HPMC (Hydroxypropyl Methyl Cellulose) yog ib hom organic polymer additive lug siv nyob rau hauv kev npaj ntawm ceramics. Ceramic daim nyias nyias yog dav siv nyob rau hauv cov kua filtration, sib cais thiab purification vim lawv zoo txhua yam muaj zog, corrosion kuj thiab kub kuj. Txawm li cas los xij, qhov permeability ntawm ceramic membranes yog ib qho ntawm cov tseem ceeb cuam tshuam rau lawv cov kev ua tau zoo. Txhawm rau txhim kho cov permeability ntawm ceramics, ntxiv cov additives tsim nyog tau dhau los ua ib qho tseem ceeb.
1. Lub luag haujlwm ntawm HPMC hauv kev npaj cov khoom siv ceramic
Pore qauv kev cai
Thaum lub sij hawm npaj ntawm ceramics, HPMC plays lub luag hauj lwm nyob rau hauv regulating lub pore qauv. Los ntawm kev ntxiv HPMC rau cov slurry, nws muaj peev xwm tswj tau qhov tsim ntawm pores hauv ceramic membrane. HPMC yuav decompose thaum lub sij hawm kub-kub sintering los tsim ib tug ntau yam pore qauv, uas yog ib qho tseem ceeb rau kev txhim kho permeability ntawm ceramics. Lub uniformity ntawm pore loj faib thiab qhov nce ntawm porosity ua rau daim nyias nyias muaj permeability ntau dua thaum tuav lub zog, yog li ua kom cov permeation ntawm cov kua.
Txo qhov kub ntawm sintering
Lub sintering kub ntawm cov ceramic membrane ncaj qha cuam tshuam nws microstructure. HPMC tuaj yeem txo qhov kub ntawm sintering ntawm cov khoom siv ceramic, kom lawv tuaj yeem tsim cov qauv membrane nrog zoo permeability ntawm qhov kub thiab txias. Qhov txo qis ntawm sintering kub tsis tsuas yog pab kom txuag tau lub zog, tab sis kuj ua rau qeeb qhov kev loj hlob ntau ntawm cov nplej, yog li tswj kev ruaj ntseg thiab permeability ntawm lub pore qauv.
Txhim kho qhov fluidity ntawm slurry
Raws li ib qho ntxiv, HPMC tuaj yeem txhim kho fluidity ntawm ceramic slurry thiab txhim khu kev ua tau zoo ntawm slurry thaum lub sij hawm npaj daim nyias nyias. Los ntawm kev txhim kho cov khoom rheological ntawm cov slurry, cov slurry tuaj yeem muab faib ua ntau qhov sib npaug ntawm qhov chaw ntawm lub substrate los tsim cov ceramic membrane nrog cov tuab tuab thiab nruab nrab ntom. Qhov zoo formability no kuj pab txhim kho lub permeability ntawm lub kawg membrane.
2. Mechanism ntawm HPMC los txhim kho permeability
Cov qauv molecular ntawm HPMC muaj ntau pawg hydroxyl thiab methoxy, uas ua rau nws muaj cov dej solubility zoo thiab cov khoom ua yeeb yaj kiab. Hauv kev npaj cov khoom siv ceramic, HPMC ua lub luag haujlwm hauv qab no:
Pore-forming tus neeg sawv cev lub luag haujlwm
HPMC tau txais cov thermal decomposition thaum lub sij hawm sintering txheej txheem los tsim cov roj. Cov pa roj no tsim muaj ntau qhov pores zoo hauv daim nyias nyias, ua tus neeg sawv cev pore-forming. Lub cim ntawm pores pab lub fluidity ntawm cov kua uas dhau los ntawm ceramic membrane, yog li txhim kho cov permeability ntawm daim nyias nyias. Tsis tas li ntawd, qhov decomposition ntawm HPMC kuj tseem tuaj yeem zam qhov pore blockage ntawm daim nyias nyias thiab ua kom cov pores tsis muaj kev cuam tshuam.
Txhim kho hydrophilicity ntawm daim nyias nyias
Cov pab pawg hydroxyl hauv HPMC tsim cov ntawv cog lus hydrogen nrog cov dej molecules, ua rau cov ceramic membrane nto ntau hydrophilic. Tom qab lub hydrophilicity ntawm daim nyias nyias tau txhim kho, cov kua yog yooj yim dua rau diffuse thiab nkag mus rau ntawm daim nyias nyias, uas ua rau muaj txiaj ntsig zoo rau kev nkag mus hauv kev kho dej thiab pom. Tsis tas li ntawd, hydrophilicity kuj tseem tuaj yeem txo cov pa phem thiab thaiv los ntawm cov kua rau ntawm daim nyias nyias, yog li txhim kho cov permeability ntxiv.
Uniformity thiab stability ntawm daim nyias nyias
Qhov sib ntxiv ntawm HPMC tuaj yeem ua rau lub microstructure ntawm ceramic membrane ntau yam. Thaum lub sij hawm sintering txheej txheem, lub xub ntiag ntawm HPMC muaj peev xwm ua tau zoo inhibit qhov sib sau ua ke ntawm ceramic hmoov, ua rau lub pore qauv ntawm daim nyias nyias nyias, yog li txhim kho cov permeability ntawm daim nyias nyias. Nyob rau tib lub sijhawm, HPMC tuaj yeem txhim kho cov slurry thaum lub sij hawm npaj cov txheej txheem membrane, tiv thaiv cov slurry los ntawm precipitating thiab stratifying thaum lub sij hawm molding txheej txheem, thiab yog li xyuas kom meej lub uniformity ntawm cov ceramic membrane.
3. HPMC daim ntawv thov piv txwv thiab tsom xam cov nyhuv
Hauv qee qhov kev siv tswv yim, qhov sib ntxiv ntawm HPMC txhim kho cov permeability ntawm ceramics. Kev kho dej ua piv txwv, los ntawm kev ntxiv HPMC rau hauv cov txheej txheem ntawm cov txheej txheem ntawm ceramics, cov ntaub ntawv membrane npaj qhia cov dej ntws siab thiab kev ua haujlwm zoo heev. Hauv cov txheej txheem ntawm kev kho dej phwj tuaj, qhov permeability ntawm daim nyias nyias yog qhov tseem ceeb hauv kev txiav txim siab kev kho mob. Ceramic membrane nrog HPMC ntxiv tuaj yeem ua tiav cov dej ntws tawm ntawm qhov tsis tshua muaj siab, uas txhim kho kev kho mob zoo thiab txo cov nqi khiav haujlwm.
HPMC kuj tau siv dav hauv ceramic membrane sib cais tshuab hauv cov khoom noj, tshuaj, thiab lwm yam. Nws optimizes qhov pom thiab sib cais los ntawm daim nyias nyias los ntawm kev txhim kho cov permeability ntawm daim nyias nyias. Piv txwv li, hauv cov txheej txheem lim mis, HPMC txhim kho qhov permeability ntawm daim nyias nyias, ua kom cov txheej txheem pom zoo dua thiab tsis txhob poob cov as-ham.
Raws li ib tug multifunctional additive, HPMC plays lub luag hauj lwm tseem ceeb nyob rau hauv kev npaj ntawm ceramics. Nws zoo txhim kho cov permeability ntawm ceramics los ntawm kev tswj cov pore qauv, txo cov sintering kub, thiab txhim kho cov fluidity ntawm slurry. Lub pore-forming tus neeg sawv cev cuam tshuam ntawm HPMC, kev txhim kho ntawm hydrophilicity thiab kev txhim kho cov uniformity ntawm lub membrane qauv ua rau cov ceramic membrane qhia zoo heev permeability nyob rau hauv ntau yam pom thiab sib cais daim ntaub ntawv. Nrog rau kev txhim kho txuas ntxiv ntawm cov khoom siv hluav taws xob ceramic, HPMC yuav siv ntau lub teb los ua ib qho ntxiv, muab ntau txoj hauv kev rau kev nce qib ntawm cov tshuab membrane.
Post lub sij hawm: Sep-30-2024