Cellulose ipolysaccharide yakaoma inoumbwa nemayuniti akawanda eglucose akabatana ne β-1,4-glycosidic bonds. Ndiyo chikamu chikuru chemadziro emasero emiti uye inopa madziro emasero emiti rutsigiro rwakasimba rwechimiro uye kusimba. Nekuda kwecheni refu yemasero e cellulose uye crystallinity yakakwira, ine kugadzikana kwakasimba uye kusanyungudika.
(1) Hunhu hwe cellulose uye kuoma kwekunyungudika
Cellulose ine zvinhu zvinotevera zvinoita kuti zviome kunyunguduka:
Kusimba kwakanyanya: Maketani emamorekuru e cellulose anoumba chimiro chakasimba che lattice kuburikidza ne hydrogen bonds uye van der Waals forces.
Dhigirii repamusoro repolymerization: Dhigirii repolymerization (kureva kureba kwecheni yemamorekuru) yecellulose yakakwira, inowanzo tangira pamazana kusvika kuzviuru zvemayuniti eglucose, izvo zvinowedzera kugadzikana kwemorekuru.
Network yehydrogen bond: Hydrogen bonds inowanikwa zvakanyanya pakati uye mukati me cellulose molecular chains, zvichiita kuti zviome kuparadzwa nekunyungudutswa ne general solvents.
(2) Zvinogadzirisa zvinonyungudutsa cellulose
Parizvino, ma reagents anozivikanwa anogona kunyungudutsa cellulose zvinobudirira anosanganisira mapoka anotevera:
1. Mvura yeIonic
Zvinwiwa zveIonic zvinwiwa zvinoumbwa nema organic cations uye maanion eorganic kana inorganic, anowanzova nekushomeka kwakaderera, kugadzikana kwakanyanya kwekupisa uye kugadziriswa kwakanyanya. Mamwe ma ionic liquids anogona kunyungudutsa cellulose, uye nzira huru ndeyekuputsa hydrogen bonds pakati pe cellulose molecular chains. Zvinwiwa zveIonic zvinonyungudutsa cellulose zvinosanganisira:
1-Butyl-3-methylimidazolium chloride ([BMIM]Cl): Ichi chinwiwa cheionic chinonyungudutsa cellulose nekubatana nezvisungo zvehydrogen mu cellulose kuburikidza nezvinogamuchira zvisungo zvehydrogen.
1-Ethyl-3-methylimidazolium acetate ([EMIM][Ac]): Iyi ionic liquid inogona kunyungudutsa huwandu hwakawanda hwe cellulose mumamiriro ezvinhu akapfava.
2. Mhinduro yeAmine oxidant
Mhinduro yeAmine oxidant yakaita semhinduro yakasanganiswa yediethylamine (DEA) necopper chloride inonzi [Cu(II)-ammonium solution], inova sisitimu yakasimba ye solvent inogona kunyungudutsa cellulose. Inoparadza chimiro chekristaro che cellulose kuburikidza ne oxidation ne hydrogen bonding, zvichiita kuti cellulose molecular chain ive yakapfava uye inonyunguduka zvakanyanya.
3. Sisitimu yeLithium chloride-dimethylacetamide (LiCl-DMac)
Sisitimu yeLiCl-DMAc (lithium chloride-dimethylacetamide) ndeimwe yenzira dzekare dzekunyungudutsa cellulose. LiCl inogona kuumba makwikwi ehydrogen bonds, nokudaro ichiparadza network yehydrogen bond pakati pemamorekuru ecellulose, nepo DMAc se solvent ichigona kushanda zvakanaka ne cellulose molecular chain.
4. Hydrochloric acid/zinc chloride solution
Mushonga wehydrochloric acid/zinc chloride imushonga wakawanikwa kare unogona kunyungudutsa cellulose. Unogona kunyungudutsa cellulose nekugadzira coordination effect pakati pezinc chloride ne cellulose molecular chains, uye hydrochloric acid ichiparadza hydrogen bonds pakati pe cellulose molecules. Zvisinei, mushonga uyu unokuvadza zvakanyanya michina uye une mashandisirwo mashoma.
5. Maenzayimu eFibrinolytic
Ma enzyme e fibrinolytic (akadai se cellulases) anonyungudutsa cellulose nekuita kuti cellulose iparare kuita ma oligosaccharides madiki nema monosaccharides. Nzira iyi ine mashandisirwo akasiyana-siyana mu biodegradation uye biomass conversion, kunyangwe nzira yekunyunguduka kwayo isiri chemical dissolve zvachose, asi inoitwa kuburikidza ne biocatalysis.
(3) Maitiro ekunyungudika kweselulosi
Ma reagent akasiyana ane nzira dzakasiyana dzekunyungudutsa cellulose, asi kazhinji anogona kuverengerwa kune nzira mbiri huru:
Kuparadzwa kwezvisungo zvehydrogen: Kuparadza zvisungo zvehydrogen pakati pemaketani emasero e cellulose kuburikidza nekuumbwa kwezvisungo zvehydrogen zvinokwikwidzana kana kuti ionic interaction, zvichiita kuti zvinyunguduke.
Kurerukirwa kwecheni yemamorekuru: Kuwedzera kupfava kwecheni dzemamorekuru dzecellulose uye kuderedza kupenya kwecheni dzemamorekuru kuburikidza nenzira dzemuviri kana dzemakemikari, kuitira kuti dzikwanise kunyungudutswa muzvinonyungudutsa.
(4) Mashandisirwo anoshanda ekubvisa cellulose
Kunyungudika kwesero kune mashandisirwo akakosha muminda yakawanda:
Kugadzirwa kwezvinhu zvinobva mu cellulose: Mushure mekunyungudutsa cellulose, inogona kuchinjwazve nemakemikari kuti igadzire cellulose ethers, cellulose esters nezvimwe zvinobva mu cellulose, izvo zvinoshandiswa zvakanyanya mukudya, mishonga, machira nedzimwe nzvimbo.
Zvinhu zvakagadzirwa ne cellulose: Kushandisa cellulose yakanyungudutswa, cellulose nanofibers, cellulose membranes nezvimwe zvinhu zvinogona kugadzirwa. Zvinhu izvi zvine hunhu hwakanaka hwemakanika uye zvinoenderana nehupenyu.
Simba reBiomass: Nekunyungudutsa nekuderedza cellulose, rinogona kushandurwa kuita shuga dzinoviriswa kuti dzigadzirwe mafuta ebiofuels akadai sebioethanol, iyo inobatsira pakugadzira nekushandisa simba rinogona kuvandudzwa.
Kunyungudika kweseroli inzira yakaoma inosanganisira nzira dzakasiyana-siyana dzemakemikari nemuviri. Zvinwiwa zveIonic, mhinduro dzeamino oxidant, masisitimu eLiCl-DMAc, mhinduro dzehydrochloric acid/zinc chloride uye ma enzymes ecellolytic parizvino anozivikanwa senzira dzinoshanda dzekunyungudika kweseroli. Chinhu chimwe nechimwe chine nzira yaro yekunyungudika uye nzvimbo yekushandisa. Nekudzidza kwakadzama kwenzira yekunyungudika kweseroli, zvinotendwa kuti nzira dzekunyungudika dzinoshanda uye dzakachengeteka dzichagadzirwa, zvichipa mikana yakawanda yekushandisa nekugadzira seroli.
Nguva yekutumira: Chikunguru-09-2024