Mubikorwa nubuzima, silika gel irashobora gukoreshwa mukumisha N2, umwuka, hydrogène, gaze naturel [1] nibindi. Ukurikije aside na alkali, desiccant irashobora kugabanywamo ibice: desiccant acide, desalcant ya alkaline na desiccant idafite aho ibogamiye [2]. Gelika ya Silica isa nkaho yumye idafite aho ibogamiye isa nkaho yumye NH3, HCl, SO2, nibindi. n'ubuso bukungahaye mu matsinda ya hydroxyl (reba Ishusho 1). Impamvu geli ya silika ishobora gukuramo amazi nuko itsinda rya hydroxyl ya silicon hejuru ya gelika ya silika rishobora gukora hydrogène ya hydrogène intermolecular hamwe na molekile zamazi, bityo irashobora gukurura amazi bityo ikagira uruhare rwo gukama. Gel ya silika ihindura ibara irimo ion ya cobalt, hanyuma amazi ya adsorption ageze ku kwiyuzuzamo, ion ya cobalt muri gelika ihindura amabara ya silika ihinduka hydrata cobalt ion, kuburyo gel silika yubururu ihinduka umutuku. Nyuma yo gushyushya gel ya silika yijimye kuri 200 ℃ mugihe runaka, isano ya hydrogène hagati ya silika gel na molekile yamazi iracika, hanyuma gelika ya silika ifite ibara ryongeye guhinduka ubururu, kugirango igishushanyo mbonera cya acide silicike na gelika silika irashobora kongera gukoreshwa nkuko bigaragara ku gishushanyo cya 1. Rero, kubera ko ubuso bwa silika gel bukungahaye mumatsinda ya hydroxyl, ubuso bwa silika gel burashobora kandi gukora imigozi ya hydrogène intermolecular ihuza NH3 na HCl, nibindi, kandi ntaburyo bwo gukora nka desiccant ya NH3 na HCl, kandi nta raporo ifatika mubitabo bihari. None ibisubizo ni ibihe? Iyi ngingo yakoze ubushakashatsi bwubushakashatsi bukurikira.
FIG. 1 Igishushanyo mbonera cya acide ortho-silicic na gelika silika
Igice cy'igeragezwa
2.1 Gucukumbura aho ikoreshwa rya silika gel desiccant - Amoniya Ubwa mbere, gelika ya silika ifite ibara ryashyizwe mumazi yatoboye hamwe n'amazi ya amoniya yibanze. Silika ifite ibara ryahindutse ibara ryijimye mumazi yatoboye; Muri ammonia yibanze, silicone ihindura ibara ibanza guhinduka umutuku igahinduka ubururu bworoheje. Ibi byerekana ko gelika silika ishobora gukuramo NH3 cyangwa NH3 · H2 O muri ammonia. Nkuko bigaragara ku gishushanyo cya 2, hydroxide ya calcium ikomeye na ammonium chloride ivanze neza kandi igashyuha mu cyuma cyipimisha. Gazi yavuyemo ikurwaho na alkali lime hanyuma na silika gel. Ibara rya gelika ya silika hafi yicyerekezo cyinjira ryoroha (ibara ryurwego rushyirwa mubikorwa bya silika gel desiccant ku gishushanyo cya 2 harasuzumwa - ammonia 73, icyiciro cya 8 cya 2023 ahanini ni kimwe nibara rya gelika ya silika yatose mumazi yibanze ya ammonia), kandi urupapuro rwipimisha pH ntiruhinduka rugaragara. Ibi byerekana ko NH3 yakozwe itageze ku mpapuro zipimisha pH, kandi yaramamajwe rwose. Nyuma yigihe runaka, hagarika ubushyuhe, fata igice gito cyumupira wa silika gel, ubishyire mumazi yatoboye, ongeramo fenolphthaleine mumazi, igisubizo gihinduka umutuku, byerekana ko gel silika ifite ingaruka zikomeye za adsorption kuri NH3, nyuma yuko amazi yatoboye yoherejwe, NH3 yinjira mumazi yatoboye, igisubizo ni alkaline. Kubwibyo, kubera ko silika gel ifite adsorption ikomeye kuri NH3, ibikoresho byo kumisha silicone ntibishobora gukama NH3.
FIG. 2 Ubushakashatsi bwurwego rwo gukoresha silika gel desiccant - ammonia
2 Icyitegererezo kimaze gukonjeshwa, aside sulfurike yibanze yongewe kuri NaCl solide kugirango ihite itanga umubare munini wibibyimba. Gazi yabyaye inyuzwa mumashanyarazi yumye irimo silika gel, hanyuma urupapuro rwipimisha pH rushyirwa kumpera yumye. Gel ya silika kumpera yimbere ihinduka icyatsi kibisi, kandi impapuro zipimishije pH nta gihinduka kigaragara (reba Ishusho 3). Ibi birerekana ko gaze ya HCl yakozwe yamamajwe rwose na gelika silika kandi ntabwo ihungira mukirere.
Igishushanyo cya 3 Ubushakashatsi ku rwego rwo gukoresha silika gel desiccant - hydrogen chloride
Silica gel yamamaza HCl ihinduka icyatsi kibisi yashyizwe mubizamini. Shira gel nshya ya silika yubururu muri test ya test, ongeramo aside hydrochloric acide, gelika silika nayo ihinduka ibara ryicyatsi kibisi, amabara yombi arimwe. Ibi byerekana gazi ya silika gel muri spherical yumye.
2 Gazi yabyaye inyuzwa mu muyoboro wumye urimo gelika ya silika ifite ibara, gelika ya silika ibara ihinduka ibara ry'ubururu-icyatsi kibisi, naho impapuro za litimus z'ubururu zirangije impapuro zipimishije ntizihinduka cyane, byerekana ko gaze ya SO2 yakozwe ifite yamamajwe rwose numupira wa silika gel kandi ntishobora guhunga.
FIG. 4 Ubushakashatsi bwerekana urugero rwo gukoresha silika gel desiccant - dioxyde de sulfure
Kuramo igice cy'umupira wa silika gishyire mumazi yatoboye. Nyuma yo kuringaniza byuzuye, fata amazi make kumpapuro yubururu. Impapuro zipimisha ntizihinduka cyane, byerekana ko amazi yatoboye adahagije kugirango desorora SO2 ivuye muri silika gel. Fata agace gato k'umupira wa silika gel hanyuma ushushe muri tube. Shira impapuro zitukura z'ubururu kumunwa wikizamini. Impapuro za litimus z'ubururu zihinduka umutuku, byerekana ko gushyushya bituma gaze ya SO2 ikurwa mu mupira wa silika gel, bityo bigatuma litmus ihinduka umutuku. Ubushakashatsi bwavuzwe haruguru bwerekana ko silika gel nayo igira ingaruka zikomeye za adsorption kuri SO2 cyangwa H2 SO3, kandi ntishobora gukoreshwa mukumisha gaze ya SO2.
2.4 Ubushakashatsi bwurwego rwo gukoresha silika gel desiccant - Dioxyde de Carbone
Nkuko bigaragara ku gishushanyo cya 5, sodium bicarbonate igisubizo gitonyanga fenolphthalein igaragara umutuku. Sodium bicarbonate ikomeye irashyuha kandi ivangwa rya gaze bivamo unyuzwa mu cyuma cyumye kirimo silika gel yumye. Gel ya silika ntabwo ihinduka cyane kandi sodium bicarbonate itonyanga hamwe na fenolphthalein yamamaza HCl. Cobalt ion muri gelika ya silika ifite ibara ikora igisubizo kibisi hamwe na Cl- hanyuma igenda ihinduka ibara, byerekana ko hariho gazi ya CO2 kumpera yumuyoboro wumye. Gel-icyatsi kibisi-icyatsi kibisi gishyirwa mumazi yatoboye, kandi gelika ya silika ifite ibara gahoro gahoro ihinduka umuhondo, byerekana ko HCl yamamajwe na gelika ya silika yajugunywe mumazi. Umubare muto wumuti wo hejuru wamazi wongewe kumuti wa nitrate ya silver ya acide na acide ya nitric kugirango ube imvura yera. Umubare muto wumuti wamazi ujugunywa kumurongo mugari wimpapuro za pH, hanyuma impapuro zipimisha zihinduka umutuku, byerekana ko igisubizo ari acide. Ubushakashatsi bwavuzwe haruguru bwerekana ko silika gel ifite adsorption ikomeye kuri gaze ya HCl. HCl ni molekile ikomeye cyane, kandi itsinda rya hydroxyl hejuru ya gelika ya silika naryo rifite polarite ikomeye, kandi byombi bishobora gukora imiyoboro ya hydrogène ya intermolecular cyangwa ikagira imikoranire ya dipole ikomeye cyane, bikavamo imbaraga zingana hagati yimiterere ya silika. gel na molekile ya HCl, silika gel rero ifite adsorption ikomeye ya HCl. Kubwibyo, silicone yumisha ntishobora gukoreshwa kugirango yumishe HCl, ni ukuvuga, gelika ya silika ntabwo itanga CO2 cyangwa igice cya CO2 gusa.
FIG. 5 Ubushakashatsi bwurwego rwo gukoresha silika gel desiccant - karuboni ya dioxyde
Kugirango ugaragaze adsorption ya silika gel kuri gaze karuboni, ubushakashatsi bukurikira burakomeje. Umupira wa silika gel mumashanyarazi yumye wavanyweho, igice kigabanywamo sodium bicarbonate yumuti utonyanga fenolphthalein. Umuti wa sodium bicarbonate wasizwe amabara. Ibi byerekana ko silika gel itanga karuboni ya dioxyde de carbone, hanyuma imaze gushonga mumazi, karuboni ya dioxyde de carbone ikabamo sodium bicarbonate, bigatuma sodium ya bicarbonate ishira. Igice gisigaye cyumupira wa silicone gishyuha mumiyoboro yumye, hanyuma gaze yavuyemo ikanyuzwa mumuti wa sodium bicarbonate itonyanga hamwe na fenolphthalein. Bidatinze, sodium bicarbonate yumuti ihinduka kuva umutuku uhinduka ibara. Ibi birerekana kandi ko silika gel igifite ubushobozi bwa adsorption ya gaze ya CO2. Nyamara, imbaraga za adsorption ya silika gel kuri CO2 ni nto cyane ugereranije na HCl, NH3 na SO2, kandi dioxyde de carbone irashobora kwamamazwa igice gusa mugihe cyibigeragezo ku gishushanyo cya 5. Impamvu ituma gelika silika ishobora kwamamaza igice cya CO2 birashoboka. iyo silika gel na CO2 bigize hydrogène intermolecular ihuza Si - OH… O = C. Kuberako atome ya karubone yo hagati ya CO2 ari sp Hybride, hamwe na atome ya silicon muri gelika ya silika ni sp3 hybrid, molekile yumurongo wa CO2 ntabwo ikorana neza nubuso bwa gelika ya silika, bikavamo imbaraga za adsorption ya silika gel kuri karuboni ya dioxyde. nto.
3.Gereranya hagati ya solubile ya gaze enye mumazi hamwe na adsorption kumiterere ya gelika ya silika Duhereye kubisubizo byubushakashatsi byavuzwe haruguru, urashobora kubona ko silika gel ifite ubushobozi bukomeye bwa ammonia, hydrogène chloride na dioxyde de sulfure, ariko imbaraga ntoya ya adsorption ya karubone (reba Imbonerahamwe 1). Ibi bisa nubushake bwa gaze enye mumazi. Ibi birashobora kuba kubera ko molekile zamazi zirimo hydroxy-OH, kandi hejuru ya gelika ya silika nayo ikungahaye kuri hydroxyl, kubwibyo gukomera kwi myuka ine mumazi birasa cyane na adsorption yayo hejuru ya gelika ya silika. Muri gaze eshatu za gaze ya amoniya, hydrogène chloride na dioxyde de sulfure, dioxyde de sulfure ifite imbaraga nkeya mu mazi, ariko nyuma yo gushyirwaho na gelika ya silika, biragoye cyane gutoroka muri gaze eshatu. Nyuma ya silika gel adsorbs ammonia na hydrogen chloride, irashobora gutwarwa namazi meza. Umwuka wa dioxyde de sulfure umaze kumenyeshwa na silika gel, biragoye gutwarwa namazi, kandi bigomba gushyukwa kugeza desorption biva hejuru ya silika gel. Kubwibyo, adsorption ya gaze enye hejuru ya silika gel igomba kubarwa mubyukuri.
4 Kubara ibyerekeranye n'imikoranire hagati ya silika gel na gaze enye bitangwa muri kwantumasi ya software ya ORCA [4] murwego rwimikorere yubucucike (DFT). Uburyo bwa DFT D / B3LYP / Def2 TZVP bwakoreshejwe mukubara uburyo bwimikoranire ningufu hagati ya gaze zitandukanye na gelika silika. Kugirango byoroshe kubara, silika gel solide igereranwa na molekile ya tetrameric orthosilicic. Ibisubizo byo kubara byerekana ko H2 O, NH3 na HCl byose bishobora gukora hydrogène hamwe nitsinda rya hydroxyl hejuru ya silika gel (reba Ishusho 6a ~ c). Zifite imbaraga zikomeye zo guhuza hejuru ya silika gel (reba Imbonerahamwe 2) kandi byoroshye kwerekanwa hejuru ya silika gel. Kubera ko ingufu zihuza NH3 na HCl zisa n'izya H2 O, koza amazi birashobora gutuma desorption ya molekile zombi. Kuri molekile ya SO2, imbaraga zayo zihuza ni -17.47 kJ / mol gusa, ni nto cyane ugereranije na molekile eshatu zavuzwe haruguru. Nyamara, ubushakashatsi bwemeje ko gaze ya SO2 yoroha cyane kuri gelika ya silika, ndetse no gukaraba ntibishobora kuyitesha agaciro, kandi gushyushya byonyine birashobora gutuma SO2 ihunga hejuru ya gelika ya silika. Kubwibyo, twakekaga ko SO2 ishobora guhuza H2 O hejuru ya gelika ya silika kugirango ibe ibice bya H2 SO3. Igishushanyo cya 6e cyerekana ko molekile ya H2 SO3 ikora imigozi itatu ya hydrogène hamwe na hydroxyl na atome ya ogisijeni hejuru ya gelika ya silika icyarimwe, kandi ingufu zihuza zingana na -76,63 kJ / mol, bisobanura impamvu SO2 yamamajwe kuri gelika ya silika biragoye kwikuramo amazi. CO2 itari polar ifite ubushobozi buke bwo guhuza hamwe na silika gel, kandi irashobora kwamamazwa igice gusa na silika gel. Nubwo ingufu zihuza H2 CO3 na silika gel nazo zageze kuri -65,65 kJ / mol, igipimo cya CO2 kuri H2 CO3 nticyari kinini, bityo igipimo cya adsorption ya CO2 nacyo cyaragabanutse. Birashobora kugaragara duhereye ku makuru yavuzwe haruguru ko polarite ya molekile ya gaze atariyo ngingo yonyine yo gusuzuma niba ishobora kwamamazwa na gelika ya silika, kandi isano ya hydrogène ikozwe hamwe na silika gel niyo mpamvu nyamukuru ituma adsorption ihamye.
Ibigize gelika ya silika ni SiO2 · nH2 O, ubuso bunini bwa silika gel hamwe nitsinda rya hydroxyl ikize hejuru hejuru bituma silika gel ishobora gukoreshwa nkumuti udafite uburozi ufite imikorere myiza, kandi ukoreshwa cyane mubikorwa no mubuzima . Muri iyi nyandiko, hemejwe mubice bibiri byubushakashatsi no kubara byerekana ko gelika silika ishobora adsorb NH3, HCl, SO2, CO2 nizindi myuka ikoresheje imiyoboro ya hydrogène intermolecular, bityo gelika silika ntishobora gukoreshwa mukumisha iyo myuka. Ibigize gelika ya silika ni SiO2 · nH2 O, ubuso bunini bwa silika gel hamwe nitsinda rya hydroxyl ikize hejuru hejuru bituma silika gel ishobora gukoreshwa nkumuti udafite uburozi ufite imikorere myiza, kandi ukoreshwa cyane mubikorwa no mubuzima . Muri iyi nyandiko, hemejwe mubice bibiri byubushakashatsi no kubara byerekana ko gelika silika ishobora adsorb NH3, HCl, SO2, CO2 nizindi myuka ikoresheje imiyoboro ya hydrogène intermolecular, bityo gelika silika ntishobora gukoreshwa mukumisha iyo myuka.
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FIG. 6 Uburyo bwimikoranire hagati ya molekile zitandukanye na silika gel yubuso bwabazwe nuburyo bwa DFT
Igihe cyo kohereza: Ugushyingo-14-2023
