Ngā mihi nui ki a koe mō tō rēhitatanga ki te Ao Ā-tinana. Mena kei te hiahia koe ki te whakarerekē i ō taipitopito i tētahi wā, tēnā tirohia taku pūkete.
Ka taea e ngā kiriata karāpiti te tiaki i ngā taputapu hiko mai i te irahiko hikohiko (EM), engari ko ngā tikanga o nāianei mō te hanga i aua mea ka roa mō ētahi hāora, ā, me tae ki te pāmahana tukatuka tata ki te 3000 °C. Kua whakaatuhia e tētahi rōpū kairangahau mai i te Shenyang National Laboratory for Materials Science i te Chinese Academy of Sciences tētahi huarahi kē atu mō te hanga kiriata karāpiti kounga teitei i roto i ētahi hēkona noa iho mā te tinei i ngā rīpene wera o te pepa nikara ki roto i te etanoru. Ko te tere tipu mō ēnei kiriata he nui ake i te rua ngā whakarea teitei ake i ngā tikanga o nāianei, ā, he rite tonu te kawe hiko me te kaha miihini o ngā kiriata ki ērā o ngā kiriata i hangaia mā te whakamahi i te whakatakotoranga kohu matū (CVD).
Ka whakaputahia e ngā taputapu hiko katoa ētahi hihi EM. I te iti haere o ngā taputapu, ā, i te teitei haere o ngā auau mahi, ka piki haere te pūmanawa mō te wawaotanga hikohiko (EMI), ā, ka pā kino pea ki te mahi a te taputapu me ngā pūnaha hiko tata.
Ko te graphite, he allotrope o te waro i hangaia mai i ngā paparanga graphene e puritia ana e ngā kaha van der Waals, he maha ngā āhuatanga hiko, wera me te miihini whakamiharo e hanga ana hei parepare whai hua ki te EMI. Heoi, me noho hei āhua angiangi rawa kia nui ai te kawe hiko, he mea nui tēnei mō ngā tono EMI mahi nā te mea ko te tikanga ka taea e te rauemi te whakaata me te mimiti i ngā ngaru EM i a rātou e taunekeneke ana me ngā kaikawe utu i roto.
I tēnei wā, ko ngā huarahi matua mō te hanga kiriata karāhe ko te whakakorikori pāmahana teitei o ngā pūhui kakara, te whakarārangi rānei i te waikura karāhe (GO) me ngā pepa nano karāhe, paparua i te paparua. E rua ngā tukanga e hiahia ana ki ngā pāmahana teitei o te 3000 °C me te wā tukatuka o te hāora. I roto i te CVD, he iti ake ngā pāmahana e hiahiatia ana (i waenga i te 700 ki te 1300 °C), engari he torutoru hāora te roa hei hanga kiriata matotoru-nanomita, ahakoa i roto i te korehau.
Kua hangaia e tētahi tīma i arahina e Wencai Ren he kiriata karāhe kounga teitei, tekau ngā nanometa te matotoru i roto i ētahi hēkona ruarua mā te whakamahana i te pepa nikara ki te 1200 °C i roto i te āhuarangi argon, kātahi ka tere te tuku i tēnei pepa ki roto i te etanoru i te 0 °C. Ka horapa ngā ngota waro i puta mai i te pirau o te etanoru, ka rewa ki roto i te nikara nā te wairewatanga waro teitei o te konganuku (0.4 wt% i te 1200 °C). Nā te mea ka tino heke te wairewatanga waro i te pāmahana iti, ka wehea ngā ngota waro, ka puta mai i te mata o te nikara i te wā e tinei ana, ka puta he kiriata karāhe matotoru. E ai ki ngā kairangahau, ko te mahi whakatere pai rawa atu o te nikara ka āwhina hoki i te hanganga o te karāhe he tino tioata.
Mā te whakamahi i te huinga o te karuārai tuku taumira teitei, te whakarara hihi-X me te tirotiro Raman, i kitea e Ren mā ko te karāpiti i hangaia e rātou he tino tioata ki runga i ngā wāhi whānui, he pai te paparanga, ā, kāore he hapa e kitea ana. Ko te kawe hiko o te kiriata he teitei ki te 2.6 x 105 S/m, he rite ki ngā kiriata i whakatipuria mā te CVD, mā ngā tikanga pāmahana-tiketike rānei me te pēhi i ngā kiriata GO/graphene.
Hei whakamātautau i te pai o te ārai a te rauemi i te hihi EM, i whakawhitihia e te tīma ngā kiriata he 600 mm2 te whānui o te mata ki runga i ngā papa i hangaia ki te polyethylene terephthalate (PET). Kātahi ka inehia e rātou te whai huatanga o te parenga EMI (SE) o te kiriata i te awhe auau X-band, i waenga i te 8.2 me te 12.4 GHz. I kitea e rātou he EMI SE neke atu i te 14.92 dB mō te kiriata he 77 nm te matotoru. Ka piki ake tēnei uara ki te neke atu i te 20 dB (te uara iti rawa e hiahiatia ana mō ngā tono arumoni) i roto i te X-band katoa ina whakarārangihia e rātou ētahi atu kiriata. Ina hoki, ko te kiriata kei roto e rima ngā wahi o ngā kiriata graphite kua whakarārangihia (tata ki te 385 nm te matotoru katoa) he EMI SE tata ki te 28 dB, ko te tikanga ka taea e te rauemi te ārai i te 99.84% o te hihi taunga. I te katoa, i inehia e te tīma he parenga EMI o te 481,000 dB/cm2/g puta noa i te X-band, he pai ake i ngā rauemi hangai katoa i kōrerotia i mua.
E ai ki ngā kairangahau, ki tā rātou mōhiotanga pai rawa atu, ko tā rātou kiriata karāhe te mea angiangi rawa o ngā rauemi tiaki kua pūrongohia, me te mahi tiaki EMI ka taea te whakatutuki i te hiahia mō ngā tono arumoni. He pai hoki ōna āhuatanga miihini. Ko te kaha pakaru o te rauemi o te 110 MPa pea (i tangohia mai i ngā kōpiko ahotea-taumahatanga o te rauemi i whakatakotoria ki runga i te tautoko polycarbonate) he teitei ake i te kaha o ngā kiriata karāhe i whakatipuria e ngā tikanga kē atu. He ngāwari hoki te kiriata, ā, ka taea te piko 1000 ngā wā me te radius piko o te 5 mm me te kore e ngaro ōna āhuatanga tiaki EMI. He pumau hoki ki te wera tae atu ki te 550 °C. E whakapono ana te tīma ko ēnei āhuatanga me ētahi atu āhuatanga te tikanga ka taea te whakamahi hei rauemi tiaki EMI tino angiangi, māmā, ngāwari me te whai hua mō ngā tono i roto i ngā wāhi maha, tae atu ki te rererangi me ngā hikohiko me ngā optoelectronics.
Pānuihia ngā whanaketanga tino hira me ngā whanaketanga whakahihiri o te pūtaiao rauemi i roto i tēnei hautaka urunga tuwhera hou.
Ko Physics World tētahi wāhanga nui o te kaupapa a IOP Publishing ki te whakapuaki i ngā rangahau me ngā mahi auaha o te ao ki te hunga whānui. Ko te paetukutuku tētahi wāhanga o te kohinga Physics World, he kohinga ratonga mōhiohio ipurangi, matihiko me te tānga mō te hapori pūtaiao o te ao.
Wā tuku: Mei-07-2020