Impahla ebaluleke kakhulu yesixazululo se-cellulose ether yimpahla yayo ye-rheological. Izakhiwo ezikhethekile ze-rheological zama-cellulose ethers amaningi azenza zisetshenziswe kabanzi emikhakheni ehlukahlukene, futhi ukutadisha izakhiwo ze-rheological kunenzuzo ekuthuthukiseni izinkambu ezintsha zokufaka isicelo noma ukuthuthukiswa kwezinye izinkambu zohlelo lokusebenza. U-Li Jing wase-Shanghai Jiao Tong University wenze ucwaningo oluhlelekile mayelana nezakhiwo ze-rheologicali-carboxymethylcellulose (CMC), okuhlanganisa nomthelela wamapharamitha wesakhiwo samangqamuzana e-CMC (isisindo samangqamuzana nezinga lokushintsha), ukugxilisa ingqondo kwe-pH, namandla e-ionic. Imiphumela yocwaningo ibonisa ukuthi i-viscosity ye-zero-shear yesisombululo iyanda ngokunyuka kwesisindo samangqamuzana kanye nezinga lokushintshwa. Ukwanda kwesisindo samangqamuzana kusho ukukhula kweketango lamangqamuzana, futhi ukubopha kalula phakathi kwama-molecule kwandisa i-viscosity yesisombululo; izinga elikhulu lokushintshanisa kwenza ama-molecule anwebe kakhulu esixazululo. Isimo sikhona, umthamo we-hydrodynamic mkhulu, futhi i-viscosity iba nkulu. I-viscosity yesisombululo samanzi se-CMC iyanda ngokwanda kokugxila, okune-viscoelasticity. I-viscosity yesisombululo iyancipha ngenani le-pH, futhi lapho iphansi kunenani elithile, i-viscosity iyanda kancane, futhi ekugcineni i-asidi yamahhala yakheka futhi iyancipha. I-CMC iyipolymer ye-polyanionic, lapho ingeza ama-ion kasawoti e-monovalent Na+, K+ isihlangu, i-viscosity izokwehla ngokufanele. Ukwengezwa kwe-divalent cation Caz+ kubangela ukuthi i-viscosity yesisombululo yehle kuqala bese ikhula. Uma ukugxila kwe-Ca2+ kuphakeme kunephuzu le-stoichiometric, ama-molecule e-CMC asebenzisana ne-Ca2+, futhi kukhona isakhiwo esikhulu esikhona esixazululweni. U-Liang Yaqin, waseNyakatho yeNyuvesi yaseChina, njll. wasebenzisa indlela ye-viscometer kanye nendlela ye-viscometer ejikelezayo ukuze enze ucwaningo olukhethekile mayelana nezakhiwo ze-rheological ze-dilute ne-concentrated solutions of modified hydroxyethyl cellulose (CHEC). Imiphumela yocwaningo ithole ukuthi: (1) I-Cationic hydroxyethyl cellulose inokuziphatha okujwayelekile kwe-polyelectrolyte viscosity emanzini ahlanzekile, futhi i-viscosity encishisiwe iyanda ngokunyuka kokugxila. I-viscosity yangaphakathi ye-cationic hydroxyethyl cellulose enezinga eliphezulu lokushintsha inkulu kunaleyo ye-cationic hydroxyethyl cellulose enezinga eliphansi lokushintsha. (2) Isixazululo se-cationic hydroxyethyl cellulose sibonisa izici zoketshezi ezingezona eze-Newtonian futhi sinezici zokunciphisa i-shear: njengoba ukugxila kwesisindo sesixazululo kukhula, i-viscosity yayo ebonakalayo iyakhula; ekuhlanganiseni okuthile kwesisombululo sikasawoti, i-CHEC ebonakalayo i-viscosity Iyancipha ngokunyuka kokugxila kasawoti okungeziwe. Ngaphansi kwesilinganiso sokugunda okufanayo, i-viscosity ebonakalayo ye-CHEC ohlelweni lwesixazululo lwe-CaCl2 iphakeme kakhulu kunaleyo ye-CHEC ohlelweni lwesisombululo se-NaCl.
Ngokujula okuqhubekayo kocwaningo kanye nokwanda okuqhubekayo kwezinkambu zezicelo, izakhiwo zezixazululo zesistimu exubile ezakhiwe ama-ether e-cellulose ahlukene nazo ziye zathola ukunakwa kwabantu. Isibonelo, i-sodium carboxymethyl cellulose (NACMC) kanye ne-hydroxyethyl cellulose (HEC) isetshenziswa njengama-ejenti ahambisa amafutha ezindaweni zamafutha, anezinzuzo zokuphikiswa okuqinile kwe-shear, izinto zokusetshenziswa eziningi kanye nokungcoliswa kwemvelo okuncane, kodwa umphumela wokuzisebenzisa zodwa awulungile. Nakuba okokuqala kune-viscosity enhle, kuthinteka kalula ngokushisa kwe-reservoir kanye nosawoti; nakuba lesi sakamuva sinokushisa okuhle nokumelana nosawoti, ikhono laso lokujiya liphansi futhi isilinganiso sikhulu uma kuqhathaniswa. Abacwaningi baxuba izixazululo ezimbili futhi bathola ukuthi i-viscosity yesisombululo esiyinhlanganisela yaba nkulu, ukumelana nezinga lokushisa nokumelana nosawoti kwathuthukiswa ngezinga elithile, futhi umphumela wokufaka isicelo wathuthukiswa. U-Verica Sovilj et al. baye bafunda ukuziphatha kwe-rheological kwesisombululo sesistimu exubile eyakhiwe yi-HPMC ne-NACMC kanye ne-anionic surfactant ene-viscometer ejikelezayo. Ukuziphatha kwe-rheological kohlelo kuncike ku-HPMC-NACMC, HPMC-SDS kanye ne-NACMC- (HPMC- SDS) imiphumela ehlukene eyenzeka phakathi.
Izakhiwo ze-rheological zezixazululo ze-cellulose ether nazo zithinteka yizici ezihlukahlukene, njengezithasiselo, amandla omshini wangaphandle kanye nokushisa. UTomoaki Hino et al. wafunda umphumela wokwengezwa kwe-nicotine kuzakhiwo ze-rheological ze-hydroxypropyl methylcellulose. Ku-25C kanye nokugxila okungaphansi kuka-3%, i-HPMC ibonise ukuziphatha koketshezi lwe-Newtonian. Lapho i-nicotine yengezwa, i-viscosity yanda, okwakubonisa ukuthi i-nicotine yandisa ukubophaI-HPMCama-molecule. I-Nicotine lapha ibonisa umphumela wosawoti ophakamisa iphuzu lejeli nendawo yenkungu ye-HPMC. Amandla kagesi afana ne-shear force nawo azoba nomthelela othile ezimpahleni ze-cellulose ether solution aqueous. Ukusebenzisa i-rheological turbidimeter kanye nensimbi encane yokusabalalisa ukukhanya kwe-angle, kutholakala ukuthi kusixazululo se-semi-dilute, okwandisa izinga lokugunda, ngenxa yokuxubana kwe-shear, izinga lokushisa lokuguquka kwephuzu lenkungu lizokhula.
Isikhathi sokuthumela: Apr-28-2024