Ukulungiselelai-ultrafine yomhlaba engajwayelekile
Izinhlanganisela zomhlaba ezingavamile ze-Ultrafine zinezinhlobonhlobo zokusetshenziswa uma kuqhathaniswa nezinhlanganisela zomhlaba ezingavamile ezinosayizi bezinhlayiyana ezivamile, futhi okwamanje kunocwaningo olwengeziwe ngazo. Izindlela zokulungiselela zihlukaniswe ngendlela yesigaba esiqinile, indlela yesigaba soketshezi, nendlela yesigaba segesi ngokuya ngesimo sokuhlanganisa sento. Njengamanje, indlela yesigaba se-liquid isetshenziswa kabanzi kuma-laboratories nasezimbonini ukulungisa izimpushana ze-ultrafine zezinhlanganisela zomhlaba ezingavamile. Ikakhulukazi ihlanganisa indlela yemvula, indlela ye-sol gel, indlela ye-hydrothermal, indlela yesifanekiso, indlela ye-microemulsion kanye nendlela ye-alkyd hydrolysis, phakathi kwayo indlela yemvula ifaneleka kakhulu ukukhiqizwa kwezimboni.
Indlela yemvula iwukwengeza umkhithi esixazululo sikasawoti wensimbi ukuze kunemvula, bese uhlunga, ugeze, wome futhi ubole ukushisa ukuze uthole imikhiqizo yempushana. Ihlanganisa indlela yemvula eqondile, indlela yemvula efanayo kanye nendlela yokwehlisa imvula. Ngendlela evamile yemvula, ama-oxide omhlaba angavamile kanye nosawoti womhlaba ongavamile oqukethe ama-radicals e-asidi aguquguqukayo angatholakala ngokushisa imvula, ngosayizi wezinhlayiyana ezingu-3-5 μ m. Indawo ethile ingaphansi kuka-10 ㎡/g futhi ayinazo izakhiwo ezikhethekile zomzimba namakhemikhali. Indlela ye-ammonium carbonate precipitation method kanye ne-oxalic acid precipitation method okwamanje iyindlela esetshenziswa kakhulu ukukhiqiza izimpushana ze-oxide ezejwayelekile, futhi inqobo nje uma izimo zenqubo yendlela yokuna kwemvula zishintshile, zingasetshenziswa ukulungisa izimpushana ze-ultrafine ezingavamile zomhlaba ze-oxide.
Ucwaningo luye lwabonisa ukuthi izici eziyinhloko ezithinta usayizi wezinhlayiya kanye nokuma kwezinhlayiyana zezimpushana ze-ultrafine zomhlaba ezingavamile endleleni ye-ammonium bicarbonate precipitation zihlanganisa ukugcwala komhlaba ongavamile esixazululweni, izinga lokushisa lemvula, ukugxiliswa kwe-ejenti yemvula, njll. Ukuhlangana komhlaba ongavamile endaweni isisombululo siyisihluthulelo sokwenza izimpushana ze-ultrafine ezihlakazeke ngokufanayo. Isibonelo, ekuhlolweni kwe-Y3+ kwezulu ukuze kulungiswe i-Y2O3, lapho ukugcwala komhlaba okungavamile kungu-20~30g/L (kubalwa yi-Y2O3), inqubo yemvula ibushelelezi, kanye ne-yttrium oxide ultrafine powder etholwe emvuleni ye-carbonate ukomisa nokushiswa kuncane, okufanayo, futhi Ukuhlakazeka kuhle.
Ekuphenduleni kwamakhemikhali, izinga lokushisa liyisici esinqumayo. Ezivivinyweni ezingenhla, lapho izinga lokushisa lingu-60-70 ℃, imvula ihamba kancane, ukuhlunga kuyashesha, izinhlayiya zixega futhi zifana, futhi ngokuyisisekelo ziyindilinga; Uma izinga lokushisa lokusabela lingaphansi kuka-50 ℃, imvula yakheka ngokushesha, nezinhlamvu eziningi kanye nosayizi bezinhlayiyana ezincane. Ngesikhathi sokusabela, inani lokuchichima kwe-CO2 ne-NH3 lincane, futhi imvula isesimweni esinamathelayo, esingafanele ukuhlungwa nokuwashwa. Ngemva kokushiswa ku-yttrium oxide, kusekhona izinto ezi-blocky ezihlanganisana ngokujulile futhi zibe nobukhulu bezinhlayiyana ezinkulu. Ukugcwala kwe-ammonium bicarbonate nakho kuthinta usayizi wezinhlayiyana ze-yttrium oxide. Lapho ukuhlushwa kwe-ammonium bicarbonate kungaphansi kwe-1mol/L, usayizi wezinhlayiyana ze-yttrium oxide otholiwe mncane futhi umfaniswano; Uma ukugcwala kwe-ammonium bicarbonate kudlula 1mol/L, imvula yendawo izokwenzeka, okubangele ukuhlangana nezinhlayiyana ezinkulu. Ngaphansi kwezimo ezifanele, usayizi wezinhlayiyana we-0.01-0.5 ungatholakala μ M ultrafine yttrium oxide powder.
Endleleni ye-oxalate precipitation, isixazululo se-oxalic acid siyengezwa ngendlela ephansi kuyilapho i-ammonia yengezwa ukuze kuqinisekiswe inani le-pH eliqhubekayo phakathi nenqubo yokusabela, okuholela kusayizi wezinhlayiyana ezingaphansi kuka-1 μ M we-yttrium oxide powder. Okokuqala, lungisa isisombululo se-yttrium nitrate ngamanzi ammonia ukuze uthole i-yttrium hydroxide colloid, bese uyiguqula ngesisombululo se-oxalic acid ukuze uthole usayizi wezinhlayiyana ezingaphansi kwe-1 μ Y2O3 powder of m. Engeza i-EDTA kusisombululo se-Y3+ se-yttrium nitrate ene-concentration of 0.25-0.5mol/L, lungisa i-pH ibe ngu-9 ngamanzi e-ammonia, engeza i-ammonium oxalate, bese uconsa isixazululo esingu-3mol/L HNO3 ngesilinganiso esingu-1-8mL/ iminithi ku-50 ℃ kuze kube yilapho imvula isiqedile ku-pH=2. I-Yttrium oxide powder enosayizi wezinhlayiyana we-40-100nm ingatholakala.
Phakathi nenqubo yokulungiselelai-ultrafine yomhlaba engajwayelekilengendlela yemvula, amazinga ahlukene e-agglomeration ajwayele ukwenzeka. Ngakho-ke, ngesikhathi senqubo yokulungiselela, kuyadingeka ukulawula ngokuqinile izimo zokuhlanganiswa, ngokulungisa inani le-pH, usebenzisa ama-precipitants ahlukene, ukwengeza ama-dispersants, nezinye izindlela zokuhlakaza ngokugcwele imikhiqizo ephakathi. Bese, izindlela zokomisa ezifanele ziyakhethwa, bese ekugcineni, izimpushana ze-ultrafine ezihlakazeke kahle zitholakala ngokubala.
Isikhathi sokuthumela: Apr-21-2023