Txoj Kev Hloov Kev Txiav Txim Siab ntawm Sodium Carboxymethyl Cellulose

Kev txiav txim siab qib ntawm kev hloov pauv (DS) ntawm sodium carboxymethyl cellulose (CMC) yog qhov tseem ceeb rau kev tswj kom zoo thiab ua kom muaj kev sib luag hauv nws cov khoom thiab kev ua haujlwm. Muaj ntau txoj hauv kev tuaj yeem siv los txiav txim siab DS ntawm CMC, nrog rau cov txheej txheem titration thiab spectroscopic feem ntau ua haujlwm. Nov yog cov lus piav qhia ntxaws ntxaws ntawm txoj kev titration rau kev txiav txim siab DS ntawm sodium CMC:

1. Txoj Cai:

• Txoj kev titration cia siab rau cov tshuaj tiv thaiv ntawm pawg carboxymethyl hauv CMC thiab cov qauv kev daws teeb meem ntawm lub hauv paus muaj zog, feem ntau yog sodium hydroxide (NaOH), nyob rau hauv kev tswj xyuas.
• Carboxymethyl pawg (-CH2-COOH) hauv CMC react nrog NaOH los tsim sodium carboxylate (-CH2-COONa) thiab dej. Qhov twg ntawm cov tshuaj tiv thaiv no yog proportional rau tus naj npawb ntawm carboxymethyl pawg nyob rau hauv CMC molecule.

2. Reagents thiab khoom siv:

• Sodium hydroxide (NaOH) txheej txheem kev daws teeb meem ntawm kev paub txog concentration.
• CMC qauv.
• Acid-base indicator (piv txwv li, phenolphthalein).
• Burette.
• Conical khob.
• Cov dej distilled.
• Stirrer los yog magnetic stirrer.
• Kev ntsuas ntsuas.
• pH meter los yog daim ntawv qhia.

3. Cov txheej txheem:

1. Kev npaj ua qauv:
   • Ntsuas tus nqi tshwj xeeb ntawm CMC tus qauv kom raug siv qhov ntsuas ntsuas.
   • Dissolve cov qauv CMC hauv ib lub ntim ntawm cov dej distilled paub los npaj ib qho kev daws teeb meem paub txog concentration. Xyuas kom meej sib tov kom tau ib homogeneous tov.
2. Titration:
   • Pipette ntsuas qhov ntim ntawm CMC tov rau hauv lub khob conical.
   • Ntxiv ob peb tee ntawm cov kua qaub-puag qhia (piv txwv li, phenolphthalein) rau lub khob. Qhov ntsuas yuav tsum hloov xim ntawm qhov kawg ntawm qhov titration, feem ntau nyob ib ncig ntawm pH 8.3-10.
   • Titrate CMC tov nrog tus qauv NaOH tov los ntawm lub burette nrog tas li stirring. Sau qhov ntim ntawm NaOH tov ntxiv.
   • Txuas ntxiv titration mus txog rau thaum xaus, qhia los ntawm kev hloov xim tsis tu ncua ntawm qhov ntsuas.
3. Kev suav:
   • Xam cov DS ntawm CMC siv cov qauv hauv qab no:
   $��=�\times �\times �NaOH�CMC$

   DS = mCMCV × N × MNaOH

   Qhov twg:

   • $��$

     DS = Degree of Hloov.

   • $�$

     V = Volume of NaOH solution used (in liters).

   • $�$

     N = Normality of NaOH solution.

   • $�NaOH$

     MNaOH = Molecular Luj ntawm NaOH (g/mol).

   • $�\; CMC$

     mCMC = Mass of CMC qauv siv (hauv grams).

4. Txhais lus:
   • Tus lej DS suav nrog tus lej nruab nrab ntawm pawg carboxymethyl ib chav tsev piam thaj hauv CMC molecule.
   • Rov ua qhov kev ntsuam xyuas ntau zaus thiab xam qhov nruab nrab DS kom ntseeg tau qhov tseeb thiab kev ntseeg siab ntawm cov txiaj ntsig.

4. Kev txiav txim siab:

• Xyuas kom zoo calibration ntawm cov cuab yeej thiab standardization ntawm reagents kom raug.
• Siv cov tshuaj NaOH nrog kev saib xyuas vim nws yog caustic thiab tuaj yeem ua rau kub hnyiab.
• Ua qhov titration nyob rau hauv kev tswj xyuas kom txo tau qhov yuam kev thiab hloov pauv.
• Txheeb xyuas cov txheej txheem siv cov qauv siv los yog kev sib piv nrog rau lwm txoj kev siv tau.

Los ntawm kev ua raws li txoj kev titration no, qib ntawm kev hloov pauv ntawm sodium carboxymethyl cellulose (CMC) tuaj yeem txiav txim siab kom raug, muab cov ntaub ntawv tseem ceeb rau kev tswj kom zoo thiab tsim cov hom phiaj hauv ntau yam lag luam.