Ukugcinwa kwamanzi kuyimpahla ebalulekile ezimbonini eziningi ezisebenzisa izinto ze-hydrophilic ezifana ne-cellulose ethers. IHydroxypropylmethylcellulose (HPMC) ingenye ye-cellulose ethers enezakhiwo eziphezulu zokugcina amanzi. I-HPMC i-semi-synthetic polymer etholakala ku-cellulose futhi ivamise ukusetshenziswa ezinhlotsheni zezicelo ezimbonini zokwakha, ezemithi nezokudla.
I-HPMC isetshenziswa kakhulu njenge-thickener, stabilizer kanye ne-emulsifier emikhiqizweni ehlukahlukene yokudla efana no-ayisikhilimu, amasoso kanye nezingubo zokugqoka ukuze kuthuthukiswe ukuthungwa kwazo, ukungaguquguquki nempilo yeshelufu. I-HPMC iphinde isetshenziswe ekukhiqizeni imithi embonini yezemithi njenge-binder, disintegrant kanye ne-ejenti yokuhlanganisa ifilimu. Ibuye isetshenziswe njenge-ejenti yokugcina amanzi ezintweni zokwakha, ikakhulukazi kusimende nodaka.
Ukugcina amanzi kuyisici esibalulekile ekwakhiweni ngoba kusiza ukuthi usimende osanda kuxutshwa nodaka ungabomi. Ukomisa kungabangela ukuncipha nokuqhekeka, okuholela ezinhlakeni ezibuthakathaka nezingazinzile. I-HPMC isiza ukugcina okuqukethwe kwamanzi kusimende nodaka ngokumunca ama-molecule amanzi futhi iwakhulule kancane ngokuhamba kwesikhathi, okuvumela izinto zokwakha ukuthi zelaphe kahle futhi ziqine.
Umgomo wokugcina amanzi we-HPMC usekelwe ku-hydrophilicity yayo. Ngenxa yokuba khona kwamaqembu e-hydroxyl (-OH) esakhiweni sawo samangqamuzana, i-HPMC inokuhlobana okuphezulu kwamanzi. Amaqembu e-hydroxyl asebenzisana nama-molecule amanzi ukuze akhe amabhondi e-hydrogen, okuholela ekwakhekeni kwegobolondo le-hydration elizungeze amaketanga e-polymer. Igobolondo le-hydrated livumela amaketanga e-polymer ukuthi ande, akhulise ivolumu ye-HPMC.
Ukuvuvukala kwe-HPMC kuyinqubo eguquguqukayo encike ezintweni ezahlukahlukene ezifana ne-degree of substitution (DS), usayizi wezinhlayiyana, izinga lokushisa kanye ne-pH. Izinga lokushintsha lisho inani lamaqembu e-hydroxyl afakwe esikhundleni ngeyunithi ngayinye ye-anhydroglucose kuketango le-cellulose. Lapho inani le-DS liphakeme, i-hydrophilicity iyanda futhi kuba ngcono nokusebenza kokugcinwa kwamanzi. Usayizi wezinhlayiyana ze-HPMC uphinda uthinte ukugcinwa kwamanzi, njengoba izinhlayiya ezincane zinendawo enkulu kakhulu ngeyunithi yesisindo, okuholela ekumunceni okukhulu kwamanzi. Izinga lokushisa kanye nenani le-pH lithinta izinga lokuvuvukala nokugcinwa kwamanzi, futhi izinga lokushisa eliphakeme kanye nenani le-pH eliphansi lithuthukisa izici zokuvuvuka nokugcinwa kwamanzi ze-HPMC.
Indlela yokugcina amanzi ye-HPMC ibandakanya izinqubo ezimbili: ukumuncwa kanye nokuwakhipha. Ngesikhathi sokumuncwa, i-HPMC idonsa ama-molecule amanzi endaweni ezungezile, yakhe igobolondo le-hydration elizungeze amaketanga e-polymer. Igobolondo le-hydration livimbela amaketanga e-polymer ukuthi angawi futhi liwagcine ehlukene, okuholela ekuvuvukeni kwe-HPMC. Ama-molecule amanzi amuncwa akha amabhondi e-hydrogen namaqembu e-hydroxyl ku-HPMC, athuthukisa ukusebenza kokugcinwa kwamanzi.
Phakathi ne-desorption, i-HPMC ikhipha kancane ama-molecule amanzi, okuvumela okokwakha ukuthi zelaphe kahle. Ukukhululwa kancane kwama-molecule amanzi kuqinisekisa ukuthi usimende nodaka kuhlala kugcwele amanzi, okuholela esakhiweni esizinzile nesiqinile. Ukukhululwa kancane kwama-molecule amanzi futhi kunikeza amanzi njalo kusimende nodaka, okuthuthukisa inqubo yokwelapha futhi kwandise amandla nokuzinza komkhiqizo wokugcina.
Kafushane, ukugcinwa kwamanzi kuyimpahla ebalulekile ezimbonini eziningi ezisebenzisa izinto ze-hydrophilic ezifana ne-cellulose ethers. I-HPMC ingenye ye-cellulose ethers enezindawo zokugcina amanzi aphezulu futhi isetshenziswa kakhulu embonini yokwakha, ekhemisi neyokudla. Izakhiwo zokugcina amanzi ze-HPMC zisekelwe ku-hydrophilicity yayo, eyenza ikwazi ukumunca ama-molecule amanzi endaweni ezungezile, yakhe igobolondo le-hydration elizungeze amaketanga e-polymer. Igobolondo le-hydrated libangela ukuthi i-HPMC ikhukhumale, futhi ukukhishwa kancane kancane kwama-molecule amanzi kuqinisekisa ukuthi impahla yokwakha ihlala inamanzi ngokugcwele, okuholela esakhiweni esizinzile nesiqinile.
Isikhathi sokuthumela: Aug-24-2023