I-Cellulose iyi-polysaccharide eyinkimbinkimbi eyakhiwe amayunithi amaningi e-glucose axhunywe yizibopho ze-β-1,4-glycosidic. Iyingxenye eyinhloko yezindonga zamaseli ezitshalo futhi inikeza izindonga zamaseli ezitshalo ukwesekwa okuqinile kwesakhiwo kanye nokuqina. Ngenxa yeketanga elide lama-molecule e-cellulose kanye ne-crystallinity ephezulu, inokuqina okuqinile kanye nokungancibiliki.
(1) Izakhiwo ze-cellulose kanye nobunzima bokuncibilika
I-Cellulose inezakhiwo ezilandelayo ezenza kube nzima ukuncibilika:
Ukuqina okuphezulu kwekristali: Amaketanga e-cellulose molecular akha isakhiwo se-lattice esiqinile ngokusebenzisa izibopho ze-hydrogen kanye namandla e-van der Waals.
Izinga eliphezulu lokupholisha: Izinga lokupholisha (okungukuthi ubude bochungechunge lwama-molecule) lwe-cellulose liphezulu, ngokuvamile lisukela emakhulwini kuya ezinkulungwaneni zamayunithi e-glucose, okwandisa ukuzinza kwe-molecule.
Inethiwekhi yezibopho ze-hydrogen: Izibopho ze-hydrogen zikhona kabanzi phakathi nangaphakathi kwezintambo zama-molecule e-cellulose, okwenza kube nzima ukubhujiswa nokuncibilikiswa yizinyibilikisi ezijwayelekile.
(2) Ama-reagent ancibilikisa i-cellulose
Njengamanje, ama-reagent aziwayo angancibilikisa i-cellulose ngempumelelo afaka phakathi izigaba ezilandelayo:
1. Uketshezi lwe-Ionic
Ama-ionic liquids ayizinto eziwuketshezi ezakhiwe ngama-organic cations kanye nama-anion angokwemvelo noma angaphili, ngokuvamile anokuguquguquka okuphansi, ukuqina okuphezulu kokushisa kanye nokulungiswa okuphezulu. Amanye ama-ionic liquids angancibilikisa i-cellulose, futhi indlela eyinhloko ukuphula izibopho ze-hydrogen phakathi kwamaketanga e-cellulose molecular. Ama-ionic liquids avamile ancibilikisa i-cellulose afaka:
I-1-Butyl-3-methylimidazolium chloride ([BMIM]Cl): Lolu ketshezi lwe-ionic luncibilikisa i-cellulose ngokusebenzisana nezibopho ze-hydrogen ku-cellulose ngokusebenzisa izamukeli zezibopho ze-hydrogen.
I-1-Ethyl-3-methylimidazolium acetate ([EMIM][Ac]): Lolu ketshezi lwe-ionic lungancibilikisa amazinga aphezulu e-cellulose ngaphansi kwezimo ezithambile.
2. Isixazululo se-amine oxidant
Isixazululo se-amine oxidant njengesixazululo esixubile se-diethylamine (DEA) kanye ne-copper chloride sibizwa ngokuthi [isixazululo se-Cu(II)-ammonium], okuyisistimu eqinile yokunyibilikisa engancibilikisa i-cellulose. Sibhubhisa isakhiwo sekristalu se-cellulose nge-oxidation kanye ne-hydrogen bonding, okwenza uchungechunge lwama-molecule e-cellulose lube mnene futhi luncibilike kakhudlwana.
3. Uhlelo lwe-Lithium chloride-dimethylacetamide (LiCl-DMac)
Uhlelo lwe-LiCl-DMac (i-lithium chloride-dimethylacetamide) lungenye yezindlela zakudala zokuncibilikisa i-cellulose. I-LiCl ingakha umncintiswano wezibopho ze-hydrogen, ngaleyo ndlela ibhubhise inethiwekhi yezibopho ze-hydrogen phakathi kwama-molecule e-cellulose, kuyilapho i-DMac njenge-solvent ingasebenzisana kahle ne-cellulose molecular chain.
4. Isixazululo se-Hydrochloric acid/zinc chloride
Isixazululo se-hydrochloric acid/zinc chloride siyi-reagent etholakale ekuqaleni engancibilikisa i-cellulose. Singancibilikisa i-cellulose ngokwakha umphumela wokuxhumanisa phakathi kwamaketanga e-zinc chloride nama-cellulose molecular, kanye ne-hydrochloric acid ebhubhisa izibopho ze-hydrogen phakathi kwama-molecule e-cellulose. Kodwa-ke, lesi sixazululo singcolisa kakhulu imishini futhi sinqunyelwe ekusetshenzisweni okusebenzayo.
5. Ama-enzyme e-Fibrinolytic
Ama-enzyme e-fibrinolytic (njenge-cellulases) ancibilikisa i-cellulose ngokubangela ukubola kwe-cellulose ibe ama-oligosaccharide amancane nama-monosaccharides. Le ndlela inezindlela eziningi zokusebenzisa emikhakheni yokubola kwe-biogradation kanye nokuguqulwa kwe-biomass, yize inqubo yayo yokuncibilika ingeyona ukuncibilika kwamakhemikhali ngokuphelele, kodwa itholakala nge-biocatalysis.
(3) Indlela yokuncibilika kwe-cellulose
Ama-reagent ahlukene anezindlela ezahlukene zokuncibilikisa i-cellulose, kodwa ngokuvamile angabangelwa izindlela ezimbili eziyinhloko:
Ukubhujiswa kwezibopho ze-hydrogen: Ukubhujiswa kwezibopho ze-hydrogen phakathi kwamaketanga e-cellulose molecular ngokusebenzisa ukwakheka kwezibopho ze-hydrogen ezincintisanayo noma ukusebenzisana kwe-ionic, okwenza kube yinto encibilikayo.
Ukuphumula kweketanga lama-molecule: Ukwandisa ubumnene beketanga lama-molecule e-cellulose nokunciphisa ukwakheka kwe-crystallinity yeketanga lama-molecule ngezindlela zomzimba noma zamakhemikhali, ukuze zincibilike ezinyibilikisini.
(4) Ukusetshenziswa okungokoqobo kokuncibilikiswa kwe-cellulose
Ukuncibilikiswa kwe-cellulose kunezicelo ezibalulekile emikhakheni eminingi:
Ukulungiswa kwe-cellulose derivatives: Ngemva kokuncibilikisa i-cellulose, ingashintshwa ngamakhemikhali ukuze kulungiselelwe i-cellulose ethers, i-cellulose esters kanye nezinye izinto ezisetshenziswa kakhulu ekudleni, emithini, ekumbozeni nakwezinye izindawo.
Izinto ezisekelwe ku-cellulose: Kusetshenziswa i-cellulose encibilikisiwe, kungalungiswa ama-nanofiber e-cellulose, ama-membrane e-cellulose nezinye izinto. Lezi zinto zinezakhiwo ezinhle zemishini kanye nokuhambisana kwezinto eziphilayo.
Amandla e-biomass: Ngokuncibilikisa nokonakalisa i-cellulose, angaguqulwa abe ushukela ovundiswayo ukuze kukhiqizwe amafutha e-biofuel njenge-bioethanol, okusiza ekufezeni ukuthuthukiswa nokusetshenziswa kwamandla avuselelekayo.
Ukuqedwa kwe-cellulose kuyinqubo eyinkimbinkimbi ehilela izindlela eziningi zamakhemikhali nezomzimba. Uketshezi lwe-Ionic, izixazululo ze-amino oxidant, izinhlelo ze-LiCl-DMAc, izixazululo ze-hydrochloric acid/zinc chloride kanye nama-enzyme e-cellolytic okwamanje aziwa njengezinto ezisebenzayo zokuqedwa kwe-cellulose. I-ejenti ngayinye inendlela yayo ehlukile yokuqedwa kanye nensimu yokusebenzisa. Ngocwaningo olujulile lwendlela yokuqedwa kwe-cellulose, kukholelwa ukuthi izindlela zokuqedwa ezisebenza kahle nezinobungani nemvelo zizothuthukiswa, zinikeze amathuba engeziwe okusetshenziswa nokuthuthukiswa kwe-cellulose.
Isikhathi sokuthunyelwe: Julayi-09-2024