Enkosi ngokubhalisa kunye nePhysics World Ukuba ungathanda ukutshintsha iinkcukacha zakho nangaliphi na ixesha, nceda undwendwele iakhawunti yam
Iifilim zegraphite zinokukhusela izixhobo zombane kwimitha ye-electromagnetic (EM), kodwa iindlela zangoku zokuzenza zithatha iiyure ezininzi kwaye zifuna amaqondo obushushu amalunga ne-3000 °C. Iqela labaphandi abavela kwiLebhu yeSizwe yeShenyang yeSayensi yeZizinto kwi-Chinese Academy of Sciences ngoku ibonise enye indlela yokwenza iifilimu zegraphite ezikumgangatho ophezulu kwimizuzwana nje embalwa ngokucima imicu eshushu ye-nickel foil kwi-ethanol. Izinga lokukhula kwezi bhanyabhanya lingaphezulu kweeodolo ezimbini zobukhulu kuneendlela ezikhoyo, kwaye ukusebenza kombane kwefilimu kunye namandla omatshini alingana nezo zeefilim ezenziwe kusetyenziswa ikhemikhali yokubeka umphunga (CVD).
Zonke izixhobo zombane zivelisa imitha ye-EM. Njengoko izixhobo zisiya zisiba ncinci kwaye zisebenza kumaza aphezulu naphezulu, amandla okuphazamiseka kombane wombane (EMI) ayakhula, kwaye anokuchaphazela kakubi ukusebenza kwesixhobo kunye nokweenkqubo zombane ezikufutshane.
Igraphite, iallotrope yekhabhoni eyakhiwe ukusuka kumaleko egraphene ebanjwe kunye yivan der Waals forces, inenani leempawu eziphawulekayo zombane, ezishushu kunye nezomatshini ezenza ibe ikhaka elisebenzayo ngokuchasene ne-EMI. Nangona kunjalo, kufuneka ibe kwimo yefilimu ebhityileyo kakhulu ukuze ibe nombane ophezulu wokuhamba kombane, okubalulekileyo kwizicelo ezisebenzayo ze-EMI kuba ithetha ukuba izinto eziphathekayo zinokubonakalisa kwaye zifunxe amaza e-EM njengoko zisebenzisana nabathwali bentlawulo ngaphakathi. yona.
Okwangoku, iindlela eziphambili zokwenza ifilimu yegraphite ibandakanya ipyrolysis yobushushu obuphezulu beepolymers ezinuka kamnandi okanye ukupakisha igraphene (GO) oxide okanye igraphene nanosheets layer by layer. Zombini ezi nkqubo zifuna amaqondo obushushu aphezulu malunga ne-3000 °C kunye namaxesha okusebenza eyure. Kwi-CVD, amaqondo obushushu afunekayo asezantsi (phakathi kwe-700 ukuya kwi-1300 °C), kodwa kuthatha iiyure ezimbalwa ukwenza iifilimu ezityebileyo ze-nanometre, nakwi-vacuum.
Iqela elikhokelwa ngu-Wencai Ren ngoku livelise ifilimu yegraphite ekumgangatho ophezulu amashumi eenanometers atyebileyo kwimizuzwana embalwa ngokufudumeza ifoyile yenickel ukuya ku-1200 °C kwi-argon atmosphere kwaye ngokukhawuleza incwiliselwa le foil kwi-ethanol ku-0 °C. Iiathom zekhabhoni eziveliswe ekuboleni kwe-ethanol zisasazeke kwaye zinyibilike kwi-nickel enkosi kwisinyithi sokunyibilika kwekhabhoni ephezulu (0.4 wt% kwi-1200 °C). Ngenxa yokuba oku kunyibilika kwekhabhoni kuncipha kakhulu kumaqondo obushushu aphantsi, iiathom zekhabhoni ziye zahlulahlulwe kwaye zigqithise kumphezulu we-nickel ngexesha lokucima, zivelisa ifilimu eshinyeneyo yegraphite. Abaphandi baxela ukuba umsebenzi ogqwesileyo we-nickel unceda nasekuyilweni kwe-crystalline graphite.
Ukusebenzisa indibaniselwano ye-high-resolution transmission microscopy, i-X-ray diffraction kunye ne-Raman spectroscopy, uRen kunye noogxa bafumanisa ukuba igraphite abayivelisayo yayiyikristale kakhulu kwiindawo ezinkulu, ifakwe kakuhle kwaye ingenaziphene ezibonakalayo. I-electron conductivity yefilimu yayiphezulu njenge-2.6 x 105 S / m, efana neefilimu ezikhuliswe yi-CVD okanye ubuchule obuphezulu bobushushu kunye nokucinezela iifilimu ze-GO / graphene.
Ukuvavanya indlela izinto ezinokuthi zithintele ngayo i-EM radiation, iqela ladlulisela iifilimu ezinommandla we-600 mm2 kwi-substrates eyenziwe nge-polyethylene terephthalate (PET). Baye ke balinganisa ifilimu ye-EMI ukukhusela ukusebenza kakuhle (SE) kuluhlu lwamaza e-X-band, phakathi kwe-8.2 kunye ne-12.4 GHz. Bafumene i-EMI SE engaphezulu kwe-14.92 dB yefilimu emalunga ne-77 nm ubukhulu. Eli xabiso linyuka ukuya ngaphezu kwe-20 dB (ixabiso elincinci elifunekayo kwizicelo zorhwebo) kuyo yonke i-X-band xa bedibanisa iifilimu ezininzi kunye. Ngokwenene, ifilim equlathe iziqwenga ezihlanu zeefilim zegraphite ezipakishweyo (malunga ne-385 nm ubukhulu bebonke) ine-EMI SE ejikeleze i-28 dB, into ethetha ukuba imathiriyeli inokuthintela i-99.84% ye-radiation yesehlo. Ngokubanzi, iqela lilinganisa ukukhuselwa kwe-EMI kwe-481,000 dB / cm2 / g ngaphesheya kwe-X-band, idlula zonke izinto ezenziwe ngaphambili ezixelwe ngaphambili.
Abaphandi bathi ngokolona lwazi lwabo, ifilimu yabo yegraphite yeyona ibhityileyo phakathi kwezinto ezichaziweyo zokukhusela, kunye ne-EMI ekhuselayo yokusebenza enokwanelisa imfuno yezicelo zorhwebo. Iimpawu zayo zoomatshini nazo zifanelekile. Amandla okuphuka kwemathiriyeli amalunga ne-110 MPa (ecatshulwe kuxinzelelo-igophe loxinzelelo lwemathiriyeli ebekwe kwinkxaso yepolycarbonate) iphezulu kunaleyo yeefilim zegraphite ezikhuliswe zezinye iindlela. Ifilimu iyaguquguquka, nayo, kwaye inokugotywa amaxesha angama-1000 kunye ne-radius yokugoba ye-5 mm ngaphandle kokulahlekelwa iipropati zayo zokukhusela i-EMI. Ikwazinzile ngokobushushu ukuya kuma-550 °C. Iqela likholelwa ukuba ezi kunye nezinye iipropati zithetha ukuba zingasetyenziswa njenge-ultrathin, i-lightweight, i-flexible kunye ne-EMI esebenzayo yokukhusela imathiriyeli kwizicelo kwiindawo ezininzi, kubandakanywa i-aerospace kunye ne-electronics kunye ne-optoelectronics.
Funda eyona nkqubela ibalulekileyo nenika umdla kwisayensi yezixhobo kule jenali entsha yofikelelo oluvulekileyo.
I-Physics World imele inxalenye ephambili ye-IOP Publishing's mission yokunxibelelana ngophando olukumgangatho wehlabathi kunye nokuveliswa kwezinto ezintsha kwabona baphulaphuli banzi. Iwebhusayithi iyinxalenye yepotfoliyo yePhysics World, ingqokelela yeenkonzo zolwazi ezikwi-intanethi, zedijithali kunye noshicilelo kuluntu lwehlabathi lwenzululwazi.
Ixesha lokuposa: May-07-2020