Asayansi apanga pulasitiki yofanana ndi chitsulo — yolimba koma osati yolemera. Mapulasitiki, omwe akatswiri a zamankhwala nthawi zina amatcha ma polima, ndi gulu la mamolekyu atali opangidwa ndi mayunitsi afupiafupi obwerezabwereza otchedwa ma monomers. Mosiyana ndi ma polima akale amphamvu yomweyo, chinthu chatsopanochi chimabwera mu mawonekedwe a nembanemba yokha. Chimakhalanso chopanda mpweya nthawi 50 kuposa pulasitiki yosalowa madzi kwambiri pamsika. Chinthu china chodziwika bwino cha polima iyi ndi kuphweka kwake kopanga. Njirayi, yomwe imachitika kutentha kwa chipinda, imafuna zinthu zotsika mtengo zokha, ndipo polima imatha kupangidwa mochuluka m'mapepala akuluakulu omwe ndi okhuthala a nanometer okha. Ofufuzawo akufotokoza zomwe apeza pa Feb. 2 mu magazini ya Nature.
Zinthu zomwe zikukambidwazi zimatchedwa polyamide, netiweki yolumikizidwa ndi mayunitsi a mamolekyu a amide (ma amide ndi magulu a mankhwala a nayitrogeni olumikizidwa ku maatomu a kaboni olumikizidwa ndi okosijeni). Ma polima oterewa akuphatikizapo Kevlar, ulusi womwe umagwiritsidwa ntchito popanga ma vest osapsa ndi zipolopolo, ndi Nomex, nsalu yosapsa ndi moto. Monga Kevlar, mamolekyu a polyamide omwe ali mu chinthu chatsopanocho amalumikizidwa wina ndi mnzake ndi ma bond a hydrogen m'litali lonse la unyolo wawo, zomwe zimawonjezera mphamvu yonse ya chinthucho.
"Zimalumikizana ngati Velcro," anatero wolemba wamkulu Michael Strano, mainjiniya wa mankhwala a MIT. Kung'amba zinthu sikutanthauza kungoswa maunyolo a mamolekyulu payokha, komanso kuthana ndi ma bond akuluakulu a hydrogen omwe amalowa mu polima yonse.
Kuphatikiza apo, ma polima atsopano amatha kupanga ma flakes okha. Izi zimapangitsa kuti zinthuzo zikhale zosavuta kuzikonza, chifukwa zimatha kupangidwa kukhala mafilimu opyapyala kapena kugwiritsidwa ntchito ngati chophimba chapamwamba cha filimu yopyapyala. Ma polima achikhalidwe amakonda kukula ngati unyolo wolunjika, kapena nthambi ndi kulumikizana mobwerezabwereza m'magawo atatu, mosasamala kanthu za komwe akuyang'ana. Koma ma polima a Strano amakula mwanjira yapadera mu 2D kuti apange ma nanosheets.
“Kodi mungaphatikizepo pepala? Nthawi zambiri, simungathe kuchita izi mpaka ntchito yathu itatha,” anatero Strano. “Chifukwa chake, tapeza njira yatsopano.” Mu ntchito yaposachedwa iyi, gulu lake linagonjetsa chopinga kuti kusonkhanitsa kumeneku kwa mbali ziwiri kutheke.
Chifukwa chake ma polyaramides ali ndi kapangidwe kolinganizika ndichakuti kapangidwe ka ma polymer kamaphatikizapo njira yotchedwa autocatalytic templating: pamene polymer imatalika ndikumamatira ku mabuloko omangira a monomer, netiweki ya polymer yomwe ikukula imapangitsa ma monomers otsatira kuti agwirizane bwino kuti alimbikitse mgwirizano wa kapangidwe ka magawo awiri. Ofufuzawo adawonetsa kuti amatha kupaka polima mosavuta mu yankho pa ma wafers kuti apange ma laminates okwana mainchesi 4 makulidwe osakwana nanometers 4. Ndiwo makulidwe pafupifupi miliyoni imodzi kuposa pepala wamba laofesi.
Kuti apeze mphamvu ya makina a zinthu za polima, ofufuzawo anayeza mphamvu yofunikira kuti aboole mabowo mu pepala lopachikidwa ndi singano yaying'ono. Polyamide iyi ndi yolimba kwambiri kuposa ma polima achikhalidwe monga nayiloni, nsalu yomwe imagwiritsidwa ntchito popanga ma parachuti. Chodabwitsa n'chakuti, pamafunika mphamvu yowirikiza kawiri kuti mutsegule polyamide iyi yolimba kwambiri kuposa chitsulo cha makulidwe omwewo. Malinga ndi Strano, chinthuchi chingagwiritsidwe ntchito ngati chophimba choteteza pamwamba pa zitsulo, monga ma veneer agalimoto, kapena ngati fyuluta yoyeretsera madzi. Pa ntchito yomalizayi, nembanemba yoyenera ya fyuluta iyenera kukhala yopyapyala koma yolimba mokwanira kuti ipirire kupsinjika kwakukulu popanda kutulutsa zodetsa zazing'ono, zosokoneza mu gawo lathu lomaliza - yoyenera bwino zinthu za polimamide izi.
M'tsogolomu, Strano akuyembekeza kukulitsa njira ya polymerization ku ma polima osiyanasiyana kupitirira Kevlar analog iyi. "Ma polima ali ponseponse," adatero. "Amachita chilichonse." Tangoganizani kusandutsa mitundu yosiyanasiyana ya ma polima, ngakhale achilendo omwe amatha kuyendetsa magetsi kapena kuwala, kukhala mafilimu opyapyala omwe amatha kuphimba malo osiyanasiyana, akuwonjezera. "Chifukwa cha njira yatsopanoyi, mwina mitundu ina ya ma polima tsopano ingagwiritsidwe ntchito," adatero Stano.
M'dziko lozunguliridwa ndi mapulasitiki, anthu ali ndi chifukwa chosangalalira ndi polima ina yatsopano yomwe mphamvu zake sizili zachilendo, anatero Strano. Aramid iyi ndi yolimba kwambiri, zomwe zikutanthauza kuti titha kusintha mapulasitiki a tsiku ndi tsiku, kuyambira utoto mpaka matumba mpaka ma phukusi a chakudya, ndi zinthu zochepa komanso zolimba. Strano anawonjezera kuti potengera momwe zinthu zilili, polima ya 2D iyi yamphamvu kwambiri ndi sitepe yoyenera yomasula dziko ku pulasitiki.
Shi En Kim (monga momwe amatchulidwira Kim) ndi wolemba nkhani za sayansi wobadwira ku Malaysia komanso wophunzira ntchito yolemba nkhani za Popular Science Spring 2022. Walemba zambiri pa mitu yosiyanasiyana kuyambira kugwiritsa ntchito zinthu zachilendo za ukonde—anthu kapena akangaude okha—mpaka kusonkhanitsa zinyalala m'mlengalenga.
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Ndife otenga nawo mbali mu Amazon Services LLC Associates Program, pulogalamu yotsatsa yogwirizana yomwe idapangidwa kuti ipereke njira yoti tipeze ndalama polumikizana ndi Amazon.com ndi masamba ogwirizana. Kulembetsa kapena kugwiritsa ntchito tsamba ili kumatanthauza kuvomereza Migwirizano Yathu Yogwirira Ntchito.
Nthawi yotumizira: Meyi-19-2022