Cov kws tshawb fawb tau tsim cov yas sib npaug rau cov hlau - muaj zog tab sis tsis hnyav.Plastics, uas qee zaum chemists hu ua polymers, yog ib chav kawm ntawm cov saw ntev molecules ua los ntawm luv luv rov qab units hu ua monomers.Tsis zoo li yav dhau los polymers ntawm tib lub zog, cov khoom tshiab nkaus xwb. los hauv daim ntawv membrane.Nws tseem yog 50 lub sij hawm ntau airtight tshaj qhov feem ntau impermeable yas ntawm lub khw.Lwm yam tseem ceeb ntawm no polymer yog nws yooj yim ntawm synthesis.Cov txheej txheem, uas yuav siv sij hawm qhov chaw nyob rau hauv chav tsev kub, yuav tsum tau tsuas yog cov khoom pheej yig, thiab cov polymer tuaj yeem ua tau loj-tsim nyob rau hauv cov ntawv loj uas tsuas yog nanometers tuab.Cov kws tshawb fawb qhia lawv qhov kev tshawb pom Lub Ob Hlis 2 hauv phau ntawv Journal Nature.
Cov khoom hauv nqe lus nug yog hu ua polyamide, cov xov sib txuas ntawm amide molecular units (amides yog cov tshuaj lom neeg nitrogen txuas nrog oxygen-bonded carbon atoms). Cov polymers xws li Kevlar, fiber ntau siv los ua cov tsho tiv thaiv mos txwv, thiab Nomex, hluav taws kub- resistant ntaub.zoo li Kevlar, cov polyamide molecules nyob rau hauv cov khoom tshiab yog txuas rau ib leeg los ntawm hydrogen bonds raws li tag nrho ntev ntawm lawv chains, uas txhim khu lub zuag qhia tag nrho lub zog ntawm cov khoom.
"Lawv lo ua ke zoo li Velcro," tus kws sau ntawv Michael Strano, tus kws tshaj lij tshuaj tshuaj MIT tau hais.Tearing cov ntaub ntawv yuav tsum tsis yog tsuas yog rhuav tshem cov saw hlau molecular xwb, tab sis tseem kov yeej cov kev sib tshuam loj heev ntawm hydrogen bonds uas permeate tag nrho cov khoom polymer.
Tsis tas li ntawd, cov polymers tshiab tuaj yeem ua cov flakes.Qhov no ua rau cov khoom siv tau yooj yim, vim nws tuaj yeem ua rau hauv cov yeeb yaj kiab nyias lossis siv los ua cov yeeb yaj kiab nyias txheej txheej.Traditional polymers zoo li loj hlob raws li cov kab sib txuas, lossis rov ua cov ceg ntoo thiab txuas hauv peb qhov ntev, tsis hais txog kev taw qhia.Tab sis Strano cov polymers loj hlob nyob rau hauv ib txoj kev tshwj xeeb hauv 2D los ua nanosheets.
“Koj puas tuaj yeem sau rau ntawm ib daim ntawv?Nws hloov tawm, feem ntau, koj ua tsis tau kom txog thaum peb ua haujlwm," Strano hais. "Yog li, peb nrhiav tau lub tshuab tshiab."Hauv kev ua 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 ua tau.
Yog vim li cas polyaramides muaj cov qauv qauv yog tias polymer synthesis koom nrog lub tshuab hu ua autocatalytic templating: raws li cov polymer lengthens thiab sticks rau cov monomer tsev blocks, cov polymer loj hlob hauv lub network induces tom ntej monomers tsuas yog muab tso rau hauv txoj cai coj los ntxiv dag zog rau lub koom haum ntawm lub tuam txhab. two.dimensional structure.Cov kws tshawb fawb tau pom tias lawv tuaj yeem yooj yim txheej txheej polymer hauv kev daws rau wafers los tsim ib nti-dav laminates tsawg dua 4 nanometers tuab.Qhov ntawd yog yuav luag ib lab lub thickness ntawm cov ntawv ua haujlwm li niaj zaus.
Txhawm rau kom muaj nuj nqis ntawm cov khoom siv hluav taws xob ntawm cov khoom siv polymer, cov kws tshawb fawb tau ntsuas lub zog yuav tsum tau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm Nws yuav siv sij hawm ob zaug ntau zog kom unscrew no super-muaj zog polyamide li hlau ntawm tib tuab tuab.Raws li Strano, cov tshuaj yuav siv tau raws li ib tug tiv thaiv txheej ntawm hlau nto, xws li lub tsheb veneers, los yog raws li ib tug lim kom huv si dej. Hauv kev ua haujlwm tom kawg, qhov zoo tshaj plaws lim membrane yuav tsum nyias nyias tab sis muaj zog txaus los tiv thaiv kev kub ntxhov yam tsis muaj qhov me me, tsis muaj paug paug rau hauv peb cov khoom kawg - ib qho zoo meej rau cov khoom siv polyamide no.
Nyob rau yav tom ntej, Strano vam tias yuav txuas ntxiv cov txheej txheem polymerization rau cov polymers sib txawv tshaj qhov Kevlar analog. "Polymers nyob ib puag ncig peb," nws hais tias "Lawv ua txhua yam."Xav txog kev tig ntau yam ntawm cov polymers, txawm tias cov kab txawv uas tuaj yeem ua hluav taws xob lossis lub teeb, ua cov yeeb yaj kiab nyias uas tuaj yeem npog ntau qhov chaw, nws hais ntxiv. Stano hais.
Hauv lub ntiaj teb uas nyob ib puag ncig los ntawm cov yas, tib neeg muaj laj thawj txaus siab rau lwm cov polymer tshiab uas nws cov khoom siv yog dab tsi tab sis zoo tib yam, Strano hais tias.Qhov aramid no tsis tshua muaj zog, uas txhais tau hais tias peb tuaj yeem hloov cov yas niaj hnub, los ntawm cov xim rau lub hnab mus rau ntim khoom noj, nrog cov ntaub ntawv tsawg dua thiab muaj zog dua.Strano ntxiv tias los ntawm qhov pom kev ruaj khov, qhov super-muaj zog 2D polymer yog ib kauj ruam ntawm txoj hauv kev kom tso lub ntiaj teb los ntawm yas.
Shi En Kim (raws li nws feem ntau hu ua Kim) yog tus kws sau ntawv ywj pheej ntawm Malaysian yug thiab Nrov Science Spring 2022 editorial intern.Nws tau sau ntau yam ntawm cov ncauj lus xws li kev siv cov cobwebs - tib neeg lossis kab laug sab lawv tus kheej - rau cov neeg khaws khib nyiab. hauv qhov chaw sab nrauv.
Boeing's Starliner spacecraft tseem tsis tau mus txog qhov chaw nres tsheb thoob ntiaj teb, tab sis cov kws tshaj lij tau pom zoo txog qhov kev sim thib peb.
Peb yog ib tus neeg koom nrog Amazon Services LLC Associates Program, ib qho kev koom tes tshaj tawm kev tshaj tawm 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 nrog. Kev sau npe lossis siv lub vev xaib no suav nrog kev lees txais peb Cov Cai Kev Pabcuam.
Post lub sij hawm: May-19-2022