Qhov Tseem Ceeb Qhov txawv - Cellulose vs Hemicellulose
Cellulose thiab hemicellulose yog ob hom natural polymers uas feem ntau pom nyob rau hauv cov nroj tsuag cell phab ntsa thiab yog cov khoom tseem ceeb ntawm cov ntaub ntawv lignocellulosic. Tab sis, ob lub ntsiab lus no txawv ntawm cov tshuaj muaj pes tsawg leeg thiab cov qauv. Qhov sib txawv tseem ceeb ntawm cellulose thiab hemicellulose yog cellulose yog ib qho organic polysaccharide molecule whereas hemicellulose yog ib tug matrix ntawm polysaccharides.
Cellulose yog dab tsi
Cellulose yog cov organic polysaccharide molecule nrog cov qauv molecular (C 6H10O 5)nNws muaj cov kab sib txuas ntawm ntau pua mus rau txhiab tus D-glucose units. Cellulose yog ib tug natural polymeric compound pom nyob rau hauv ntau yam ntaub ntawv ntuj; Piv txwv li, nws yog cov qauv ntawm cov phab ntsa ntawm cov phab ntsa hauv cov nroj tsuag ntsuab. Nws tuaj yeem pom nyob rau hauv ntau hom algae hom. Cellulose yog cov organic polymer tshaj plaws hauv ntiaj teb. Ntau yam ntuj tsim muaj ntau hauv cellulose; Piv txwv li, cov ntsiab lus cellulose ntawm ntoo, paj rwb fiber, thiab qhuav hemp yog 40-50%, 90%, thiab 57% feem.
Hemicellulose yog dab tsi
Hemicellulose, tseem hu ua polyose, yog ib qho matrix ntawm polysaccharides, xws li arabinoxylans, uas muaj nyob nrog cellulose nyob rau hauv yuav luag tag nrho cov nroj tsuag cell phab ntsa. Nws yog polysaccharide uas muaj nyob rau hauv biomass ntawm feem ntau cov nroj tsuag; txog 20% -30% qhuav hnyav ntawm cov nroj tsuag. Hemicellulose, ua ke nrog cellulose, muab lub cev thiab lub zog ntawm cov phab ntsa ntawm tes. Ntxiv nrog rau cov piam thaj, lwm yam khoom siv hauv hemicelluloses yog xylose, galactose, mannose, rhamnose, thiab arabinose. Hemicellulose muaj luv luv chains ntawm 500 thiab 3000 qab zib units nrog ib tug branched qauv.
Qhov txawv ntawm Cellulose thiab Hemicellulose yog dab tsi?
qauv:
Cellulose: Cellulose yog ib qho tsis muaj ceg polymeric molecule thiab muaj 7,000–15,000 qabzib molecules ib polymer.
Hemicellulose: Hemicellulose muaj cov saw luv luv ntawm 500-3,000 qab zib units thiab nws yog cov khoom siv polymer.
Tshuaj muaj pes tsawg leeg:
Parameter |
Nyob zoo Cellulose |
YHemicellulose |
| Subunits | D-Pyran qabzib units |
D-Xylose mannose, L-arabinose galactose Yglucuronic acid |
| Cov nyiaj nruab nrab ntawm cov subunits | "-1, 4-Glycosidic bonds |
-1, 4-Glycosidic bonds hauv main chains; "-1.2-, "-1.3-, "-1.6-glycosidic bonds hauv cov saw hlau |
| YPolymerization | Ntau pua txog kaum tawm txhiab units. Nws muaj cov qauv tsis sib xws. | Tsawg dua 200 units. Nws muaj ib ceg qauv. |
| YPolymer | Yβ-Glucan | YPolyxylose, Galactoglucomannan (Gal-Glu-Man), glucomannan (Glu-Man) |
| Composition | Peb-dimensional linear molecular tsim ntawm thaj tsam crystalline thiab thaj tsam amorphous. |
Peb-dimensional Inhomogeneous molecular nrog thaj tsam me me crystalline. |
Properties:
Cellulose: Cellulose muaj zog, crystalline qauv thiab nws tiv taus hydrolysis. Hauv kev sib piv rau hemicellulose, qhov no muaj qhov hnyav molecular. Cellulose ua raws li cov khoom txhawb nqa hauv cov phab ntsa ntawm cov nroj tsuag.
Hemicellulose: Hemicellulose muaj qhov sib txawv, amorphous qauv nrog lub zog me me. Nws tuaj yeem yooj yim hydrolyzed los ntawm dilute acid los yog hauv paus thiab zoo li los ntawm myriad hemicellulose enzymes. Hemicellulose yog bio-degradable thiab degraded los ntawm kev sib koom ua ke ntawm ob peb enzymes ntawm qee cov kab mob thiab cov fungi. Nws muaj qhov hnyav dua molecular piv rau cellulose.
Daim ntawv thov:
Cellulose: Feem ntau ntawm cov cellulose yog siv los tsim cov ntawv thiab ntawv. Cov khoom me me tau hloov mus rau ntau yam khoom siv derivative xws li cellophane thiab rayon. Kev hloov pauv ntawm cellulose rau hauv biofuels xws li cellulosic ethanol yog nyob rau theem kev tshawb fawb los siv los ua lwm yam roj av. Ntoo pulp thiab paj rwb yog lub ntsiab cellulose qhov chaw rau kev siv.
Hemicellulose: Nws yog siv los ua cov yeeb yaj kiab thiab cov gels hauv ntim. Txij li thaum, hemicellulose yog non-toxic thiab bio-degradable nws yog siv nyob rau hauv edible films rau txheej cov khoom noj kom muaj kev ntxhib los mos, saj thiab lub qhov ncauj. Thiab tseem, nws yog siv los ua cov khoom noj fiber ntau.
Definition:
Synergistic action: Ib qho txiaj ntsig tshwm sim ntawm ob lossis ntau tus neeg sawv cev, cov koom haum, yam, lossis cov tshuaj uas ua rau muaj kev cuam tshuam ntau dua li cov txiaj ntsig ntawm lawv tus kheej.
