Qhov sib txawv tseem ceeb ntawm Knudsen thiab molecular diffusion yog Knudsen diffusion cuam tshuam nrog kev sib tsoo ntawm cov roj molecules nrog cov phab ntsa pore, whereas molecular diffusion koom nrog kev txav ntawm cov molecules ntawm ib lub cev mus rau lwm qhov raws li qhov concentration gradient.
Diffusion yog hais txog kev txav ntawm cov molecules (tshwj xeeb yog cov roj molecules) los ntawm lub cev. Cov txheej txheem no tuaj yeem pom nyob rau hauv ob hom: Knudsen diffusion thiab molecular diffusion.
Knudsen Diffusion yog dab tsi?
Knudsen diffusion yog qhov sib txawv uas tshwm sim thaum qhov ntsuas qhov ntev ntawm lub kaw lus piv rau lossis me dua li qhov nruab nrab ntawm txoj kev pub dawb ntawm cov khoom cuam tshuam. Lo lus no yog siv feem ntau hauv physics thiab chemistry, thiab nws tau raug hu ua tus kws tshawb fawb Martin Knudsen.
Thaum xav txog kev txav mus los (tshwj xeeb tshaj yog, kev nthuav dav) ntawm cov roj molecules los ntawm cov kab me me me me, yog tias txoj kev tsis pub dawb ntawm cov pa diffusing molecules loj dua lub pore txoj kab uas hla, ces txhais tau tias qhov ntom ntawm cov pa roj. tsawg heev, thiab cov roj molecules zoo li sib tsoo nrog cov phab ntsa pore piv rau kev sib tsoo ntawm cov molecules. Cov txheej txheem no yog hu ua Knudsen diffusion lossis Knudsen flow.
Daim duab 01: Ib qho Molecule hauv lub tog raj kheej Pore thaum Knudsen Diffusion
Ntxiv thiab, peb tuaj yeem txhais tus lej Knudsen, uas yog qhov ntsuas zoo ntawm qhov tseem ceeb ntawm Knudsen diffusion. Yog tias tus lej no ntau dua 1, nws txhais tau tias Knudsen diffusion yog qhov tseem ceeb rau qhov system ntawd. Xyaum, tus lej no tsuas yog siv tau rau cov pa roj. Qhov no yog vim hais tias txoj kev tsis pub dawb ntawm cov molecules hauv cov kua lossis cov khoom muaj zog tsawg heev.
Molecular Diffusion yog dab tsi?
Diffusion yog qhov txav ntawm cov molecules los ntawm thaj tsam ntawm qhov siab mus rau qhov tsis tshua muaj siab ntawm qhov concentration gradient. Cov kev txav no tshwm sim hauv tib txoj kev daws teeb meem. Cov yam ntxwv uas cuam tshuam rau qhov concentration gradient cuam tshuam rau qhov diffusion thiab.
Cov lus tsa suab no raug txiav tawm thaum qhov sib npaug ntawm ob thaj chaw sib npaug ntawm txhua qhov chaw. Qhov no txhais tau tias qhov kev txav no tshwm sim kom txog thaum lub concentration gradient ploj mus. Tom qab ntawd cov molecules kis mus rau txhua qhov chaw hauv cov tshuaj.
Daim duab 02: Kev nthuav tawm ntawm Ions Ntawm Ob Qhov Systems
Tus nqi ntawm kev txav ntawm cov molecules los ntawm kev sib kis yog qhov ua haujlwm ntawm qhov kub thiab txias, viscosity ntawm cov pa roj (los yog kua) thiab qhov loj me. Feem ntau, molecular diffusion piav qhia txog cov net flux ntawm molecules los ntawm ib cheeb tsam ntawm siab concentration mus rau ib tug tsawg concentration. Thaum xav txog ob lub tshuab, A1 thiab A2, uas nyob ntawm qhov kub thiab txias thiab muaj peev xwm sib pauv cov molecules ntawm lawv, kev hloov pauv ntawm lub zog muaj peev xwm ntawm ob lub tshuab no tuaj yeem tsim lub zog ntws los ntawm ib qho mus rau lwm qhov (los ntawm A1. mus rau A2 los yog vice versa) vim hais tias ib qho system ib txwm nyiam tsawg zog thiab siab entropy xeev. Qhov no tsim ib lub xeev ntawm molecular diffusion.
Qhov txawv ntawm Knudsen thiab Molecular Diffusion yog dab tsi?
Muaj ob hom kev sib kis xws li Knudsen diffusion thiab molecular diffusion. Qhov sib txawv tseem ceeb ntawm Knudsen thiab molecular diffusion yog tias Knudsen diffusion cuam tshuam nrog kev sib tsoo ntawm cov roj molecules nrog cov phab ntsa pore, thaum molecular diffusion cuam tshuam nrog kev txav ntawm cov molecules ntawm ib lub cev mus rau lwm qhov raws li qhov concentration gradient.
Summary – Knudsen vs Molecular Diffusion
Muaj ob hom kev sib kis xws li Knudsen diffusion thiab molecular diffusion. Qhov sib txawv tseem ceeb ntawm Knudsen thiab molecular diffusion yog tias Knudsen diffusion cuam tshuam nrog kev sib tsoo ntawm cov roj molecules nrog cov phab ntsa pore, thaum molecular diffusion cuam tshuam nrog kev txav ntawm cov molecules ntawm ib lub cev mus rau lwm qhov raws li qhov concentration gradient.
