Cellulose ndi polysaccharide yovuta yopangidwa ndi mayunitsi ambiri a shuga olumikizidwa ndi β-1,4-glycosidic bond. Ndilo gawo lalikulu la makoma a maselo a zomera ndipo limapereka makoma a maselo a zomera amphamvu komanso olimba. Chifukwa chautali wa cellulose maselo unyolo ndi mkulu crystallinity, ali amphamvu bata ndi insolubleness.
(1) Makhalidwe a cellulose ndizovuta pakutha
Cellulose ili ndi zinthu zotsatirazi zomwe zimapangitsa kuti zikhale zovuta kusungunuka:
Kuwala kwambiri: Unyolo wa cellulose wa molekyulu umapanga mawonekedwe olimba a lattice kudzera mu ma hydrogen bond ndi mphamvu za van der Waals.
High degree of polymerization: Mlingo wa polymerization (ie kutalika kwa unyolo wa maselo) wa cellulose ndi wokwera, nthawi zambiri umachokera ku mazana mpaka masauzande a mayunitsi a shuga, zomwe zimawonjezera kukhazikika kwa molekyulu.
Ma hydrogen bond network: Ma hydrogen bond amapezeka kwambiri pakati ndi mkati mwa ma cellulose ma cellulose, zomwe zimapangitsa kuti zikhale zovuta kuwonongedwa ndi kusungunuka ndi zosungunulira wamba.
(2) Ma reagents omwe amasungunula mapadi
Pakadali pano, ma reagents odziwika omwe amatha kusungunula cellulose makamaka amaphatikiza magulu awa:
1. Ionic Zamadzimadzi
Zamadzimadzi za Ionic ndi zakumwa zopangidwa ndi organic cations ndi organic kapena inorganic anions, nthawi zambiri zimakhala zotsika kwambiri, kukhazikika kwamafuta komanso kusinthasintha kwakukulu. Zakumwa zina za ayoni zimatha kusungunula mapadi, ndipo njira yayikulu ndikuthyola zomangira za haidrojeni pakati pa maunyolo a cellulose. Zamadzimadzi zomwe zimasungunula cellulose ndi awa:
1-Butyl-3-methylimidazolium chloride ([BMIM]Cl): Madzi a ionic awa amasungunula cellulose polumikizana ndi ma hydrogen bond mu cellulose kudzera mwa olandila ma hydrogen bond.
1-Ethyl-3-methylimidazolium acetate ([EMIM][Ac]): Madzi a ayoni amatha kusungunula kuchuluka kwa cellulose pansi pamikhalidwe yofatsa.
2. Amine okosijeni njira
Amine oxidant solution monga njira yosakanikirana ya diethylamine (DEA) ndi copper chloride imatchedwa [Cu(II) -ammonium solution], yomwe ndi njira yamphamvu yosungunulira yomwe imatha kusungunula cellulose. Imawononga kapangidwe ka kristalo ka cellulose kudzera mu oxidation ndi hydrogen bonding, kupangitsa kuti cellulose cell chain kukhala yofewa komanso kusungunuka kwambiri.
3. Lithium chloride-dimethylacetamide (LiCl-DMAC) dongosolo
Dongosolo la LiCl-DMAc (lithium chloride-dimethylacetamide) ndi imodzi mwa njira zapamwamba zosungunulira cellulose. LiCl imatha kupanga mpikisano wama hydrogen bond, potero imawononga maukonde a haidrojeni pakati pa ma cellulose, pomwe DMAc ngati chosungunulira imatha kulumikizana bwino ndi unyolo wa cellulose.
4. Hydrochloric acid / zinki kolorayidi yankho
Njira ya hydrochloric acid/zinc chloride ndiyo njira yotulukira msanga yomwe imatha kusungunula mapadi. Ikhoza kusungunula mapadi popanga mgwirizano pakati pa zinc koloide ndi mapadi unyolo wa cellulose, ndi hydrochloric acid kuwononga zomangira za haidrojeni pakati pa ma cellulose. Komabe, yankho ili limawononga kwambiri zida ndipo lili ndi malire pazogwiritsa ntchito.
5. Fibrinolytic michere
Ma enzymes a fibrinolytic (monga ma cellulase) amasungunula mapadi poyambitsa kuwonongeka kwa cellulose kukhala oligosaccharides ang'onoang'ono ndi ma monosaccharides. Njirayi ili ndi ntchito zambiri m'magawo a biodegradation ndi kutembenuka kwa biomass, ngakhale kuti kusungunuka kwake sikumasungunuka kwathunthu kwa mankhwala, koma kumatheka kudzera mu biocatalysis.
(3) Njira yothetsera ma cellulose
Ma reagents osiyanasiyana ali ndi njira zosiyanasiyana zosungunulira cellulose, koma nthawi zambiri amatha kutengera njira ziwiri zazikulu:
Kuwonongeka kwa ma hydrogen bond: Kuwononga zomangira za haidrojeni pakati pa maunyolo a cellulose a cellulose kudzera mumpikisano wama hydrogen bond kapena ma ionic, ndikupangitsa kuti sungunuka.
Kupumula kwa unyolo wa mamolekyulu: Kuchulukitsa kufewa kwa maunyolo a cellulose ndikuchepetsa kung'ambika kwa unyolo wa maselo kudzera munjira zakuthupi kapena zamankhwala, kuti athe kusungunuka mu zosungunulira.
(4) Kugwiritsa ntchito kothandiza kwa kusungunuka kwa cellulose
Kusungunuka kwa cellulose kuli ndi ntchito zofunika m'magawo ambiri:
Kukonzekera zotumphukira mapadi: Pambuyo Kutha mapadi, akhoza zina mankhwala kusinthidwa kukonzekera mapadi ethers, mapadi esters ndi zina zotumphukira, amene ankagwiritsa ntchito mu chakudya, mankhwala, zokutira ndi zina.
Zipangizo zopangira ma cellulose: Kugwiritsa ntchito mapadi osungunuka, ma cellulose nanofibers, cellulose nembanemba ndi zinthu zina zitha kukonzedwa. Zidazi zimakhala ndi makina abwino komanso biocompatibility.
Mphamvu ya biomass: Pakusungunula ndi kuwononga mapadi, imatha kusinthidwa kukhala shuga wonyezimira kuti apange ma biofuel monga bioethanol, zomwe zimathandiza kukwaniritsa chitukuko ndi kugwiritsa ntchito mphamvu zongowonjezwdwa.
Kusungunuka kwa ma cellulose ndi njira yovuta yomwe imaphatikizapo njira zambiri za mankhwala ndi zakuthupi. Zamadzimadzi za ionic, amino oxidant solutions, LiCl-DMAc systems, hydrochloric acid/zinc chloride solutions ndi ma cellolytic enzyme pakali pano amadziwika kuti ndi othandiza pakusungunula mapadi. Wothandizira aliyense ali ndi njira yakeyake yosungunula komanso gawo logwiritsira ntchito. Ndi kafukufuku wozama wa makina osungunuka a cellulose, akukhulupirira kuti njira zowonjezera komanso zowononga zachilengedwe zidzapangidwa, zomwe zimapereka mwayi wogwiritsa ntchito komanso kupanga mapangidwe a cellulose.
Nthawi yotumiza: Jul-09-2024