Izinkuni zemvelo nensimbi kube yizinto zokwakha ezibalulekile kubantu izinkulungwane zeminyaka. Ama-polymers okwenziwa esiwabiza ngokuthi amapulasitiki ayizinto ezintsha ezisanda kuqhuma ngekhulu lama-20.
Zombili izinsimbi kanye nepulasitiki zinezakhiwo ezifanele ukusetshenziswa kwezimboni kanye nezentengiselwano. Izinsimbi ziqinile, ziqinile, futhi ngokuvamile ziyakwazi ukumelana nomoya, amanzi, ukushisa, kanye nokucindezeleka okuqhubekayo. Kodwa-ke, zidinga nezinsiza ezengeziwe (okusho ukuthi zibiza kakhulu) ukukhiqiza nokucwenga imikhiqizo yazo. Ipulasitiki inikeza eminye yemisebenzi yensimbi ngenkathi idinga isisindo esincane futhi ishibhile kakhulu ukuyikhiqiza. Izakhiwo zazo zingenziwa ngezifiso cishe nganoma yikuphi ukusetshenziswa. Kodwa-ke, ipulasitiki yezentengiselwano eshibhile yenza izinto zokwakha ezimbi kakhulu: izinto zepulasitiki aziyona into enhle, futhi akekho ofuna ukuhlala endlini yepulasitiki. Ngaphezu kwalokho, zivame ukucwengisiswa ngamafutha angaphansi komhlaba.
Kwezinye izinhlelo zokusebenza, ukhuni lwemvelo lungancintisana nezinsimbi kanye nepulasitiki. Imindeni eminingi yakhiwe ngohlaka lokhuni. Inkinga ukuthi ukhuni lwemvelo luthambile kakhulu futhi lonakaliswa kalula ngamanzi ukuze luthathe indawo yepulasitiki kanye nensimbi isikhathi esiningi. Iphepha lakamuva elishicilelwe kumagazini i-Matter lihlola ukudalwa kwezinto zokhuni eziqinile ezinqoba lezi mingcele. Lolu cwaningo lufinyelele esiphethweni sokudalwa kwemimese nezipikili zokhuni. Ungakanani ummese wokhuni futhi uzowusebenzisa maduze nje?
Isakhiwo sokhuni esinemicu sakhiwe cishe yi-cellulose engu-50%, i-polymer yemvelo enezakhiwo ezinhle zokuqina ngokombono. Ingxenye esele yesakhiwo sokhuni ikakhulukazi i-lignin ne-hemicellulose. Ngenkathi i-cellulose yakha imicu emide, eqinile enikeza ukhuni umgogodla wamandla ayo emvelo, i-hemicellulose ayinaso isakhiwo esiqinile futhi ngaleyo ndlela ayinikezi lutho emandleni okhuni. I-Lignin igcwalisa izikhala phakathi kwemicu ye-cellulose futhi yenza imisebenzi ewusizo yokhuni oluphilayo. Kodwa ngenhloso yabantu yokuhlanganisa ukhuni nokubopha imicu ye-cellulose yayo ngokuqinile, i-lignin yaba yisithiyo.
Kulesi sifundo, ukhuni lwemvelo lwenziwa ukhuni oluqinile (HW) ngezinyathelo ezine. Okokuqala, ukhuni lubiliswa ku-sodium hydroxide kanye ne-sodium sulfate ukuze kususwe i-hemicellulose kanye ne-lignin. Ngemva kwalokhu kwelashwa ngamakhemikhali, ukhuni luba luqinile ngokulucindezela ngokucindezela amahora amaningana ekushiseni kwegumbi. Lokhu kunciphisa izikhala zemvelo noma ama-pores okhunini futhi kuthuthukisa ukubopha kwamakhemikhali phakathi kwemicu ye-cellulose eseduze. Okulandelayo, ukhuni lucindezelwa ku-105° C (221° F) amahora ambalwa ukuze kuqedwe ukuqina, bese lomiswa. Ekugcineni, ukhuni lucwiliswa ku-oyili yamaminerali amahora angu-48 ukuze umkhiqizo oqediwe ungangeni manzi.
Isici esisodwa semishini sezinto zokwakha ubulukhuni bokugoba, okuyisilinganiso sekhono lazo lokumelana nokuguquguquka lapho zicindezelwa ngamandla. Idayimane liqinile kunensimbi, liqinile kunegolide, liqinile kunezinkuni, futhi linzima kune-foam yokupakisha. Phakathi kokuhlolwa okuningi kobunjiniyela okusetshenziselwa ukunquma ubulukhuni, njengobulukhuni bukaMohs obusetshenziswa ku-gemology, ukuhlolwa kweBrinell kungenye yazo. Umqondo walo ulula: ibhere lebhola lensimbi eliqinile licindezelwa endaweni yokuhlola ngamandla athile. Linganisa ububanzi bokugoba okujikelezayo okudalwe yibhola. Inani lobulukhuni beBrinell libalwa kusetshenziswa ifomula yezibalo; uma sikhuluma kancane, lapho ibhola lishaya umgodi omkhulu, kulapho izinto zithambile khona. Kulesi sivivinyo, i-HW inzima ngokuphindwe ka-23 kunezinkuni zemvelo.
Iningi lezinkuni zemvelo ezingaphathwanga kahle lizomunca amanzi. Lokhu kungandisa ukhuni futhi ekugcineni kubhubhise izakhiwo zalo. Abalobi basebenzise ukucwilisa amaminerali izinsuku ezimbili ukwandisa ukumelana kwamanzi kwe-HW, okwenza kube nokungathandi amanzi (“ukwesaba amanzi”). Ukuhlolwa kokungathandi amanzi kuhilela ukubeka ithonsi lamanzi phezu kobuso. Lapho ubuso bungathandi amanzi kakhulu, amaconsi amanzi aba yindilinga kakhulu. Ngakolunye uhlangothi, ubuso obungathandi amanzi (“othanda amanzi”), busakaza amaconsi aphansi (futhi kamuva bumunca amanzi kalula). Ngakho-ke, ukucwilisa amaminerali akugcini nje ngokwandisa kakhulu ukungathandi amanzi kwe-HW, kodwa futhi kuvimbela ukhuni ekumunceni umswakama.
Kwezinye izivivinyo zobunjiniyela, imimese ye-HW yenze kangcono kancane kunemimese yensimbi. Ababhali bathi ummese we-HW ubukhali cishe ngokuphindwe kathathu kunommese otholakala kwezentengiselwano. Kodwa-ke, kukhona isixwayiso ngalo mphumela othakazelisayo. Abacwaningi baqhathanisa imimese yetafula, noma lokho esingakubiza ngokuthi imimese yebhotela. Lokhu akuhloselwe ukuba kube bukhali kakhulu. Ababhali bakhombisa ividiyo yommese wabo usika i-steak, kodwa umuntu omdala onamandla angase asike i-steak efanayo ngohlangothi olubuthuntu lwefoloko yensimbi, futhi ummese we-steak ungasebenza kangcono kakhulu.
Kuthiwani ngezipikili? Isipikili esisodwa se-HW kubonakala sengathi singashaywa kalula sibe yinqwaba yamapulangwe amathathu, yize singenazo imininingwane eminingi njengoba kulula uma siqhathaniswa nezipikili zensimbi. Izipikili zokhuni zingabamba amapulangwe ndawonye, zimelane namandla angawadabula, ngokuqina okufanayo nezipikili zensimbi. Nokho, ekuhlolweni kwazo, amabhodi kuzo zombili izimo ahluleka ngaphambi kokuba noma yisiphi isipikili sehluleke, ngakho-ke izipikili eziqinile azizange zivele.
Ingabe izinzipho ze-HW zingcono ngezinye izindlela? Izikhonkwane zokhuni zilula, kodwa isisindo sesakhiwo asishukunyiswa ngokuyinhloko yisisindo sezikhonkwane ezisibamba ndawonye. Izikhonkwane zokhuni ngeke zigqwale. Kodwa-ke, ngeke zithinteke ngamanzi noma zibole.
Akungabazeki ukuthi umbhali usungule inqubo yokwenza ukhuni lube namandla kunokhuni lwemvelo. Kodwa-ke, ukusetshenziswa kwehadiwe kunoma yimuphi umsebenzi othile kudinga ukutadisha okwengeziwe. Ingabe kungaba okushibhile futhi kungabi nazinsiza njengepulasitiki? Ingabe kungaba nokuncintisana nezinto zensimbi eziqinile, ezikhangayo, nezingasetshenziswa kabusha ngokungenamkhawulo? Ucwaningo lwabo luphakamisa imibuzo ethakazelisayo. Ubunjiniyela obuqhubekayo (futhi ekugcineni imakethe) buzoyiphendula.
Isikhathi sokuthunyelwe: Ephreli-13-2022
