Ulwazi mayelana nokuguga kwerabha

1. Kuyini ukuguga kwerabha? Lokhu kubonisani ebusweni?
Enkambisweni yokucubungula, ukugcinwa kanye nokusetshenziswa kwerabha kanye nemikhiqizo yayo, ngenxa yesenzo esibanzi sezici zangaphakathi nezangaphandle, izakhiwo zomzimba nezamakhemikhali kanye nezakhiwo zerabha ziyawohloka kancane kancane, futhi ekugcineni zilahlekelwa yinani lazo lokusetshenziswa. Lolu shintsho lubizwa ngokuthi ukuguga kwerabha. Ngaphezulu, lubonakala njengokuqhekeka, ukunamathela, ukuqina, ukuthamba, ukushoba, ukushintsha kombala, kanye nokukhula kwesikhunta.
2. Yiziphi izici ezithinta ukuguga kwerabha?
Izici ezibangela ukuguga kwerabha yilezi:
(a) I-oksijini nomoya-mpilo enjolobeni kuhlangana nokusabela kwe-free radical chain nama-molecule enjoloba, kanti i-molecule chain iyaphuka noma ixhumene kakhulu, okuholela ekushintsheni kwezakhiwo zerabha. I-oxidation ingenye yezizathu ezibalulekile zokuguga kwerabha.
(b) Umsebenzi wamakhemikhali we-ozone ne-ozone uphakeme kakhulu kunowe-oxygen, futhi uyabhubhisa kakhulu. Uphinde uphule uchungechunge lwama-molecule, kodwa umphumela we-ozone enjolobeni uyahlukahluka kuye ngokuthi injoloba ikhubazekile noma cha. Uma isetshenziswa enjolobeni ekhubazekile (ikakhulukazi injoloba engagcwalisiwe), imifantu iqonde ngqo esiqondisweni sesenzo sokucindezeleka, okungukuthi, okubizwa ngokuthi “uqhekeko lwe-ozone”; uma isetshenziswa enjolobeni ekhubazekile, kwakheka ifilimu ye-oxide kuphela ebusweni ngaphandle kokuqhekeka.
(c) Ukushisa: Ukuphakamisa izinga lokushisa kungabangela ukuqhekeka kokushisa noma ukuhlangana kwerabha ngokushisa. Kodwa umphumela oyisisekelo wokushisa ukusebenza. Thuthukisa izinga lokusabalala komoya-mpilo futhi usebenze ukusabela kwe-oxidation, ngaleyo ndlela kusheshiswe izinga lokusabela kwe-oxidation kwerabha, okuyinto evamile yokuguga - ukuguga kwe-oxygen ngokushisa.
(d) Ukukhanya: Uma igagasi lokukhanya lifushane, kulapho amandla eba maningi khona. Umonakalo ngerabha yimisebe ye-ultraviolet enamandla aphezulu. Ngaphezu kokubangela ngqo ukuqhekeka nokuxhumanisa uchungechunge lwama-molecule erabha, imisebe ye-ultraviolet ikhiqiza ama-free radical ngenxa yokumuncwa kwamandla okukhanya, okuqala futhi kusheshise inqubo yokusabela kweketanga lokubola. Ukukhanya kwe-Ultraviolet kusebenza njengokushisa. Esinye isici sesenzo sokukhanya (esihlukile esenzweni sokushisa) ukuthi kwenzeka kakhulu ebusweni berabha. Kumasampula anokuqukethwe okuphezulu kweglue, kuzoba nemifantu yenethiwekhi kuzo zombili izinhlangothi, okungukuthi, okubizwa ngokuthi “imifantu yangaphandle yengqimba ye-optical”.
(e) Ukucindezeleka kwemishini: Ngaphansi kwesenzo esiphindaphindwayo sokucindezeleka kwemishini, uchungechunge lwama-molecule enjoloba luzophulwa ukuze lukhiqize ama-free radicals, okuzoqala ukusabela kwe-oxidation chain futhi kwakheke inqubo ye-mechanochemical. Ukuqhekeka kwemishini kwamaketanga ama-molecule kanye nokusebenza kwemishini kwezinqubo ze-oxidation. Ukuthi yiliphi elinamandla kuncike ezimweni lapho libekwe khona. Ngaphezu kwalokho, kulula ukubangela ukuqhekeka kwe-ozone ngaphansi kwesenzo sokucindezeleka.
(f) Umswakama: Umphumela womswakama unezici ezimbili: irabha yonakala kalula uma ivezwa emvuleni emoyeni omanzi noma icwiliswe emanzini. Lokhu kungenxa yokuthi izinto ezincibilika emanzini kanye namaqembu amanzi acwebile erabha zikhishwa futhi zincibilikiswe ngamanzi. Zibangelwa yi-hydrolysis noma ukumuncwa. Ikakhulukazi ngaphansi kwesenzo esishintshashintshayo sokucwiliswa emanzini kanye nokuvezwa emoyeni, ukubhujiswa kwerabha kuzosheshiswa. Kodwa kwezinye izimo, umswakama awulimazi irabha, futhi unomthelela wokulibazisa ukuguga.
(g) Okunye: Kukhona imidiya yamakhemikhali, ama-ion ensimbi eguquguqukayo, imisebe enamandla aphezulu, ugesi kanye nebhayoloji, njll., ezithinta irabha.
3. Yiziphi izinhlobo zezindlela zokuhlola ukuguga ngerabha?
Ingahlukaniswa ngezigaba ezimbili:
(a) Indlela yokuhlola ukuguga yemvelo. Ihlukaniswe kabanzi ngokuthi ukuhlolwa kokuguga okusemoyeni, ukuhlolwa kokuguga okusheshayo okusemoyeni, ukuhlolwa kokuguga okugcinwe ngokwemvelo, indawo yemvelo (kufaka phakathi indawo egqitshwe, njll.) kanye nokuhlolwa kokuguga kwezinto eziphilayo.
(b) Indlela yokuhlola ukuguga okusheshayo kokwenziwa. Kokuguga okushisa, ukuguga kwe-ozone, ukuguga nge-photo, ukuguga kwesimo sezulu sokwenziwa, ukuguga kwe-photo-ozone, ukuguga kwezinto eziphilayo, imisebe enamandla aphezulu kanye nokuguga kukagesi, kanye nokuguga kwemidiya yamakhemikhali.
4. Yiliphi izinga lokushisa okufanele likhethwe ekuhlolweni kokuguga komoya oshisayo kwamakhemikhali ahlukahlukene enjoloba?
Kurabha yemvelo, izinga lokushisa lokuhlola livame ukuba ngu-50~100℃, ngerabha yokwenziwa, ivame ukuba ngu-50~150℃, kanti izinga lokushisa lokuhlola lamarabha athile akhethekile liphakeme. Isibonelo, irabha ye-nitrile isetshenziswa ku-70~150℃, kanti irabha ye-silicone fluorine ivame ukusetshenziswa ku-200~300℃. Ngamafuphi, kufanele kunqunywe ngokuya ngokuhlolwa.