Cellulose yog ib tug nyuaj polysaccharide muaj ntau cov chav dej hazos sib txuas los ntawm β-1,4-glycosidic bonds. Nws yog qhov tseem ceeb tivthaiv ntawm cov nroj tsuag ntawm tes thiab muab cov ntoo hauv tes muaj zog thiab kev nruj. Vim yog lub cellulose ntev molecular thiab siab crystallinity, nws muaj kev ruaj khov muaj zog thiab insoltraction.
(1) cov khoom ntawm cellulose thiab kev nyuaj hauv kev yaj
Cellulose muaj cov khoom hauv qab no uas ua rau nws nyuaj rau yaj:
Siab Crystallinity: Lub cellulose molecular charet form ua ib lub teeb nruj kev qauv los ntawm hydrogen nyiaj thiab lub van der waals rog.
Cov qib siab ntawm polymerization: cov qib ntawm polymerization (piv txwv li ntau, feem ntau yog ib txhiab phav phav ntawm cov molecule.
Hydrogen Bond Network: Hydrogen Bonds tau dav tam sim no thiab nyob rau hauv cellulose molecular chains, ua rau nws nyuaj rau kev puas tsuaj thiab yaj los ntawm cov kuab tshuaj dav dav.
(2) reagents uas tshem cellulose
Tam sim no, cov reagents uas tuaj yeem ua kom muaj zog cellulose feem ntau suav nrog cov kab lus hauv qab no:
1. Ionic kua
Ionic kua yog kua muaj cov kua ntau thiab cov organic los yog inorganic acions, feem ntau nrog tsis muaj volatility, siab thermal stability thiab kev hloov kho siab. Qee cov kua dej ionic tuaj yeem rho tawm cellulose, thiab lub tshuab loj yog txhawm rau tawg cov pob zeb hydrogen ntawm cellulose molecular chains. Cov kua ionic uas tsis suav nrog cov cellulve muaj xws li:
1-Butyl-3-Mutterylimidazolium chloride ([BMIM] CL): Qhov txheej txheem ionic yaj ntawm cov cellulose los ntawm hydrogen daim ntawv lees txais.
1-Ethyl-3-Metylomididazolium acetate ([emim] [AC]): Qhov txheej txheem Ionic no tuaj yeem ua rau muaj kev mob siab rau hauv cov mob me.
2. Amine Oxidant daws
Amine Oxidant daws xws li kev sib xyaw ntawm Diethylamine (DEA) thiab tooj liab cov tshuaj uas tuaj yeem rho cellulose. Nws rhuav tshem cov qauv siv lead ua ntawm cov cellulose los ntawm oxidation thiab hydrogen tsev, ua kom lub cellulose molecular saw softer thiab ntau soluble.
3. Lithium chloride-dimethylacetamide (Laij Teb Laij Teb (mac)
Cov Licl-DMAC (lithium chloride-dimethylacitamide) system yog ib qho ntawm cov txheej txheem classic rau cov cellolving cellulose. Daim ntawv tso cai muaj peev xwm ua kev sib tw rau hydrogen bonds, yog li rhuav tshem cov hlua khau ntawm cov molecules, thaum DMAC raws li cov huab tais tuaj yeem cuam tshuam zoo nrog lub cellulose molecular.
4. Hydrochloric acid / zinc chloride tov
Lub hydrochloric acid / zinc chloride tov yog qhov tseeb pom tias reagent uas tuaj yeem tshem cellulose. Nws tuaj yeem tawm cellulose los ntawm kev sib koom ua ke cuam tshuam ntawm zinc chloride thiab hydrochloric acid puas ntawm cov pob zeb hydrogen ntawm molecules molecules. Txawm li cas los xij, cov tshuaj no yog cov khoom siv kom haum rau cov khoom siv thiab tsuas yog siv rau hauv cov ntawv thov siv.
5. Fibrinolytic enzymes
Fibrinolytic enzymes (xws li cellulases (discolve cellulose los ntawm catalyzing lub decomposition ntawm cellulose rau me me oligosaccharides thiab monosaccharides. Cov qauv no muaj ntau cov kev siv hauv cov kab ke biodegradation thiab concomass conterersion, txawm hais tias nws cov txheej txheem sib cais, tab sis ua tiav los ntawm biocatalysis.
(3) kev siv nyiaj ntawm cellulose yaj
Cov regents regents muaj cov txheej txheem sib txawv rau cov cellolving cellulose, tab sis feem ntau lawv tuaj yeem yog ua rau ob lub ntsiab mechanism:
Kev puas tsuaj ntawm hydrogen kev sib haum: kev sib tsoo hydrogen ntawm cov pob zeb molecular los ntawm kev sib tw hydrogen nyiaj tsim lossis ionic kev sib cuam tshuam, ua rau nws soluble.
Molecular Saw So: nce qhov muag muag ntawm cellulose molecular charets thiab txo cov crystallinity ntawm molecular charvees los ntawm kev ua kom lub cev lossis tshuaj txhais tau tias lawv tuaj yeem yaj nyob hauv cov kuab tshuaj.
(4) Cov kev siv ntawm cellulose yaj no
Cellulose yaj muaj cov ntawv thov tseem ceeb hauv ntau thaj teb:
Kev npaj ntawm cellulose derivatives: tom qab dissolving cellulose los npaj ntxiv cellulose los npaj cov zaub mov, uas tau siv dav hauv cov zaub mov, tshuaj, txheej txheem thiab lwm thaj teb.
Cellulose-borter cov ntaub ntawv: siv cellulose cellulose, cellulose cellulose, cellulose cellulibers, cellulose mem tes thiab lwm yam khoom siv tuaj yeem npaj tau. Cov ntaub ntawv no muaj cov khoom siv zoo thiab cov biocompatibility.
Biomass Zog: Los ntawm dissolving thiab discrading cellulose, nws tuaj yeem hloov mus rau hauv bioethanol, uas pab kom ua tiav lub zog txhim kho thiab siv lub zog txuas ntxiv dua tshiab.
Cellulose yaj yog qhov txheej txheem nyuaj nrog ntau yam tshuaj thiab lub cev mechanism. Ionic kua, amino oxidant daws teeb meem, hydrochloric accol / zinc celloly accoltions thiab cellolytic enluces tau tam sim no tau paub los ua cov neeg sawv cev rau cov cellulose. Txhua tus neeg saib xyuas muaj nws tus kheej txawv txav mechanism thiab daim ntawv thov daim teb. Nrog rau kev kawm tob ntawm lub cellulose kawg me ntsis kev ua tshuab, nws ntseeg tau ntau dua thiab ib puag ncig cov txiaj ntsig kev sib cais thiab kev txhim kho cellulose.
Lub Sijhawm Post: Jul-09-2024