Cov kws tshawb fawb tau tsim cov yas zoo ib yam li hlau - muaj zog tab sis tsis hnyav. Cov yas, uas cov kws tshuaj qee zaum hu ua polymers, yog ib chav kawm ntawm cov saw ntev uas ua los ntawm cov chav luv luv hu ua monomers. Tsis zoo li cov polymers yav dhau los uas muaj tib lub zog, cov khoom tshiab tsuas yog los hauv daim ntawv membrane. Nws kuj tseem muaj cua nkag tau zoo dua 50 npaug ntawm cov yas uas tsis nkag tau hauv khw. Lwm qhov tseem ceeb ntawm cov polymer no yog nws qhov yooj yim ntawm kev sib xyaw. Cov txheej txheem, uas tshwm sim ntawm chav tsev kub, tsuas yog xav tau cov khoom pheej yig xwb, thiab cov polymer tuaj yeem tsim tau ntau hauv cov ntawv loj uas tsuas yog nanometers tuab. Cov kws tshawb fawb tshaj tawm lawv cov kev tshawb pom Lub Ob Hlis 2 hauv phau ntawv xov xwm Nature.
Cov khoom siv no hu ua polyamide, uas yog ib txoj hlua khi ua ke ntawm cov amide molecular units (amides yog cov pab pawg tshuaj nitrogen uas txuas nrog cov pa roj carbon uas muaj oxygen). Cov polymers no suav nrog Kevlar, ib hom fiber siv los ua cov tsho tiv thaiv mos txwv, thiab Nomex, ib hom ntaub uas tiv taus hluav taws. Ib yam li Kevlar, cov polyamide molecules hauv cov khoom siv tshiab no txuas nrog ib leeg los ntawm cov hydrogen bonds raws tag nrho lawv cov saw hlau, uas ua rau cov khoom siv muaj zog dua.
"Lawv lo ua ke zoo li Velcro," tus sau thawj coj Michael Strano, tus kws ua tshuaj lom neeg ntawm MIT hais. Kev rhuav cov ntaub ntawv tsis yog tsuas yog yuav tsum tau rhuav cov saw hlau molecular xwb, tab sis kuj tseem yuav tsum kov yeej cov hydrogen bonds loj loj uas nkag mus rau hauv tag nrho cov polymer bundle.
Ntxiv mus, cov polymers tshiab tuaj yeem tsim cov flakes. Qhov no ua rau cov khoom siv yooj yim rau kev ua, vim nws tuaj yeem ua rau hauv cov zaj duab xis nyias lossis siv ua cov txheej txheej nyias nyias. Cov polymers ib txwm muaj feem loj hlob ua cov saw hlau, lossis rov ua ceg thiab txuas ua peb qhov ntev, tsis hais txog kev taw qhia. Tab sis Strano cov polymers loj hlob hauv txoj kev tshwj xeeb hauv 2D los tsim cov nanosheets.
"Koj puas tuaj yeem sau ua ke rau ntawm daim ntawv? Feem ntau, koj ua tsis tau kom txog thaum peb ua haujlwm," Strano hais. "Yog li, peb pom ib txoj hauv kev tshiab." Hauv txoj haujlwm tsis ntev los no, nws pab neeg tau kov yeej qhov teeb meem los ua kom qhov kev sib sau ua ke ob sab no ua tau.
Qhov laj thawj uas polyaramides muaj cov qauv planar yog tias kev tsim cov polymer cuam tshuam nrog lub tshuab hu ua autocatalytic templating: thaum cov polymer ntev thiab lo rau cov monomer building blocks, cov polymer network loj hlob ua rau cov monomers tom qab ntawd tsuas yog Sib Koom Ua Ke hauv txoj kev zoo kom txhawb nqa kev sib koom ua ke ntawm ob.dimensional qauv. Cov kws tshawb fawb tau qhia tias lawv tuaj yeem yooj yim txheej cov polymer hauv cov tshuaj rau ntawm wafers los tsim cov laminates dav tsawg dua 4 nanometers tuab. Qhov ntawd yuav luag ib lab qhov tuab ntawm cov ntawv ua haujlwm ib txwm muaj.
Yuav kom paub txog cov khoom siv kho tshuab ntawm cov khoom siv polymer, cov kws tshawb fawb tau ntsuas lub zog uas yuav tsum tau siv los tho qhov hauv daim ntawv uas dai nrog rab koob me me. Cov polyamide no yeej tawv dua li cov polymers ib txwm muaj xws li nylon, cov ntaub siv los ua parachutes. Qhov zoo kawg nkaus, nws siv ob npaug ntawm lub zog kom tshem tawm cov polyamide muaj zog heev no li cov hlau uas tuab tib yam. Raws li Strano, cov tshuaj no tuaj yeem siv ua cov txheej tiv thaiv rau ntawm cov hlau, xws li cov veneers tsheb, lossis ua cov lim dej kom lim dej. Hauv qhov kev ua haujlwm tom kawg, daim nyias nyias lim dej zoo tagnrho yuav tsum nyias tab sis muaj zog txaus kom tiv taus qhov siab siab yam tsis muaj cov khoom me me, cov khoom tsis zoo rau hauv peb qhov khoom kawg - qhov haum zoo meej rau cov khoom siv polyamide no.
Yav tom ntej, Strano vam tias yuav nthuav dav txoj kev polymerization mus rau ntau hom polymers dhau ntawm qhov Kevlar analog no. "Polymers nyob ib puag ncig peb," nws hais. "Lawv ua txhua yam." Xav txog kev tig ntau hom polymers sib txawv, txawm tias cov khoom txawv txawv uas tuaj yeem ua hluav taws xob lossis lub teeb, mus rau hauv cov yeeb yaj kiab nyias uas tuaj yeem npog ntau yam nto, nws ntxiv. "Vim yog lub tshuab tshiab no, tej zaum lwm hom polymers tam sim no tuaj yeem siv tau," Stano hais.
Hauv lub ntiaj teb uas muaj cov yas nyob ib puag ncig, lub zej zog muaj laj thawj zoo siab txog lwm cov polymer tshiab uas nws cov khoom siv kho tshuab tsis zoo li qub, Strano hais. Cov aramid no ruaj khov heev, uas txhais tau tias peb tuaj yeem hloov cov yas txhua hnub, los ntawm cov xim pleev xim rau cov hnab mus rau cov khoom noj khoom haus, nrog cov khoom siv tsawg dua thiab muaj zog dua. Strano ntxiv tias los ntawm qhov pom ntawm kev ruaj khov, cov polymer 2D muaj zog heev no yog ib kauj ruam mus rau txoj kev zoo los tso lub ntiaj teb ntawm cov yas.
Shi En Kim (raws li nws feem ntau hu ua Kim) yog ib tug kws sau ntawv txog kev tshawb fawb ywj pheej uas yug hauv tebchaws Malaysia thiab yog ib tug neeg ua haujlwm pab dawb hauv Popular Science Spring 2022. Nws tau sau ntau yam txog cov ncauj lus xws li kev siv cov ntaub ntawm cov kab laug sab - tib neeg lossis cov kab laug sab lawv tus kheej - mus rau cov neeg sau khib nyiab hauv qhov chaw sab nraud.
Boeing lub dav hlau Starliner tseem tsis tau mus txog Chaw Nres Tsheb Thoob Ntiaj Teb, tab sis cov kws tshaj lij muaj kev cia siab tias yuav muaj kev sim dav hlau zaum thib peb.
Peb yog ib tug neeg koom nrog hauv Amazon Services LLC Associates Program, ib qho kev tshaj tawm koom tes uas tsim los muab txoj hauv kev rau peb kom tau txais cov nqi los ntawm kev txuas mus rau Amazon.com thiab cov chaw koom tes. Kev sau npe lossis siv lub xaib no suav tias yog kev lees txais peb Cov Lus Cog Tseg ntawm Kev Pabcuam.
Lub sijhawm tshaj tawm: Tsib Hlis-19-2022