Izazinzulu zenze iplastiki elingana nentsimbi — eqinileyo kodwa enganzima. Iiplastiki, ezithi iingcali zamachiza ngamanye amaxesha zibize iipolymers, ziluhlobo lweemolekyuli ezineetyathanga ezinde ezenziwe ngeeyunithi eziphindaphindayo ezibizwa ngokuba ziimonomers. Ngokungafaniyo neepolymers zangaphambili ezinamandla afanayo, izinto ezintsha ziza kuphela kwimo ye-membrane. Ikwanomoya ongaphezulu ngokuphindwe ka-50 kuneplastiki engenamanzi kakhulu kwimarike. Enye into ephawulekayo yale polymer kukulula kwayo kokwenziwa. Inkqubo, eyenzeka kubushushu begumbi, ifuna kuphela izinto ezingabizi kakhulu, kwaye ipolymer inokuveliswa ngobuninzi kwiishiti ezinkulu ezinobukhulu be-nanometers kuphela. Abaphandi baxela iziphumo zabo nge-2 kaFebruwari kwiphephancwadi i-Nature.
Izinto ezithethwayo zibizwa ngokuba yi-polyamide, inethiwekhi enemisonto yeeyunithi zemolekyuli ze-amide (ii-amide ngamaqela eekhemikhali ze-nitrogen anamathele kwiiathom zekhabhoni ezibotshelelwe yi-oxygen-bond). Ezi polymer ziquka iKevlar, ifayibha esetyenziselwa ukwenza iivesti ezikhusela iimbumbulu, kunye neNomex, ilaphu elingatshiyo. NjengeKevlar, iimolekyuli ze-polyamide kwizinto ezintsha zidibene ngeebhondi ze-hydrogen kulo lonke ubude beetsheyini zazo, nto leyo ephucula amandla ezinto.
“Zinamathelana njengeVelcro,” utshilo umbhali okhokelayo uMichael Strano, injineli yeekhemikhali yeMIT. Ukukrazula izinto akufuneki nje kuphela ukuqhawula imixokelelwane yeemolekyuli nganye, kodwa kukwafuneka ukoyisa iibhondi ezinkulu zehydrogen eziphakathi kweemolekyuli ezityhutyha yonke i-polymer bundle.
Ukongeza, iipolymers ezintsha zinokwenza ngokuzenzekelayo iiflakes. Oku kwenza kube lula ukuzicubungula, njengoko zinokwenziwa zibe ziifilimu ezincinci okanye zisetyenziswe njengengubo yomphezulu wefilimu encinci. Iipolymers zemveli zihlala zikhula njengeetyathanga ezithe tyaba, okanye ziqhagamshele ngokuphindaphindiweyo kwiimilinganiselo ezintathu, nokuba zijongise phi na. Kodwa iipolymers zikaStrano zikhula ngendlela eyahlukileyo kwi-2D ukuze zenze ii-nanosheets.
“Ngaba ningakwazi ukuqokelelana ephepheni? Kuvela ukuba, kwiimeko ezininzi, aninakukwenza oko de kube ngumsebenzi wethu,” utshilo uStrano. “Ngoko ke, sifumene indlela entsha.” Kulo msebenzi wakutshanje, iqela lakhe loyise umqobo ukuze kwenzeke ukuba olu luhlu lube macala mabini lube nokwenzeka.
Isizathu sokuba ii-polyaramides zibe nesakhiwo esicwangcisiweyo kukuba ukwenziwa kwe-polymer kubandakanya indlela ebizwa ngokuba yi-autocatalytic templating: njengoko i-polymer ikhula kwaye inamathela kwiibhloko zokwakha ze-monomer, inethiwekhi ye-polymer ekhulayo ibangela ii-monomers ezilandelayo ukuba zidibanise kwicala elifanelekileyo kuphela ukuqinisa umanyano lwesakhiwo esinemilinganiselo emibini. Abaphandi babonise ukuba banokugquma i-polymer ngokulula kwisisombululo kwii-wafers ukwenza ii-laminates ezibanzi nge-intshi ezingaphantsi kwe-4 nanometers ubukhulu. Oko kuphantse kube yi-1 yezigidi ubukhulu bephepha leofisi eliqhelekileyo.
Ukuze balinganise iimpawu zoomatshini zezinto zepolymer, abaphandi balinganise amandla afunekayo ukubhoboza imingxunya kwiphepha elixhonyiweyo lezinto ngenaliti encinci. Le polyamide iqinile ngokwenene kuneepolymer zemveli ezifana nenylon, ilaphu elisetyenziselwa ukwenza iiparashuti. Okuphawulekayo kukuba, kuthatha amandla aphindwe kabini ukukhulula le polyamide enamandla kakhulu kunentsimbi enobukhulu obufanayo. Ngokutsho kukaStrano, le nto ingasetyenziswa njengengubo yokukhusela kwiindawo zesinyithi, ezifana neeveneers zemoto, okanye njengesihluzo sokucoca amanzi. Kumsebenzi wokugqibela, i-membrane yesihluzo efanelekileyo kufuneka ibe ncinci kodwa yomelele ngokwaneleyo ukumelana noxinzelelo oluphezulu ngaphandle kokuvuza ungcoliseko oluncinci, oluphazamisayo kumthombo wethu wokugqibela - oluhambelana kakuhle nale polyamide.
Kwixesha elizayo, uStrano unethemba lokwandisa indlela yokwenza i-polymerization kwiipolymers ezahlukeneyo ngaphaya kwale analog yeKevlar. “Iipolymers zisijikelezile,” utshilo. “Zenza yonke into.” Khawuthelekelele uguqula iintlobo ezininzi ezahlukeneyo zeepolymers, kwanezo zingaqhelekanga ezinokuqhuba umbane okanye ukukhanya, zibe ziifilimu ezincinci ezinokugubungela iindawo ezahlukeneyo, wongeza athi. “Ngenxa yale ndlela intsha, mhlawumbi ezinye iintlobo zeepolymers ngoku zingasetyenziswa,” utshilo uStano.
Kwihlabathi elijikelezwe ziiplastiki, uluntu lunesizathu sokuvuya ngenye ipolymer entsha eneempawu zoomatshini ezingaqhelekanga, utshilo uStrano. Le aramid ihlala ixesha elide kakhulu, oko kuthetha ukuba singatshintsha iiplastiki zemihla ngemihla, ukusuka kwiipeyinti ukuya kwiingxowa ukuya kwiipakethe zokutya, ngezinto ezimbalwa neziqinileyo. UStrano wongeze ngelithi ngokwembono yozinzo, le polymer ye-2D enamandla kakhulu linyathelo eliya kwicala elifanelekileyo lokukhulula ihlabathi kwiplastiki.
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Ixesha lokuthumela: Meyi-19-2022