Qhov sib txawv tseem ceeb ntawm kev txav mus los thiab qhov sib txawv ntawm qhov sib txawv yog qhov kev txav mus los yog lub peev xwm ntawm cov khoom siv hluav taws xob txav mus los vim qhov cuam tshuam ntawm qhov hluav taws xob qhov chaw diffusion coefficient yog qhov tsis tu ncua uas piav qhia txog kev sib raug zoo ntawm molar flux thiab concentration gradient..
Kev txav mus los yog lub peev xwm ntawm cov khoom siv hluav taws xob kom txav mus los ntawm qhov nruab nrab raws li cov lus teb rau qhov hluav taws xob. Lub diffusion coefficient yog qhov sib npaug ntawm cov molar flux (vim molecular diffusion) thiab cov concentration gradient ntawm hom tshuaj.
Mobility yog dab tsi
Kev txav mus los yog lub peev xwm ntawm cov khoom siv hluav taws xob kom txav mus los ntawm qhov nruab nrab raws li cov lus teb rau qhov hluav taws xob. Lub tshuab hluav taws xob no rub cov khoom siv hluav taws xob. Hauv cov ntsiab lus no, cov khoom siv hluav taws xob feem ntau yog electrons lossis protons. Peb tuaj yeem cais cov ions sib txawv raws li lawv qhov kev txav mus los; Thaum qhov kev sib cais no ua tiav nyob rau hauv cov roj theem, nws yog hu ua ion mobility spectrometry, thiab yog tias nws nyob hauv lub xeev ua kua, peb tuaj yeem hu nws electrophoresis.
Thaum muaj cov nqi them rau hauv cov roj lossis cov kua hauv lub xeev uas tshwm sim ntawm qhov chaw hluav taws xob tsis zoo, cov khoom siv hluav taws xob tuaj yeem ua kom nrawm rau qhov nrawm uas hu ua qhov nrawm nrawm. Kev qhia lej rau kev txav mus los yog raws li hauv qab no:
vd=µE
Nyob rau hauv qhov sib npaug no, vd yog hais txog qhov nrawm nrawm, µ hais txog kev txav mus los thiab E yog qhov loj ntawm qhov hluav taws xob. Chav ntsuas rau vd yog m/s, chav ntsuas rau µ yog m2/V.s, thiab chav ntsuas rau E yog V/m. Yog li, qhov kev txav mus los ntawm cov khoom siv hluav taws xob yog qhov piv ntawm qhov nrawm nrawm mus rau qhov loj ntawm qhov hluav taws xob.
Tsis tas li ntawd, kev txav hluav taws xob ncaj qha ncaj qha rau cov nqi hluav taws xob ntawm cov khoom siv hluav taws xob.
Diffusion Coefficient yog dab tsi?
Diffusion coefficient yog qhov sib npaug ntawm qhov sib npaug ntawm molar flux (vim molecular diffusion) thiab qhov concentration gradient ntawm hom tshuaj. Nws piav qhia txog kev tsav tsheb ntawm kev sib kis. Yog li ntawd, qhov siab dua qhov diffusion coefficient, qhov diffusion sai dua. Chav ntsuas ntawm qhov ntsuas no yog m2/s.
Feem ntau, qhov diffusion coefficient nyob ntawm qhov kub thiab txias. Hauv cov khib nyiab, qhov sib txawv ntawm qhov sib txawv ntawm qhov sib txawv tuaj yeem suav nrog siv qhov sib npaug Arrhenius. Ib yam li ntawd, peb tuaj yeem siv qhov sib npaug Stokes-Einstein los xam qhov ntsuas kub ntawm qhov sib txawv ntawm cov kua dej. Hauv cov pa roj, kev sib raug zoo ntawm diffusion coefficient thiab kub tuaj yeem txiav txim siab siv Chapman-Enskog txoj kev xav.
Kev Sib Raug Zoo Ntawm Mobility thiab Diffusion Coefficient
Kev txav mus los thiab qhov sib txawv ntawm qhov sib txawv yog cov ntsiab lus zoo sib xws. Ntawm no, hluav taws xob kev txav mus los muaj feem cuam tshuam nrog qhov sib txawv ntawm cov qauv qauv los ntawm kev sib npaug hauv qab no. Nws yog hu ua Einstein kev sib raug zoo.
µ=(q/kT)D
Hauv qhov sib npaug no, µ yog qhov txav mus los, q yog tus nqi hluav taws xob, k yog Boltzmann tas li, T yog qhov kub ntawm cov pa, thiab D yog qhov sib txawv. Yog li ntawd, nyob ntawm qhov kub thiab txias ntawm cov khoom siv hluav taws xob ntawm cov khoom siv hluav taws xob, qhov kev txav mus los yog ncaj qha proportional rau diffusion coefficient.
Qhov Sib Txawv Ntawm Mobility thiab Diffusion Coefficient
Qhov sib txawv tseem ceeb ntawm kev txav mus los thiab qhov sib txawv ntawm qhov sib txawv yog qhov kev txav mus los yog lub peev xwm ntawm cov khoom siv hluav taws xob txav mus los vim qhov cuam tshuam ntawm qhov hluav taws xob qhov chaw diffusion coefficient yog qhov tsis tu ncua uas piav qhia txog kev sib raug zoo ntawm molar flux thiab concentration gradient..
Cov lus hauv qab no qhia txog qhov sib txawv ntawm kev txav mus los thiab qhov sib txawv ntawm qhov sib piv rau ib sab ntawm kev sib piv.
Summary – Mobility vs Diffusion Coefficient
Kev txav mus los thiab qhov sib txawv ntawm qhov sib txawv yog ob yam tshuaj lom neeg. Qhov sib txawv tseem ceeb ntawm kev txav mus los thiab diffusion coefficient yog tias kev txav mus los yog lub peev xwm ntawm cov khoom siv hluav taws xob txav mus los vim qhov cuam tshuam ntawm qhov hluav taws xob qhov chaw diffusion coefficient yog qhov tsis tu ncua uas piav qhia txog kev sib raug zoo ntawm molar flux thiab concentration gradient.
