I-solubility yamanzi ye-ether eguquliwe ye-cellulose ithinteka izinga lokushisa. Ngokuvamile, izitha eziningi ze-cellulose zincibilika emanzini emazingeni okushisa aphansi. Lapho izinga lokushisa likhuphuka, ukubulawa kwabo kuhamba kancane kancane kwaba mpofu futhi ekugcineni kube ukungaboni ngaso linye. Ukushisa okubucayi okubucayi (LCST: Ukushisa okubucayi okubucayi) kuyindlela ebalulekile yepharamitha ebalulekile yokushintsha ukuguqulwa kwe-solubity ye-cellulose ether lapho izinga lokushisa lishintsha, okungukuthi, ngaphezulu kokushisa kwesisombululo esisezingeni eliphansi, okuphezulu kwe-ether kufakwa emanzini.
Ukushisa kwezixazululo ze-methylcellulose kufundisiwe futhi kwachazwa indlela yoshintsho ekuhlanzeni kwe-solubity. Njengoba kushiwo ngenhla, lapho ikhambi le-methylcellose lisemazingeni aphansi, ama-macromolecule azungezwe ama-molecule amanzi ukuze akhe isakhiwo sekheji. Ukushisa okusetshenziselwe ukunyuka kwezinga lokushisa kuzophula isibopho se-hydrogen phakathi kwe-molecule yamanzi kanye ne-molecule ye-MC, i-methyl-fana ne-hydrophobic methyl gein ebonakalayo, kanti i-methyl ye-methyl i-methyl gein ivezwa, okwenza kube khona ukulungiselela nokutadisha I-Hydrophobic Association ye-Hydroxypropylylylylylyllose methylcellulose i-hydrogel. Uma amaqembu we-methyl kumaketanga afanayo amangqamuzana ahlanganiswe nge-hydrophophobile, lokhu kuhlangana kwe-intramolecular kuzokwenza lonke i-molecule livele lahlanganiswa. Kodwa-ke, ukwanda kwezinga lokushisa kuzoqinisa ukunyakaza kwengxenye ye-chain, ukusebenzisana kwe-hydrophobic ku-molecule kuzobe kungazinzile, futhi iketanga lamangqamuzo lizoshintsha kusuka esimweni esihlanganisiwe siye ezweni elihlanganisiwe. Ngalesi sikhathi, ukusebenzisana kwe-hydrophobic phakathi kwama-molecule kuqala ukubusa. Lapho izinga lokushisa likhuphuka kancane kancane, izibopho eziningi ze-hydrogen ziphukile, futhi ama-cellulose ether molecule ahlukaniswe nesakhiwo sekheji, kanye nama-macromolecule asondelene nomunye nomunye ahlangana ngokuhlangana kwe-hydrophobic ukwakha i-hydrophobic. Ngokwenyuka okwengeziwe kwamazinga okushisa, ekugcineni wonke amabhondi e-hydrogen aphukile, futhi inhlangano yayo ye-hydrophobic ifinyelela inani eliphakeme, elikhulisa inombolo nosayizi we-hydrophobic aggregates. Ngale nqubo, i-methylcellulose iyaqhubeka ngokuqhubekayo futhi ekugcineni ekugcineni ingaphansi kwamanzi. Lapho amazinga okushisa enyuka aze afike lapho kwakhiwa khona isakhiwo senethiwekhi enezici ezintathu phakathi kwama-macromolecule, kubonakala sengathi kwakha i-gel macroscopically.
Jun Gao noGeorge Haidar et al batakutfutfutfutfutfutfutfutfutfonta umphumela we-hydroxypropylropylropyllopyllocyllop aquleose khambi lokusakaza lokukhanya, futhi kuhlongotela ukuthi izinga lokushisa lesisusa se-hydroxypropyllos licishe libe ngu-410C. Emazingeni okushisa aphansi kune-390c, uchungechunge olulodwa lwamangqamuzana we-hydroxypropyls lusesimweni esihlanganiswe ngokungahleliwe, futhi ukusatshalaliswa kwe-hydrodynamic radius kwama-molecule kubanzi, futhi akukho hlangene phakathi kwama-macromolecule. Lapho izinga lokushisa lenyuka liye ku-390c, ukusebenzisana kwe-hydrophobic phakathi kwamaketanga amamolekyuli kuba namandla, ama-macromolecule ahlangana, futhi amanzi e-solubility amanzi ampofu. Kodwa-ke, kulokhu kushisa, kuphela ingxenye encane ye-hydroxypropyllopyllopyllopyllosyllose ama-aggreces aqukethe amaketanga ambalwa aqukethe amaketanga ambalwa ama-molecular, kanti iningi lama-molecule asesimweni samaketanga angashadi ahlakazekile. Lapho amazinga okushisa ekhuphuka abe ngu-400C, ama-macromolecule amaningi abamba iqhaza ekwakhekeni kwama-aggregates, futhi i-solubity iba yimbi kakhulu, kepha ngalesi sikhathi, amanye ama-molecule asesimweni samaketanga angashadile. Lapho amazinga okushisa esebangeni lama-410c-440c, ngenxa yethonya elinamandla le-hydrophobic emazingeni okushisa aphezulu, ama-molecule amaningi ahlangana ukuze akhe ama-nanoparticles amakhulu nawomakhemikhali ngokusatshalaliswa okufanayo. Ukuphakama kuba nkulu futhi kube mnene. Ukwakheka kwalezi zinhlanganisela ze-hydrophobic kuholela ekwakhekeni kwezifunda eziphezulu zokuhlushwa kwe-polymer eziphakeme ngesisombululo, okubizwa ngokuthi yi-microscopic Isigaba Sehlukaniso.
Kufanele kuboniswe ukuthi ama-aggregates ama-nanoparticle asesimweni esizinzile se-kinetically, hhayi isimo esizinzile. Lokhu kungenxa yokuthi yize isakhiwo sokuqala sekheji sibhujisiwe, kusekhona isibopho esinamandla se-hydrogen phakathi kwe-hydrophilic hydroxyl gerod kanye ne-molecule yamanzi, evimbela amaqembu we-hydrophobic anjenge-hydrophobic njenge-methyl ne-hydroxyproppy kusuka kuhlanganiswa phakathi. Ama-nanoparticle aggregates afinyelela ekulinganiseni okunamandla nokuzinza ngaphansi kwethonya elihlangene lemiphumela emibili.
Ngaphezu kwalokho, lolu cwaningo luthole nokuthi izinga lokushisa libuye libe nomthelela ekwakhekeni kwezinhlayiya ezihlanganisiwe. Ngezinga elisheshayo lokufudumeza, ukuhlanganiswa kwamaketanga amangqamuzana kushesha, kanti usayizi wama-nanopartics asunguliwe mncane; Futhi lapho izinga lokushisa lihamba kancane, ama-macromolecule anamathuba amaningi okwenza ama-aggregate akhulu ama-nanoparticle asayizi.
Isikhathi Sokuthumela: APR-17-2023