Cellulose, iyo polymer yeorganic yakawanda kwazvo pasi pano, inoumba chikamu chikuru chebiomass nezvimwe zvinhu zvemaindasitiri. Kusimba kwayo kunoshamisa kwechimiro kunokonzeresa matambudziko ekuparara kwayo zvakanaka, zvakakosha pakushandiswa kwakadai sekugadzira biofuel uye kutonga marara. Hydrogen peroxide (H2O2) yave mukana wekunyungudika kwecellulose nekuda kwehunhu hwayo husina njodzi kunharaunda uye hunhu hwayo hwekuoxidation.
Nhanganyaya:
Cellulose, polysaccharide inoumbwa nemayuniti eglucose akabatana ne β-1,4-glycosidic bonds, chinhu chikuru chiri muchimiro chemadziro emasero emiti. Kuwanda kwayo mu biomass kunoita kuti ive chinhu chinokwezva maindasitiri akasiyana-siyana, anosanganisira mapepa ne pulp, machira, uye bioenergy. Zvisinei, network yakasimba ye hydrogen bonding iri mukati me cellulose fibrils inoita kuti isanyungudike mu solvents dzakawanda, zvichikonzera matambudziko ekushandiswa kwayo nemazvo uye kudzokorodza.
Nzira dzechinyakare dzekunyungudutsa cellulose dzinosanganisira mamiriro akaomarara, akadai semaacid akaomeswa kana ionic liquids, ayo anowanzo batanidzwa nezvinetso zvakatipoteredza uye kushandiswa kwesimba rakawanda. Kusiyana neizvi, hydrogen peroxide inopa imwe nzira inovimbisa nekuda kwehunhu hwayo hwekunyungudutsa zvinyoro nyoro uye mukana wekugadzirisa cellulose isingakuvadzi zvakatipoteredza. Pepa iri rinoongorora nzira dziri pasi pekunyunguduka kwe hydrogen peroxide-mediated cellulose uye rinoongorora kushanda kwayo uye mashandisirwo ayo anoshanda.
Maitiro eKunyungudika kweCellulose neHydrogen Peroxide:
Kunyungudika kwecellulose nehydrogen peroxide kunosanganisira maitiro akaomarara emakemikari, kunyanya kupatsanurwa kweglycosidic bonds uye kukanganiswa kweintermolecular hydrogen bonding. Maitiro acho anowanzo enderera mberi nematanho anotevera:
Kuoxidation kweHydroxyl Groups: Hydrogen peroxide inoita mubatanidzwa ne cellulose hydroxyl groups, zvichikonzera kuumbwa kwehydroxyl radicals (•OH) kuburikidza neFenton kana Fenton-like reactions kana paine transition metal ions. Aya ma radicals anorwisa glycosidic bonds, zvichitanga chain scassion uye kugadzira shorter cellulose fragments.
Kukanganiswa kweHydrogen Bonding: Hydroxyl radicals inokanganisawo network yehydrogen bonding pakati pemaketani ecellulose, zvichiita kuti chimiro chose chisashande zvakanaka uye zvichiita kuti kugadziriswa kugadzikane.
Kugadzirwa kweZvinhu Zvinonyunguduka: Kuora kwemasero eropa kunoguma nekuumbwa kwezvinhu zvinonyunguduka mumvura, zvakaita secarboxylic acids, aldehydes, uye ketones. Izvi zvinobatsira mukunyunguduka kwemasero nekuwedzera kunyunguduka kwemasero uye kuderedza viscosity.
Kubvisa polymerization uye Kupatsanurana: Kuwedzeredza oxidation uye cleavage reactions kunotungamira ku depolymerization ye cellulose chains kuita ma shorter oligomers uye pakupedzisira ku soluble sugars kana zvimwe zvigadzirwa zvine low-molecular-weight.
Zvinhu Zvinokanganisa Kunyungudika kweHydrogen Peroxide-Mediated Cellulose:
Kubudirira kwekunyungudutswa kwe cellulose uchishandisa hydrogen peroxide kunokonzerwa nezvinhu zvakasiyana-siyana, zvinosanganisira:
Kuwanda kweHydrogen Peroxide: Kuwanda kwehydrogen peroxide kunowanzo kukonzera kukurumidza kwekuita kwemasero eropa uye kupera kwemasero eropa zvakanyanya. Zvisinei, kuwanda kwakanyanya kunogona kukonzera kusawirirana kana zvimwe zvinhu zvisingadiwe.
pH neTembiricha: pH yereaction medium inokanganisa kugadzirwa kwehydroxyl radicals uye kugadzikana kwe cellulose derivatives. Mamiriro eacidic ari pakati nepakati (pH 3-5) anowanzo shandiswa kuwedzera kunyungudika kwe cellulose pasina kuora kwakanyanya. Pamusoro pezvo, tembiricha inokanganisa reaction kinetics, tembiricha yakakwira inowanzo kurumidzisa maitiro ekunyungudika.
Kuvapo kweCatalysts: Maion esimbi anoshanduka, akadai sesimbi kana mhangura, anogona kukonzera kuora kwehydrogen peroxide uye kuwedzera kuumbwa kwehydroxyl radicals. Zvisinei, sarudzo yecatalyst uye huwandu hwayo inofanira kugadziriswa nokungwarira kuderedza mhedzisiro uye kuve nechokwadi chekuti chigadzirwa chakanaka.
Kuwanikwa kweCellulose uye Crystallinity: Kuwanikwa kwecellulose cheni kune hydrogen peroxide uye hydroxyl radicals kunokonzerwa nechimiro chezvinhu uye chimiro checrystalline. Nzvimbo dzisina chimiro dzinonyanya kukuvadzwa kupfuura nzvimbo dzine crystalline yakawanda, zvichiita kuti pave nehurongwa hwekurapa kana kugadzirisa zvinhu kuti zvikwanise kushandiswa.
Zvakanakira uye Mashandisirwo eHydrogen Peroxide muCellulose Dissolution:
Hydrogen peroxide ine zvakanakira zvakawanda zvekunyungudika kweselulosi zvichienzaniswa nenzira dzechinyakare:
Kuenderana Kwenzvimbo: Kusiyana nemakemikari akaomarara akadai sesulfuric acid kana chlorinated solvents, hydrogen peroxide haina njodzi uye inoora kuita mvura neokisijeni kana mamiriro ekunze asina kusimba. Hunhu uhwu husingakuvadzi nharaunda hunoita kuti ive yakakodzera kugadziriswa kwecellulose kwenguva refu uye kugadziriswa kwemarara.
Mamiriro Ekuita Zvishoma: Kunyungudika kweselulosi kunosanganisirwa nehydrogen peroxide kunogona kuitwa mumamiriro ekunze ekupisa nekumanikidzwa, zvichideredza kushandiswa kwesimba uye mari yekushandisa zvichienzaniswa nekurapa kweacid hydrolysis kana ionic liquid.
Kupatsanurwa kwemasero: Kupatsanurwa kwemasero eglycosidic bonds nehydrogen peroxide kunogona kudzorwa kusvika pamwero wakati, zvichibvumira shanduko yemhando ye cellulose chains uye kugadzirwa kwezvinhu zvakagadzirwa zvinoenderana nezvinodiwa zvine hunhu hwakasiyana.
Mashandisirwo Azvo Anoshandiswa Pakuchinja-chinja: Zvinhu zvinonyunguduka zve cellulose zvinobva mu hydrogen peroxide zvinogona kushandiswa muzvikamu zvakasiyana-siyana, zvinosanganisira kugadzirwa kwe biofuel, zvinhu zvinoshanda, zvishandiso zve biomedical, uye kurapwa kwemvura yakasviba.
Matambudziko uye Nzira dzeRamangwana:
Pasinei nezvakanaka zvayo, hydrogen peroxide-mediated cellulose dissolving inosangana nematambudziko akawanda nenzvimbo dzinoda kugadziriswa:
Kusarudza uye Goho: Kuwana goho guru rezvinhu zvinonyungudika mu cellulose zvisina kukanganiswa zvakanyanya kuchiri dambudziko, kunyanya kune zvinhu zvakaoma zve biomass zvine lignin ne hemicellulose.
Kuwedzerwa Kwesimba uye Kubatanidzwa Kwemaitiro: Kukwidziridza maitiro ekunyungudutsa cellulose akavakirwa pahydrogen peroxide kusvika padanho remaindasitiri kunoda kunyatsofungisisa nezvekugadzirwa kwema reactor, kudzoreredza solvent, uye matanho ekugadzirisa zvinhu kuti pave nechokwadi chekuti hupfumi hwagara huripo uye kuti nharaunda igare kwenguva refu.
Kugadzirwa kweCatalyst: Kugadzirwa kwe catalyst dzinoshanda dze hydrogen peroxide activation uye cellulose oxidation kwakakosha pakuwedzera reaction rates uye selectivity ukuwo kuchideredza catalyst loading uye by-product formation.
Kusimbisa Zvigadzirwa Zvishoma: Nzira dzekusimbisa zvinhu zvishoma zvinogadzirwa panguva yekunyungudika kweselulosi inosanganiswa nehydrogen peroxide, senge carboxylic acids kana oligomeric shuga, dzinogona kuwedzera kusimba kwese uye kushanda zvakanaka kwehupfumi hwemaitiro acho.
Hydrogen peroxide ine vimbiso yakakura semusanganiswa wegirini uye unochinjika mukunyungudika kwecellulose, ichipa zvakanakira zvakaita sekuenderana kwezvakatipoteredza, mamiriro ekuita zvinyoro nyoro, uye oxidation yakasarudzwa. Pasinei nematambudziko aripo, kuedza kuenderera mberi kwekutsvaga kwakanangana nekujekesa mashandiro aripo, kugadzirisa maparamita ekuita, uye kuongorora mashandisirwo matsva kuchawedzera kugona uye kugarika kwemaitiro akavakirwa pahydrogen peroxide ekuwedzera kunaka kwecellulose.
Nguva yekutumira: Kubvumbi-10-2024