Scientists have designed a nature-inspired carbon tube aerogel thermal insulating material based upon the microstructure of polar bear hair. This lightweight, highly-elastic and more efficient heat insulator opens up new avenues for energy-efficient building insulation
Bear ya polar hair helps the animal to prevent heat loss in cold and humid climatic conditions in the frigid Arctic circle. Polar bear hair is naturally hollow unlike human hair or other mamalia. Each hair strand has a long, cylindrical core running through its center. It is this shape and spacing of the cavities which gives polar bear hair the distinct white coat. These cavities have multitude of properties like exceptional heat-holding, water resistance, elasticity etc. which makes them a very good thermal insulator material. The hollow centers restrict movement of heat while design-wise making every strand extremely lightweight. Also, the non-wettable nature of polar bear hair keeps the animal warm when they are swimming in sub-zero temperatures and also under humid conditions. Polar bear hair is thus a very good model for designing synthetic materials which can provide efficient insulation from heat just like polar bear hair does it naturally.
Katika utafiti mpya uliochapishwa mnamo Juni 6 mnamo Chem, wanasayansi wameunda kihami riwaya kinachochukua msukumo kutoka na kuiga muundo mdogo wa nywele za dubu binafsi na hivyo kupata sifa zake zote za kipekee. Walitengeneza mamilioni ya mirija ya kaboni iliyo na mashimo yenye uzani mwepesi, kila moja ikiwa na urefu wa uzi mmoja wa nywele na kuziweka kwenye kizuizi cha airgel. Mchakato wa kubuni ulianza kwanza kwa kutengeneza kebo ya hidrojeli kutoka kwa nanowires ya tellurium (Te) kama kiolezo ambacho kilipakwa ganda la kaboni. Kisha wakatengeneza airgel ya mirija ya kaboni (CTA) kutoka kwa hidrojeli hii kwa kuikausha kwanza na kisha kuiweka katika angahewa isiyo na hewa ya argon kwenye 900 °C ili kuondoa Te nanowires. Muundo huu wa kipekee huifanya CTA kuwa kizio bora zaidi cha kuhami joto na pia asili ya elastic zaidi inapojirudia kwa kasi ya 1434 mm/s. Hii ndiyo kasi zaidi kuwahi kulinganishwa na vifaa vyote vya kawaida vya elastic. Waandishi wanasema kuwa ni elastic zaidi kuliko nywele za polar.
Kwa sababu ya muundo wa mashimo ya mirija ya kaboni, nyenzo huonyesha upitishaji bora wa joto ambao ni wa chini kuliko ule wa hewa kavu kutokana na kipenyo cha ndani cha nyenzo kuwa chini ya njia ya bure ya hewa. Nyenzo zilionyesha maisha marefu kwa kudumisha conductivity yake ya joto baada ya kuhifadhiwa kwa muda wa miezi 3 kwenye joto la kawaida na unyevu wa 56%. CTA ni nyepesi na wiani wa kilo 8 / m3; nyepesi kuliko nyenzo nyingi za kihami joto zinazopatikana. Haiathiriwi na maji kwani haina unyevu. Pia, muundo wa mitambo ya CTA hudumishwa hata baada ya mizunguko mingi ya kutolewa kwa compress kwenye aina tofauti.
Utafiti wa sasa unafafanua mirija ya hewa ya kaboni mpya – iliyochochewa kutoka kwa muundo wa mirija ya mirija ya dubu ya ncha ya ncha ya nywele - ambayo hufanya kazi kama kihami bora cha joto. Ikilinganishwa na vifaa vingine vya kuhami hewa vinavyopatikana, muundo huu wa mirija iliyohamasishwa na dubu-polar ni nyepesi kwa uzito, sugu zaidi kwa mtiririko wa joto, hustahimili maji na haiharibiki maishani mwake.
Improved and more efficient thermal insulation systems hold promise for conserving primary energy consumption. Nishati is now in short supply while nishati costs are escalating. One of the ways to conserve energy is to improve thermal insulation of majengo. Aerogels tayari zinaonyesha ahadi kubwa kwa anuwai ya matumizi kama haya. Utafiti huu unafungua njia za kubuni nyenzo za utendaji wa juu ambazo ni uzani mwepesi, elastic zaidi na kuhami joto kwa matumizi katika majengo, tasnia ya anga haswa katika mazingira yaliyokithiri. Kwa sababu ya uwezo wake wa kunyoosha uliokithiri, rufaa yake inaimarishwa kwa matumizi mbalimbali.
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Chanzo (s)
Zhan, H na al. 2019. Airgel ya Tube ya Kaboni ya Biomimetic Huwasha Unyunyuzishaji wa Juu na Uhamishaji joto. Chem. http://dx.doi.org/10.1016/j.chempr.2019.04.025
