Kev Tshawb Nrhiav Kev Tshawb Fawb
Raws li lub ntuj, ntau thiab txuas ntxiv ntxiv, cellulose engang pom cov kev sib tw zoo heev vim nws tsis tau yaj thiab txwv nyuaj cov khoom. Lub siab muaj crystallinity thiab high-ceev hydrogen daim ntawv cog lus nyob rau hauv lub cellulose qauv ua rau nws tsis tau yaj, thiab insoluble hauv dej thiab feem ntau cov kuab tshuaj. Lawv cov derivatives yog tsim los ntawm qhov Esterification thiab Eretification ntawm cov pawg hydroxyl ntawm cov khoom siv roj polymer, thiab yuav ua rau qee cov khoom sib txawv nrog cov pob zeb ntuj sib piv. Lub hereforification cov tshuaj tiv thaiv ntawm cellulose muaj peev xwm tsim ntau cov dej cellulose muaj kev hais txog (HEC) Dej-soluble CE tuaj yeem tsim cov polymers hydrogen-bonded polymers nrog polycarboxylic acids thiab polyphenols.
Txheej-los ntawm-txheej sib dhos (lbl) yog txoj kev zoo rau kev npaj polymer composite nyias cov yeeb yaj kiab. Cov hauv qab no feem ntau yog piav qhia txog kev sib txoos LBL Tshawb cov txiaj ntsig ntawm PH ntawm cov yeeb yaj kiab thickness, thiab qhov sib txawv sib txawv ntawm pH ntawm zaj duab xis ntawm zaj duab xis thiab kev sib txawv, thiab txhim kho cov dej tsis nqus dej ntawm CE / PAA.
Sim cov khoom siv:
Polyacrylic acid (paa, mw = 450,000). Lub viscosity ntawm 2wt. Methylcellulose (MC, A 2WT. HydroxyPropyl cellulose (HPC, A AQUE OQUOAGE NROG VISCOST NTAWM 000 MPANAY NTAWM 400 MPAMOY LOS NTAWM IB TUG ME ALTIONS LOS NTAWM 2.5).
Zaj duab xis:
Npaj los ntawm ua kua crystal txheej ntawm silicon ntawm 25 ° C. Cov kev kho mob ntawm cov swb matrix yog raws li hauv qab no: akaus hauv dej acidic (h2vol / vol) ob peb zaug kom txog rau ob peb zaug kom txog rau thaum lub p pauj, thiab thaum kawg qhuav nrog ntshiab nitrogen. LBL los ua ke yog ua siv siv tshuab siv tsis siv neeg. Lub substrate yog hloov soaked nyob rau hauv ce daws (0.2 mg / ml) thiab paa daws (0.2 mg / ml), txhua qhov kev daws teeb meem yog soaked rau 4 min. Peb yaug soaks ntawm 1 min hauv dej deadized tau ua ntawm txhua qhov kev daws teeb meem kom tshem tawm cov pa roj av uas tau txuas. Qhov txiaj ntsig p p ntawm cov kev daws teeb meem thiab kev muab tshuaj yaug ob leeg tau hloov kho rau PH 2.0. Cov yeeb yaj kiab npaj tau yog hais txog li (CE / PAA) n, uas n uas yog qhov chaw ntawm lub rooj sib tham sib dhos. (HEC / PAA) 40, (MC / PAA) 30 thiab (HPC / PAA) 30 tau yog npaj.
Zaj duab xis:
Nyob ze-qub kev xav txog kev pom zoo tau sau tseg thiab raug txheeb xyuas nrog Nanocalc-XR lub hiav txwv optics, thiab cov tuab ntawm cov yeeb yaj kiab tso rau ntawm silicon tau ntsuas. Nrog rau sab nraum silicon subictrate raws li keeb kwm yav dhau los, ft-ir spectrum ntawm cov zaj duab xis nyias ntawm silicon substrate tau sau rau ntawm Nicolet 8700 Infrared Spectrometer.
Hydrogen Bermanen Bondactions ntawm PAA thiab CES:
Sib dhos ntawm HEC, MC thiab HPC nrog PAA rau hauv lbl cov yeeb yaj kiab. Lub infrared spectra ntawm hec / PAA, MC / PAA thiab HPC / PAA muaj nyob hauv daim duab. Lub zog IR cov cim ntawm PAA thiab CES tuaj yeem pom tau meej meej hauv IRECTA ntawm HEC / PAA, MC / PAA thiab HPC / PAA. FT-IR Spectroscopy tuaj yeem tshawb xyuas cov hydrogen daim ntawv cog lus ntawm PAA thiab CES los ntawm kev saib xyuas kev ua haujlwm ntawm cov yam ntxwv nqus cov bands. Cov hydrogen sib khi ntawm CES thiab PAA feem ntau tshwm sim ntawm hydroxyl oxygen ntawm CES thiab COO pab pawg ntawm PAA. Tom qab hydrogen bond yog tsim, ncab peak liab hloov mus rau qhov tsawg zaus.
Ib lub ncov ntawm 1710 CM-1 tau pom rau ntshiab paa hmoov. Thaum Polyacrylamide tau sib sau ua ke nrog CES sib txawv, cov PAA, MC / PAA cov yeeb yaj kiab tau nyob ntawm 1718 CM-1, 1720 CM-1 thiab 1724 CM-1, feem. Piv nrog cov ntshiab paa hmoov, lub ncov ntev ntawm HPC / PAA, MC / PAA cov yeeb yaj kiab hloov los ntawm 14, 10 thiab 8 cm-1, feem. Lub hydrogen bond ntawm howher oxygen thiab kis cuam tshuam nrog kev sib tw hydrogen ntawm cov pab pawg beoh. Qhov ntau hydrogen khi tsim ntawm PAA thiab CE, qhov ntau dua cov kev hloov pauv ntawm CE / PAA hauv IR Spectra. HPC muaj qhov siab tshaj plaws ntawm hydrogen daim ntawv cog lus nyuaj, PAA thiab MC nyob hauv nruab nrab, thiab HEC yog qhov qis tshaj.
Kev loj hlob kev coj cwj pwm ntawm cov yeeb yaj kiab ntawm PAA thiab CES:
Zaj duab xis-ua tus cwj pwm ntawm PAA thiab Ces thaum LGB yog tshawb fawb siv QCM thiab Spectral interferometry. QCM yog qhov ua tau zoo rau kev soj ntsuam zaj duab xis kev loj hlob hauv situ thaum thawj ob peb lub rooj sib tham. Spectral interferomers yog qhov tsim nyog rau cov yeeb yaj kiab loj dua 10 mus.
HEC / PAA zaj duab xis tau pom txoj kab kev loj leeb thoob plaws hauv cov txheej txheem kev sib dhos hauv kev sib dhos thaum ua ke thiab tom qab ntawd hloov mus rau hauv kab kev loj hlob. Nyob rau hauv txoj kab kev loj hlob cheeb tsam, cov qib siab dua ntawm cov nyom, qhov ntau dua qhov kev loj hlob tuab ib sib dhos.
Cov nyhuv ntawm kev daws Ph ntawm zaj duab xis kev loj hlob:
Tus lej ntawm cov kev daws teeb meem cuam tshuam rau kev loj hlob ntawm hydrogen bonded polymer sib xyaw ua yeeb yaj kiab. Raws li lub zog polyelectrolyte, PAA yuav muaj ionized thiab cuam tshuam tsis zoo raws li cov ph txog ph ntawm cov kev daws teeb meem hydrogen. Thaum cov degree ntawm iona ntawm PAA tau mus txog qee theem, PAA tsis tuaj yeem sib sau ua ke rau hauv zaj duab xis nrog hydrogen daim ntawv lees txais cov neeg lees paub hauv lbl.
Cov yeeb yaj kiab tuab txo qis nrog kev nce ntawm ph, thiab cov yeeb yaj kiab tuab poob qis dua tam sim ntawd ntawm PH2,5 HPC / PAA thiab PHAA. Qhov tseem ceeb ntawm HPC / PAA yog li ntawm PH 3.5, thaum ntawd Hec / PAA yog li 3.0. Qhov no txhais tau tias thaum cov kev sib dhos ua ke yog siab dua 3.5, cov yeeb yaj kiab HPC / PAA tsis tuaj yeem tsim, thiab thaum cov yeeb yaj kiab ntawm HEC / PAA. Vim muaj kev sib haum ntau dua ntawm hydrogen kev sib cog lus ntawm HPC / PAA Membrane, tus chij tseem ceeb ntawm HPC / PAA membrane yog siab tshaj li ntawm HEC / PAA IDE. Hauv kev daws teeb meem ntsev, qhov tseem ceeb PH txiaj ntsig ntawm cov compues tsim los ntawm hec / PAA, MC / PAA thiab HPC / PAA tau txog 2.9, 3.2 thiab 3.2, feem. Qhov tseem ceeb PHUJ HPC / PAA siab dua li ntawm HEC / PAA, uas yog ua raws li ntawm LBL MINE.
Dej kev nqus kev ua tau ntawm CE / PAA MEMBRANE:
CES yog nplua nuj nyob hauv pawg hydroxyl yog li nws muaj cov dej nqus dej zoo thiab dej khaws cia. Siv HEC / PAA MAILANE ua ib qho piv txwv, tus adsorption muaj peev xwm ntawm hydrogen-bonded CE / PAA MEMBRANE rau dej hauv ib puag ncig tau kawm. Cov cwj pwm los ntawm Spectral cuam tshuam, cov yeeb yaj kiab thickness nce li cov zaj duab xis nqus dej. Nws tau muab tso rau hauv ib puag ncig nrog cov av noo uas muaj cov av noo Cov yeeb yaj kiab tau qhuav hauv lub tshuab nqus tsev (40 ° C) rau 24 h kom ua tiav cov dej noo.
Raws li cov av noo nce, cov yeeb yaj kiab thickens. Nyob rau hauv qhov tsawg humidity thaj tsam ntawm 30% -50%, qhov tuab loj hlob yog qeeb. Thaum cov av noo siab tshaj 50%, cov tuab loj hlob sai heev. Piv nrog cov hydrogen-bonded pvolon / paa membrane, HEC / PAA MEMBRANE tuaj yeem nqus tau dej ntau ntxiv los ntawm ib puag ncig. Raws li kev mob ntawm tus txheeb ze vaum ntawm 70% (25 ° C), lub thickening ntau ntawm pvon / paa zaj duab xis yog li 4 / paa zaj duab xis yog siab li 18%. Cov txiaj ntsig tau qhia tau tias txawm hais tias qee cov nyiaj ntawm AUS pawg hauv kev tsim cov hologogen sib koom ua ke, muaj ntau cov pawg sib cuam tshuam nrog dej hauv ib puag ncig. Yog li ntawd, HEC / PAA system muaj cov dej zoo nqus dej.
Hauv kev xaus
(1) HPC / PAA system nrog hypogen high hydrogen kev loj hlob ntawm lawv, MC / PAA yog nyob hauv nruab nrab, thiab HEC / PAA yog qhov qis tshaj.
(2) HEC / PAA zaj duab xis tau pom txoj kab kev npaj thoob plaws hauv thawj ob lub voj voog, thiab tom qab ntawd hloov mus rau hauv txoj kab kev loj hlob hom.
(3) Txoj kev loj hlob ntawm CE / PAA zaj duab xis muaj kev vam khom muaj zog ntawm kev daws Ph. Thaum cov kev daws teeb meem pH yog siab tshaj nws qhov tseem ceeb, PAA thiab CE tsis tuaj yeem sib sau ua ke rau hauv zaj duab xis. Cov kev sib sau ua ke (PAA daim nyias nyias yog cov kev daws teeb meem.
(4) Vim tias lub CE / PAA zaj duab xis yog nplua nuj nyob rau hauv oh thiab cooh, kev kho cua sov ua rau nws hla. Tus ntoo khaub lig-Txuas CE / PAA MEMBRANE muaj qhov ruaj khov zoo thiab yog insoluble hauv p p kev daws teeb meem siab.
(5) Tus CE / PAA zaj duab xis tau muaj peev xwm ua tau zoo rau dej nyob hauv ib puag ncig.
Lub Sijhawm Post: Feb-18-2023