Qhov sib txawv tseem ceeb ntawm tus lej nruab nrab thiab qhov hnyav nruab nrab qhov hnyav molecular yog tias tus lej nruab nrab molecular hnyav yog hais txog cov feem ntawm molecules hauv cov qauv polymer whereas qhov hnyav nruab nrab molecular hnyav yog qhov hnyav ntawm cov molecules hauv cov qauv polymer.
Tsis zoo li cov tebchaw dawb huv, cov polymers tsim los ntawm kev sib xyaw ntawm cov molecules sib txawv (cov tebchaw ntshiab muaj cov molecules zoo tib yam, tab sis cov polymers muaj cov molecules tsis zoo ib yam). Piv txwv li, cov qauv polymer tuaj yeem muaj cov hlua khi ntev ntev, tab sis nrog cov saw ntev sib txawv hauv txhua lub molecule. Yog li ntawd, peb siv qhov nruab nrab sib txawv los qhia txog qhov hnyav ntawm polymer molecular. Tus lej nruab nrab molecular hnyav thiab qhov hnyav nruab nrab molecular hnyav yog ob hom.
Tus lej Nruab Nrab Molecular Luj yog dab tsi?
Tus lej nruab nrab molecular hnyav yog qhov feem ntawm molecules hauv cov qauv polymer. Nws yog ib txoj hauv kev los txiav txim siab molecular mass ntawm polymer. Nws muab qhov nruab nrab ntawm cov molecular masses ntawm tus kheej macromolecules. Hauv lwm lo lus, nws yog tag nrho qhov hnyav ntawm tus qauv muab faib los ntawm tus lej ntawm cov molecules hauv cov qauv.
Daim duab 01: Qhov hnyav nruab nrab molecular hnyav ib txwm siab dua tus lej nruab nrab molecular hnyav.
Peb tuaj yeem pom tus nqi ntawm qhov ntsuas no siv qhov sib npaug hauv qab no:
Mn=∑ NiMi / ∑ N i
Ntawm no, Mn yog tus lej nruab nrab molecular hnyav, Ni yog tus naj npawb ntawm cov molecules muaj M i hnyav hauv cov qauv polymer, thiab Mi yog qhov hnyav ntawm ib qho molecule ntawm tus qauv. Peb tuaj yeem txiav txim siab tus lej nruab nrab molecular hnyav siv gel permeation chromatography, viscometry thiab colligative txoj kev xws li vapor siab osmometry.
Nyhav Qhov Nruab Nrab Molecular Luj yog dab tsi?
Qhov hnyav nruab nrab molecular hnyav yog qhov hnyav ntawm cov molecules hauv cov qauv polymer. Nws yog lwm txoj hauv kev los txiav txim siab qhov molecular loj ntawm cov polymer. Nws muab qhov nruab nrab ntawm cov molecular masses ntawm tus kheej macromolecules hauv cov qauv polymer. Peb tuaj yeem pom qhov ntsuas no siv qhov sib npaug hauv qab no:
Mw=∑ NiMi2 / ∑ NiMi
Qhov twg Mw yog qhov hnyav nruab nrab molecular hnyav, Ni yog tus naj npawb ntawm cov molecules ntawm molecular mass M iPeb tuaj yeem txiav txim siab qhov ntsuas no siv lub teeb pom kev zoo li qub, lub kaum sab xis me me neutron scattering, X-ray scattering, thiab sedimentation tshaj tawm. Qhov tseem ceeb tshaj, qhov hnyav nruab nrab molecular hnyav ib txwm ntau dua qhov hnyav nruab nrab molecular hnyav vim tias cov molecules loj hauv cov qauv hnyav dua li cov molecules me.
Dab tsi yog qhov txawv ntawm tus lej nruab nrab thiab qhov hnyav nruab nrab molecular hnyav?
Vim tias cov qauv polymer muaj cov qauv sib txawv, peb tsis tuaj yeem muab qhov hnyav molecular ntawm polymer. Yog li, peb siv qhov nruab nrab ntawm qhov sib txawv los qhia qhov hnyav molecular ntawm polymer. Tus naj npawb nruab nrab thiab qhov hnyav nruab nrab molecular hnyav yog ob hom. Qhov sib txawv tseem ceeb ntawm tus lej nruab nrab thiab qhov hnyav nruab nrab qhov hnyav molecular yog tias tus lej nruab nrab molecular qhov hnyav yog hais txog cov feem ntawm molecules hauv cov qauv polymer thaum qhov hnyav nruab nrab molecular hnyav yog qhov hnyav ntawm cov molecules hauv cov qauv polymer. Lwm qhov sib txawv ntawm tus lej nruab nrab thiab qhov hnyav nruab nrab qhov hnyav molecular yog tias peb tuaj yeem txiav txim siab tus lej nruab nrab qhov hnyav molecular siv gel permeation chromatography, viscometry thiab colligative txoj kev xws li vapor siab osmometry thaum peb tuaj yeem txiav txim siab qhov hnyav nruab nrab molecular hnyav uas siv lub teeb static tawg, lub kaum sab xis me me. neutron scattering, X-ray scattering, thiab sedimentation tshaj tawm.
Cov hauv qab no qhia qhov sib txawv ntawm tus lej nruab nrab thiab qhov hnyav nruab nrab molecular hnyav hauv daim ntawv.
Summary – Tus lej nruab nrab vs Qhov hnyav nruab nrab Molecular Nyhav
Tus lej nruab nrab thiab qhov hnyav nruab nrab qhov hnyav molecular yog ob yam uas peb siv los qhia qhov hnyav molecular ntawm cov qauv polymer. Qhov sib txawv tseem ceeb ntawm tus lej nruab nrab thiab qhov hnyav nruab nrab qhov hnyav molecular yog tias tus lej nruab nrab molecular qhov hnyav yog hais txog cov feem ntawm molecules hauv cov qauv polymer whereas qhov hnyav nruab nrab molecular hnyav yog qhov hnyav ntawm cov molecules hauv cov qauv polymer.
