I-Cellulose yi-polysaccharide eyinkimbinkimbi eyenziwe ngamayunithi amaninzi e-glucose adityaniswe ngamabhondi e-β-1,4-glycosidic. Yeyona nxalenye iphambili yeendonga zeeseli zesityalo kwaye inika iindonga zeeseli zesityalo inkxaso eyomeleleyo yesakhiwo kunye nokuqina. Ngenxa yekhonkco elide le-cellulose ye-molecular chain kunye ne-crystallinity ephezulu, inozinzo olomeleleyo kunye nokunganyibiliki.
(1) Iipropati zeselulosi kunye nobunzima bokuchithwa
ICellulose inezi mpawu zilandelayo ezenza kube nzima ukunyibilika:
Ubukhazikhazi obuphezulu: Amatsheyina emolekyuli eselulosi enza ulwakhiwo lwelathisi eqinileyo ngokusebenzisa iibhondi zehydrogen kunye namandla evan der Waals.
Iqondo eliphezulu lepolymerization: Iqondo lepolymerization (okt ubude betsheyina lemolekyuli) yeselulosi iphezulu, ngokuqhelekileyo isuka kumakhulu ukuya kumawaka eeyunithi zeglucose, nto leyo eyandisa ukuzinza kwemolekyuli.
Inethiwekhi ye-Hydrogen bond: Iibhondi ze-Hydrogen zikhoyo ngokubanzi phakathi kunye nangaphakathi kwimixokelelwane ye-cellulose ye-molecular, okwenza kube nzima ukutshatyalaliswa kunye nokunyibilikiswa zizinyibilikisi ngokubanzi.
(2) Ii-reagents ezinyibilikisa i-cellulose
Okwangoku, ii-reagents ezaziwayo ezinokunyibilikisa i-cellulose ngokufanelekileyo ziquka ezi ndidi zilandelayo:
1. Ionic Liquids
Ulwelo lwe-Ionic lulwelo oluqulunqwe nge-organic cations kunye ne-organic or anorganic anions, ngokuqhelekileyo kunye nokuguquguquka okuphantsi, ukuzinza okuphezulu kwe-thermal kunye nokulungiswa okuphezulu. Olunye ulwelo lwe-ayoni lunokunyibilikisa i-cellulose, kwaye eyona ndlela iphambili kukuqhawula amaqhina e-hydrogen phakathi kwamakhonkco emolekyuli eselulosi. Ulwelo oluqhelekileyo lwe-ionic olunyibilikisa i-cellulose lubandakanya:
I-1-Butyl-3-methylimidazolium chloride ([BMIM]Cl): Olu lwelo lwe-ionic lunyibilikisa i-cellulose ngokusebenzisana neebhondi ze-hydrogen kwi-cellulose ngokusebenzisa abamkeli be-hydrogen bond.
I-1-Ethyl-3-methylimidazolium acetate ([EMIM][Ac]): Olulwelo lwe-ayoni lunokunyibilikisa ugxininiso oluphezulu lweselulosi phantsi kweemeko ezingephi.
2. Isisombululo se-amine oxidant
Isisombululo se-amine oxidant njengesisombululo esixubileyo se-diethylamine (DEA) kunye ne-chloride yobhedu ibizwa ngokuba yi- [Cu (II) -isisombululo se-ammonium], isistim esinamandla sokunyibilikisa esinokunyibilikisa i-cellulose. Itshabalalisa ubume bekristale yeselulosi ngokusebenzisa i-oxidation kunye ne-hydrogen bonding, isenza ikhonkco le-cellulose yemolekyuli ibethambile kwaye inyibilike ngakumbi.
3. Inkqubo yeLithium chloride-dimethylacetamide (LiCl-DMAc).
Inkqubo ye-LiCl-DMAc (i-lithium chloride-dimethylacetamide) yenye yeendlela zakudala zokunyibilikisa i-cellulose. I-LiCl inokwenza ukhuphiswano lweebhondi ze-hydrogen, ngaloo ndlela itshabalalisa inethiwekhi ye-hydrogen bond phakathi kwee-molecule ze-cellulose, ngelixa i-DMAc njenge-solvent inokunxibelelana kakuhle ne-cellulose molecular chain.
4. I-Hydrochloric acid / isisombululo se-zinc chloride
Isisombululo se-hydrochloric acid/zinc chloride sisixhobo esifunyenwe kwangoko esinokunyibilikisa i-cellulose. Iyakwazi ukunyibilikisa i-cellulose ngokwenza i-coordination effect phakathi kwe-zinc chloride kunye ne-cellulose i-molecular chain, kunye ne-hydrochloric acid etshabalalisa i-hydrogen bond phakathi kwee-molecule ze-cellulose. Nangona kunjalo, esi sisombululo siyingozi kakhulu kwisixhobo kwaye silinganiselwe kwizicelo ezisebenzayo.
5. I-Fibrinolytic enzymes
I-Fibrinolytic enzymes (ezifana ne-cellulases) zichitha i-cellulose ngokubangela ukubola kwe-cellulose kwii-oligosaccharides ezincinci kunye ne-monosaccharides. Le ndlela inoluhlu olubanzi lwezicelo kwiinkalo ze-biodegradation kunye nokuguqulwa kwe-biomass, nangona inkqubo yokutshatyalaliswa kwayo ayikona ukuchithwa kweekhemikhali ngokupheleleyo, kodwa ifunyenwe nge-biocatalysis.
(3) Inkqubo yokuchithwa kwe-cellulose
Ii-reagents ezahlukeneyo zineendlela ezahlukeneyo zokunyibilikisa i-cellulose, kodwa ngokubanzi zingabalelwa kwiindlela ezimbini eziphambili:
Ukutshatyalaliswa kweebhondi ze-hydrogen: Ukonakalisa iibhondi ze-hydrogen phakathi kwamatyathanga eemolekyuli ze-cellulose ngokhuphiswano lwe-hydrogen bond okanye ukusebenzisana kwe-ionic, iyenza inyibilike.
Ukuphumla kwe-molecular chain: Ukwandisa ukuthamba kwe-cellulose ye-molecular chain kunye nokunciphisa i-crystallinity yamaketanga eemolekyuli ngeendlela eziphathekayo okanye zekhemikhali, ukwenzela ukuba zinyibilike kwii-solvents.
(4) Ukusetyenziswa okusebenzayo kwe-cellulose dissolution
Ukuchithwa kweCellulose kunezicelo ezibalulekileyo kwiinkalo ezininzi:
Ukulungiswa kwe-cellulose derivatives: Emva kokuchithwa kwe-cellulose, kunokutshintshwa ngakumbi kwimichiza ukuze kulungiswe i-cellulose ethers, i-cellulose esters kunye nezinye izinto eziphuma kuzo, ezisetyenziswa ngokubanzi kukutya, amayeza, iingubo kunye nezinye iindawo.
Izinto ezisekelwe kwi-cellulose: Ukusebenzisa i-cellulose echithiweyo, i-cellulose nanofibers, i-cellulose membranes kunye nezinye izinto zinokulungiswa. Ezi zixhobo zineempawu ezintle zoomatshini kunye ne-biocompatibility.
Amandla e-Biomass: Ngokunyibilikisa kunye nokunciphisa i-cellulose, inokuguqulwa ibe yishukela evuthayo yokuvelisa i-biofuels efana ne-bioethanol, enceda ukufezekisa uphuhliso kunye nokusetyenziswa kwamandla avuselelekayo.
Ukuchithwa kwe-cellulose yinkqubo enzima ebandakanya iikhemikhali ezininzi kunye neendlela zomzimba. Ulwelo lwe-Ionic, izisombululo ze-amino oxidant, iinkqubo ze-LiCl-DMAc, izisombululo ze-hydrochloric acid/zinc chloride kunye ne-cellolytic enzymes okwangoku ziyaziwa njengee-agent ezisebenzayo zokunyibilikisa i-cellulose. I-arhente nganye inendlela yayo eyodwa yokutshatyalaliswa kunye necandelo lesicelo. Ngophononongo olunzulu lwendlela yokuchithwa kwe-cellulose, kukholelwa ukuba iindlela zokuchithwa ezisebenza ngokufanelekileyo kunye nokusingqongileyo ziya kuphuhliswa, zibonelela ngamathuba amaninzi okusetyenziswa kunye nokuphuhliswa kweselulosi.
Ixesha lokuposa: Jul-09-2024