo li yog lub tshuab ziab nruab nrab uas zoo li qhuav NH3, HCl, SO2, thiab lwm yam. Txawm li cas los xij, los ntawm qhov pom tseem ceeb, silica gel yog tsim los ntawm peb-seem intermolecular dehydration ntawm orthosilicic acid molecules, lub cev tseem ceeb yog SiO2, thiab qhov chaw nplua nuj nyob rau hauv hydroxyl pawg (saib Daim Duab 1). Qhov laj thawj vim li cas silica gel tuaj yeem nqus dej yog tias silicon hydroxyl pawg ntawm qhov chaw ntawm silica gel tuaj yeem tsim intermolecular hydrogen bonds nrog dej molecules, yog li nws tuaj yeem nqus dej thiab yog li ua lub luag haujlwm ziab. Cov xim hloov silica gel muaj cov cobalt ions, thiab tom qab cov dej adsorption ncav cuag saturation, cov cobalt ions hauv cov xim hloov silica gel dhau los ua hydrated cobalt ions, yog li ntawd xiav silica gel dhau los ua liab. Tom qab ua kom sov cov silica gel liab dawb ntawm 200 ℃ rau ib lub sijhawm, qhov hydrogen bond ntawm cov silica gel thiab cov dej molecules tawg, thiab cov silica gel uas tsis muaj xim yuav tig xiav dua, yog li daim duab qauv ntawm silicic acid thiab silica gel tuaj yeem rov siv dua raws li pom hauv Daim Duab 1. Yog li, txij li thaum qhov chaw ntawm silica gel muaj ntau pawg hydroxyl, qhov chaw ntawm silica gel kuj tseem tuaj yeem tsim cov hydrogen bonds intermolecular nrog NH3 thiab HCl, thiab lwm yam, thiab tej zaum yuav tsis muaj txoj hauv kev los ua tus desiccant ntawm NH3 thiab HCl, thiab tsis muaj daim ntawv tshaj tawm tseem ceeb hauv cov ntaub ntawv uas twb muaj lawm. Yog li cov txiaj ntsig yog dab tsi? Cov ntsiab lus no tau ua cov kev tshawb fawb sim hauv qab no.
Lub sijhawm tshaj tawm: Kaum Ib Hlis-14-2023
